Construction method and device of database for microbial identification and identification method and system

Abstract

The invention discloses a construction method and device of a database for microbial identification and an identification method and system. The construction method of the database comprises the following steps: collecting a blood culture positive sample set and a blood culture negative sample set; respectively processing the blood culture positive sample set and the blood culture negative sample set by adopting a microorganism enrichment method to obtain a positive microorganism set and a processed negative sample set; respectively carrying out mass spectrum identification on the positive microorganism set and the treated negative sample set by adopting a mass spectrometry to obtain a positive sample set mass spectrum and a negative sample set mass spectrum; obtaining a non-pathogenic bacterium protein characteristic peak according to the negative sample set mass spectrum; and obtaining a conserved characteristic peak and an exclusive characteristic peak of each positive microorganism according to the positive sample set mass spectrum and the standard culture reference spectrum. By utilizing the constructed database, the influence of interference factors such as plasma protein, platelets and cell debris in the blood culture bottle can be eliminated, the identification accuracy is improved, the identification time is shortened, and the identification efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of microbial identification, and in particular to a method and device for constructing a database for microbial identification, and an identification method and system. Background Art

[0002] Bloodstream infection is a serious systemic infectious disease that is prone to induce sepsis and multiple organ dysfunction syndrome (MODS) and has a high mortality rate. It has become one of the major public health burdens worldwide. The mortality rate of bloodstream infection is high, and timely and accurate identification of bloodstream infection pathogens is crucial to optimize antimicrobial treatment and improve patient prognosis. At present, the "gold standard" for diagnosing bloodstream infection at home and abroad is still blood culture. The traditional identification method takes at least 48 hours after the blood culture is positive. The pathogen identification time is long, and interfering factors such as white blood cells and platelets in the blood will interfere with the microbial spectrum isolated from the blood culture, thereby affecting the identification, resulting in a low success rate of pathogen identification. Summary of the invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a method and device for constructing a database for microbial identification, an identification method and system, an electronic device and a storage medium.

[0004] In a first aspect, a method for constructing a database for microbial identification is provided, comprising:

[0005] Collect blood culture positive and blood culture negative sample sets;

[0006] The blood culture positive sample set and the blood culture negative sample set are processed respectively by using a microbial enrichment method to obtain a positive microbial set and a processed negative sample set;

[0007] Using mass spectrometry to perform mass spectrometry identification on the positive microorganism set and the processed negative sample set, respectively, to obtain a mass spectrum of the positive sample set and a mass spectrum of the negative sample set;

[0008] Acquire non-pathogenic bacteria protein characteristic peaks according to the mass spectrum of the negative sample set;

[0009] The conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism are obtained according to the mass spectrum of the positive sample set and the standard culture reference spectrum.

[0010] In a second aspect, a device for constructing a database for microbial identification is provided, comprising:

[0011] A collection module, used for collecting a blood culture positive sample set and a blood culture negative sample set;

[0012] A processing module, used to process the blood culture positive sample set and the blood culture negative sample set respectively by using a microorganism enrichment method to obtain a positive microorganism set and a processed negative sample set;

[0013] A mass spectrometry identification module, used to perform mass spectrometry identification on the positive microorganism set and the processed negative sample set respectively by mass spectrometry to obtain a mass spectrum of the positive sample set and a mass spectrum of the negative sample set;

[0014] A first acquisition module is used to acquire non-pathogenic bacteria protein characteristic peaks according to the mass spectrum of the negative sample set;

[0015] The second acquisition module is used to acquire the conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism according to the mass spectrum of the positive sample set and the standard culture reference spectrum.

[0016] In a third aspect, a method for identifying a microorganism is provided, comprising:

[0017] Constructing a database, wherein the database includes characteristic peaks of non-pathogenic bacteria proteins of negative samples and conservative characteristic peaks and exclusive characteristic peaks corresponding to at least one positive microorganism;

[0018] Obtaining a mass spectrum of a positive sample to be tested;

[0019] Preprocessing the mass spectrum of the positive sample to be tested, and identifying the characteristic peaks of non-pathogenic bacteria proteins according to the constructed database to obtain the preprocessed mass spectrum of the positive sample to be tested;

[0020] The ion peaks in the mass spectrum of the pre-treated positive sample to be tested are compared with the conservative characteristic peaks and exclusive characteristic peaks of the positive microorganisms in the database, the positive sample to be tested is identified, and the species of the positive sample to be tested is determined.

[0021] In a fourth aspect, a microbial identification system is provided, comprising:

[0022] A database construction module is used to construct a database for microbial identification;

[0023] A test sample acquisition module is used to obtain a mass spectrum of a positive sample to be tested;

[0024] A preprocessing module is used to preprocess the mass spectrum of the positive sample to be tested, and identify the characteristic peaks of non-pathogenic bacteria proteins according to the constructed database to obtain the preprocessed mass spectrum of the positive sample to be tested;

[0025] The microorganism identification module is used to compare the ion peaks in the mass spectrum of the pre-treated positive sample to be tested with the conservative characteristic peaks and exclusive characteristic peaks of the positive microorganisms in the database, identify the positive sample to be tested, and determine the species of the positive sample to be tested.

[0026] In a fifth aspect, an electronic device is provided, including:

[0027] one or more processors;

[0028] a memory for storing one or more programs,

[0029] When one or more programs are executed by one or more processors, the one or more processors execute the method for constructing a database for microorganism identification as provided in the embodiments of the present application, or execute the method for identifying microorganisms as provided in the embodiments of the present application.

[0030] In a sixth aspect, a computer-readable storage medium storing a computer program is provided, which, when executed by a processor, implements a method for constructing a database for microbial identification as provided in the various embodiments of the present application, or executes a method for identifying microorganisms as provided in the various embodiments of the present application.

[0031] According to the technical solution provided in the embodiment of the present application, the present application provides a method and device for constructing a database for microbial identification, an identification method and system, an electronic device and a storage medium. The database constructed by the method for constructing a database for microbial identification of the present application includes characteristic peaks of non-pathogenic bacteria proteins. When identifying pathogens of bloodstream infection, the interference of non-pathogenic bacteria proteins introduced by interfering substances such as plasma proteins, platelets, and cell fragments in blood culture bottles can be eliminated, thereby improving the accuracy of identification, shortening the identification time, and improving the efficiency of identification. Moreover, the constructed database contains conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism. When identifying pathogens of bloodstream infection, the specific type of pathogens can be quickly identified, thereby improving the accuracy and efficiency of the identification results. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0033] Figure 1 An exemplary flowchart of a method for constructing a microorganism identification database provided in an embodiment of the present application;

[0034] Figure 2 The spectrum of different concentrations of Escherichia coli added to the blood culture bottle provided in the embodiment of the present application;

[0035] Figure 3Peak matrix analysis diagram of 6 blood culture negative samples provided in the embodiment of the present application;

[0036] Figure 4 A peak matrix analysis diagram comparing a blood culture positive sample collection spectrum provided in an embodiment of the present application with a standard culture reference spectrum;

[0037] Figure 5 An exemplary structural block diagram of a device for constructing a database for microbial identification provided in an embodiment of the present application;

[0038] Figure 6 An exemplary flow chart of a microbial identification method provided in an embodiment of the present application;

[0039] Figure 7 An exemplary structural block diagram of a microorganism identification system provided in an embodiment of the present application;

[0040] Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0042] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] After the existing blood culture is reported positive, the components in the positive blood culture bottle are complex. In addition to the culture medium and various cell metabolites, the white blood cells and plasma in the blood will affect the size of the bacterial cell sediment after centrifugation, thereby interfering with mass spectrometry identification. Normal human blood contains about (3.5-5.5)×10 red blood cells. 9 / mL, white blood cells about (4~10)×10 6 / mL, and when the blood culture system reports positive, the concentration of microorganisms in the bottle may be 10 6 -10 9 CFU / ml, excessive blood cells and related proteins will affect the detection of microbial ribosomal proteins. Therefore, in mass spectrometry identification, other components in the blood (such as white blood cells, plasma) will interfere with the spectra of microorganisms isolated from blood culture and thus affect identification. Interference factors also include platelets, lipid particles, plasma enzymes and cell fragments, all of which may lead to a decrease in the success rate of identification.

[0044] To solve the above technical problems, please refer to Figure 1 , shows an exemplary flow chart of a method for constructing a database for microbial identification provided in an embodiment of the present application.

[0045] like Figure 1 As shown, in this embodiment, the present invention provides a method 100 for constructing a database for microorganism identification, and the construction method 100 includes:

[0046] S110: Collect blood culture positive sample set and blood culture negative sample set;

[0047] S120: using a microbial enrichment method to process the blood culture positive sample set and the blood culture negative sample set respectively to obtain a positive microbial set and a processed negative sample set;

[0048] S130: performing mass spectrometry identification on the positive microorganism set and the processed negative sample set respectively by mass spectrometry to obtain a mass spectrum of the positive sample set and a mass spectrum of the negative sample set;

[0049] S140: Acquire characteristic peaks of non-pathogenic bacteria proteins according to the mass spectrum of the negative sample set;

[0050] S150: Obtaining conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism according to the mass spectrum of the positive sample set and the standard culture reference spectrum.

[0051] Specifically, the embodiment of the present application uses the acquired non-pathogenic protein characteristic peaks, the conservative characteristic peaks and the exclusive characteristic peaks of each positive microorganism to construct a database. The non-pathogenic protein characteristic peaks in the constructed database can be used to eliminate the interference of non-pathogenic protein introduced by interfering substances such as plasma proteins, platelets, and cell debris in the blood culture bottle when identifying pathogens of bloodstream infection, thereby improving the accuracy of identification, shortening the identification time, and improving the efficiency of identification. Moreover, the constructed database contains the conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism, and when identifying pathogens of bloodstream infection, the specific type of pathogens can be quickly identified, thereby improving the accuracy and efficiency of the identification results.

[0052] Specifically, in step S110, blood culture is to collect blood samples from patients and inoculate them into culture bottles to discover and identify pathogenic microorganisms that cause bacteremia or fungemia, and is a way to diagnose the cause of bloodstream infection. The automatic blood culture system selects appropriate culture bottles, and then uses appropriate culture methods and various modern detection technologies to automatically and continuously monitor various changes in the culture bottles after inoculation to determine whether there are microorganisms in the culture bottles.

[0053] Positive blood culture: A blood culture is a laboratory test in which blood is drawn from a patient and placed in a bottle containing a culture medium to determine whether the microorganisms (bacteria or fungi) that are causing the patient's infection have entered the patient's bloodstream. For patients, a positive blood culture can confirm the presence of a bloodstream infection.

[0054] Blood culture negative sample set: The blood of different patients is placed in culture bottles and cultured for 5 days. The blood culture samples reported as negative for growth are collected to obtain the blood culture negative sample set.

[0055] Blood culture positive sample set: refers to placing blood infected with different microorganisms in culture bottles to obtain blood culture positive samples of the corresponding microorganisms.

[0056] Positive microorganisms in the blood culture positive sample set include but are not limited to: Staphylococcus aureus, Streptococcus pneumoniae, Enterobacteriaceae, Pseudomonas aeruginosa, Candida albicans, Streptococcus pyogenes, Streptococcus agalactiae, Listeria monocytogenes, Neisseria meningitidis, Neisseria gonorrhoeae, Haemophilus influenzae, Bacteroides fragilis, Cryptococcus neoformans, coagulase-negative staphylococci, viridans streptococci, Micrococcus, Propionibacterium acnes, Bacillus and Corynebacterium. Enterobacteriaceae include but are not limited to: Escherichia coli, Salmonella, Shigella, Yersinia, Klebsiella, Proteus, Edwardsiella, Citrobacter, etc. Corynebacterium includes but is not limited to: Corynebacterium diphtheriae, Corynebacterium pseudodiphtheriae, Corynebacterium siccae, Corynebacterium ulcerans, Corynebacterium hemolyticum, Corynebacterium pyogenes, Corynebacterium jack group, etc.

[0057] In the embodiments of the present application, the culture bottles include but are not limited to: resin aerobic bottles, resin anaerobic bottles and children's bottles.

[0058] In some embodiments, in step S120, the bacterial density of each positive sample in the blood culture positive sample set is not less than 10 8 CFU / mL.

[0059] Specifically, the blood culture bottle that has just reported positive may not be able to enrich to the minimum amount of bacteria that meets the identification requirements due to its low bacterial density, thereby affecting the identification performance of pathogens. In this application, the blood culture is continued to be cultured for 1-2 hours after the positive report, and the bacterial density is not less than 10 8 CFU / mL, high bacterial count, thus improving the detection rate. It should be noted that the culture time after the blood culture is positive should not be too long. Long-term blood culture will also increase the number of non-bacterial sample components (such as cell debris) on the mass spectrometer, which will mask the bacterial signal during the identification process and reduce the spectrum quality, affecting the detection rate.

[0060] In the embodiment of the present application, the blood culture was continued to be cultured for 1-2 hours after the positive result, so that the bacterial density was not less than 108 CFU / mL can improve identification performance. Figure 2 As shown, the present application has experimentally confirmed that as the bacterial concentration decreases, the identification performance decreases significantly. Figure 2 The effect of different concentrations of bacterial solution in blood culture bottles on identification results is shown. The Escherichia coli (E.coli) monoclonal cultured on the blood plate was resuspended in physiological saline, McF was adjusted to 0.5, and after dilution 1000 times, 100 μL was inoculated into the resin aerobic bottle (positive bottle), and 10 mL of defibrinated sheep blood was added to the positive bottle. In parallel, 10 mL of defibrinated sheep blood was injected into a resin aerobic bottle (control bottle) that was not inoculated with bacteria. At the same time, it was placed in the fully automatic blood culture system and grown by shaking at 35°C. After culturing overnight, it was observed that the positive bottle had grown to the plateau phase in the fully automatic blood culture system. The culture of the positive bottle was taken out with a sterile syringe, and the culture solution in the control bottle was used to dilute the culture of the positive bottle 10 times, dilute 5 gradients, and count the plates. The 5 gradient dilutions and the control bottle samples were extracted using the blood culture positive sample pretreatment kit, and the extracts were used for mass spectrometry detection.

[0061] In some embodiments, in step S120, the microorganism enrichment method includes at least one of the following: a blood culture positive sample pretreatment kit method, a separation gel coagulation tube method, and a differential centrifugation method.

[0062] Specifically, the blood culture positive sample pretreatment kit method includes: BioMérieux MS Blood Culture Kit (RUO), Bruker MBT IVD Kit, any of the blood culture positive sample pretreatment kits provided by patent publication number CN 111778175A. Except for the lysis and filtration method used by BioMerieux, the conventional commercial versions of blood culture positive sample pretreatment kits all use lysis and centrifugation methods. In the embodiments of the present application, the separation gel coagulation tube method or differential centrifugation method can also be used to process the blood culture positive sample set, so that the bacteria in the blood culture positive sample can be enriched to meet the minimum bacterial count required for identification.

[0063] In the embodiment of the present application, the blood culture positive sample set and the blood culture negative sample set are processed respectively by a microbial enrichment method, so that the processing conditions of the negative samples and the positive samples are the same, which is conducive to the subsequent construction of a database.

[0064] In some embodiments, in step S130, mass spectrometry is used to perform mass spectrometry identification on the processed negative sample set to obtain a mass spectrum of the negative sample set, including:

[0065] The processed negative sample set includes M negative samples, and each negative sample is sampled at least N times to obtain M×N negative sample mass spectra, that is, the negative sample set mass spectra include M×N negative sample mass spectra; wherein M and N are natural numbers greater than or equal to 1 respectively.

[0066] Specifically, the mass spectrometry method uses MALDI-TOF MS (Matrix-assisted laser desorption / ionization-time offlight mass spectrometry), which is a new technology for microbial identification, which has the advantages of rapid, accurate and convenient identification. The blood culture positive sample set is processed by microbial enrichment method, and MALDI-TOF MS can be directly used for identification, which greatly improves the identification speed, shortens the reporting time, and meets the needs of clinical rapid diagnosis.

[0067] Among them, the mass spectrometry method is specifically: each negative sample in the negative sample set processed in step S120 is spotted by formic acid direct coating method or extraction method, the number of times each negative sample is spotted is N, preferably N is three times, and then the parameters of the MALDI-TOF MS mass spectrometer are set, and mass spectrometry is performed on each negative sample, and N mass spectra are obtained for each negative sample.

[0068] Exemplary, the extraction method is:

[0069] Add 20 μL of 70% formic acid to the sample (negative sample or positive sample), and mix well with a pipette; add 20 μL of acetonitrile, mix well, and centrifuge at 12000 rpm for 2 min; draw 1 μL of supernatant onto the sample target, cover with 1 μL of matrix solution after drying, and detect on the machine (mass spectrometer) after drying.

[0070] The parameters of the mass spectrometer are as follows: linear mode, acceleration voltage 20 kV, acquisition frequency 1 GHz, pulse voltage 1.3 kV, laser frequency 50 Hz, spectrum accumulation number 200 shots, single acquisition number 50 shots, cumulative bombardment number of each spectrum 4, initial laser intensity 7%, peak search tolerance 1000 ppm. In the embodiments of the present application, the mass spectrometer parameters are only exemplary, and those skilled in the art can also adjust the parameters of the mass spectrometer according to actual needs.

[0071] In the embodiment of the present application, the processed negative sample set includes M negative samples, and the larger the value of M is set, the better. Preferably, M is set to be no less than 20.

[0072] In some embodiments, in step S140, obtaining characteristic peaks of non-pathogenic bacteria proteins according to the mass spectrum of the negative sample set includes:

[0073] Obtain the ion peak intensity corresponding to each mass-to-charge ratio from the mass spectrum of the negative sample set, record the number of times the same mass-to-charge ratio appears in the mass spectrum of the negative sample set, and calculate the average intensity of the ion peak corresponding to the same mass-to-charge ratio;

[0074] If in the mass spectrum of the negative sample set, there is an ion peak corresponding to the same mass-to-charge ratio, the average intensity of which is not less than the first intensity threshold, and the mass-to-charge ratio appears at least once in the N mass spectra corresponding to each negative sample, and the number of appearances m in the mass spectrum of the negative sample set is: M≤m≤M×N; then the ion peak corresponding to the mass-to-charge ratio is a characteristic peak of non-pathogenic bacteria protein, and all characteristic peaks of non-pathogenic bacteria proteins of the negative samples are obtained.

[0075] Specifically, the average intensity of the ion peak corresponding to the same mass-to-charge ratio is: the sum of the ion peak intensities corresponding to the same mass-to-charge ratio in the mass spectrum of the negative sample set divided by the number of times the mass-to-charge ratio appears in the mass spectrum of the negative sample set. The first intensity threshold can be set to 1000 or other values.

[0076] For example, 6 blood culture negative samples are taken as an example to illustrate the method for obtaining the characteristic peaks of non-pathogenic bacteria proteins, as follows:

[0077] The six collected negative samples (the six negative samples were blood from different patients and did not contain microorganisms such as bacteria and fungi) were processed using a blood culture positive sample pretreatment kit. Mass spectrometry data was collected at three parallel targets for each negative sample, and the data of each three consecutive targets were three repeated results of the same sample. In the peak matrix view of the mass spectrometry software, the negative blood culture bottle data were dragged and dropped in batches, with three spectra for each negative sample, for a total of 18 negative sample spectra. The statistical analysis software EX-Smartspec was used to align the data of the 18 negative sample spectra and perform peak analysis, as shown in Figure 2. Figure 3 shown.

[0078] In the 18 negative sample spectra, obtain the ion peak intensity corresponding to each mass-to-charge ratio (m / z, equivalent to the peak position), record the number of times the same mass-to-charge ratio appears in the 18 negative sample spectra, and calculate the average intensity of the ion peak corresponding to the same mass-to-charge ratio. Figure 3 As shown, the mass-to-charge ratio of 3509.1 appears 16 times in the 18 negative sample spectra, and the corresponding average ion peak intensity is 2170; the mass-to-charge ratio of 3488 appears 16 times in the 18 negative sample spectra, and the corresponding average ion peak intensity is 5077.

[0079] If in the 18 negative sample spectra, there is an ion peak corresponding to the same mass-to-charge ratio whose average intensity is not less than the first intensity threshold (such as 1000), and this mass-to-charge ratio appears at least once in the three mass spectra corresponding to each negative sample, and the number of times m appears in the 18 negative sample spectra is: 6≤m≤18; then the ion peak corresponding to this mass-to-charge ratio is a non-pathogenic protein characteristic peak, and all non-pathogenic protein characteristic peaks of negative samples are obtained. Figure 3 As shown, the mass-to-charge ratios corresponding to the characteristic peaks of non-pathogenic bacteria proteins obtained include: 3509.1, 3488.0, 3373.0, 7565.2, 5044.1, etc.

[0080] It should be noted that the embodiment of the present application uses 6 negative samples as an example to illustrate the method for obtaining characteristic peaks of non-pathogenic bacteria proteins in the database. In actual applications, more negative samples, such as 8, 15, 30, 50, etc., can also be used to obtain characteristic peaks of non-pathogenic bacteria proteins.

[0081] In some embodiments, in step S130, mass spectrometry is used to perform mass spectrometry identification on the positive microorganism set to obtain a mass spectrum of the positive sample set;

[0082] The positive microorganism set includes G positive samples, each positive sample includes at least Q strains, and each strain is spotted at least B times; wherein G, Q, and B are natural numbers greater than or equal to 1 respectively;

[0083] Then each positive sample corresponds to Q×B positive sample mass spectra, and G positive samples correspond to G×Q×B positive sample mass spectra, that is, the mass spectrum of the positive sample set includes G×Q×B positive sample mass spectra.

[0084] Specifically, the mass spectrometry MALDI-TOF MS mass spectrometer, the specific processing process is the same as the processing process of the negative sample mentioned above, and this application will not repeat them one by one. This application can set the values ​​of G, Q, and B according to actual needs. For example, G is 5, Q is not less than 5, and B is 3.

[0085] In some embodiments, in step S150, obtaining the conservative characteristic peaks of each positive microorganism according to the mass spectrum of the positive sample set and the standard culture reference spectrum includes:

[0086] S151: Obtain the ion peak intensity corresponding to each mass-to-charge ratio from the Q×B positive sample mass spectra corresponding to each positive sample, and record the number of times n that the same mass-to-charge ratio appears in the Q×B positive sample mass spectra, and calculate the average intensity of the ion peak corresponding to the same mass-to-charge ratio;

[0087] S152: Compare the mass spectra of Q×B positive samples with the spectra of the corresponding positive samples in the standard culture reference spectrum, define the ion peaks that appear at the same peak position in the mass spectra of Q×B positive samples and the spectra of the corresponding positive samples in the standard culture reference spectrum as the conservative characteristic peaks of the positive microorganism, and obtain all the conservative characteristic peaks of the G positive microorganisms in sequence.

[0088] Specifically, the standard culture reference spectrum is a library spectrum under conventional culture conditions, such as blood plate culture conditions. At present, all spectra in the existing database are standard culture reference spectra. The calculation method of the average intensity of the ion peak corresponding to the same mass-to-charge ratio is as described above, and the embodiments of the present application will not be repeated one by one. The mass spectra of Q×B positive samples corresponding to the same positive sample are compared with the spectrum of the corresponding positive sample in the standard culture reference spectrum. If the two have ion peaks that meet certain conditions at the same peak position (mass-to-charge ratio), that is, the two have corresponding ion peaks at the same peak position, the ion peak corresponding to the mass-to-charge ratio can be used as the conservative characteristic peak of the corresponding positive microorganism, thereby obtaining all conservative characteristic peaks of each positive microorganism. The same method is used to obtain all conservative characteristic peaks corresponding to all positive microorganisms, and the library construction of the conservative characteristic peaks corresponding to each positive microorganism in the database is completed.

[0089] In some embodiments, in step S152, the ion peaks appearing at the same peak positions in the mass spectra of the Q×B positive samples and the spectra of the corresponding positive samples in the standard culture reference spectrum are defined as conservative characteristic peaks of the positive microorganism, including:

[0090] If the mass spectra of Q×B positive samples and the spectra of the corresponding positive samples in the standard culture reference spectrum have the same mass-to-charge ratio, the following conditions are met:

[0091] The average intensity of the ion peaks of the mass-to-charge ratio in the mass spectra of Q×B positive samples and the spectra of the standard culture reference spectra corresponding to the positive samples is not less than the second intensity threshold, and the number of times n that the mass-to-charge ratio appears in the mass spectra of Q×B positive samples is: The number of occurrences in the spectra corresponding to positive samples in the standard culture reference spectrum is not less than two-thirds of the total number of spectra corresponding to positive samples in the standard culture reference spectrum;

[0092] The ion peak corresponding to the mass-to-charge ratio that meets the above conditions is taken as the conservative characteristic peak corresponding to the positive microorganism.

[0093] Specifically, the second intensity threshold can be set to 500 or 400, and those skilled in the art can set it to other values ​​according to actual needs. Through the judgment conditions set in the embodiment of the present application, the conservative characteristic peaks of positive microorganisms grown under bleeding culture conditions can be identified.

[0094] For example, taking Escherichia coli extracted from a positive blood culture sample as an example, the method for obtaining the conservative characteristic peaks of Escherichia coli of the present application is described as follows:

[0095] Escherichia coli, including eight strains, including strains A4-A6, B4, B6, C4-C6, each strain was spotted 3 times, and mass spectrometry was performed using a MALDI-TOF MS mass spectrometer to obtain 24 mass spectra of Escherichia coli. The 24 mass spectra of Escherichia coli were compared with the spectra of Escherichia coli ATCC 25922 in the standard culture reference spectrum (B1-B12, 2 spectra were collected for each target point, a total of 24 spectra), and the comparison results are as follows Figure 4 shown.

[0096] In the 24 mass spectra of E. coli, the ion peak intensity corresponding to each mass-to-charge ratio (m / z, equivalent to the peak position) was obtained, and the number of times the same mass-to-charge ratio appeared in the 24 mass spectra of E. coli was recorded, and the average intensity of the ion peak corresponding to the same mass-to-charge ratio was obtained. Figure 4 As shown, the mass-to-charge ratio of 4284.1 appears 23 times in the 24 mass spectra of Escherichia coli, and the corresponding average ion peak intensity is 513; the mass-to-charge ratio of 4431.7 appears 24 times in the 24 mass spectra of Escherichia coli, and the corresponding average ion peak intensity is 626.

[0097] In the 24 Escherichia coli ATCC 25922 spectra in the standard culture reference spectrum, the mass-to-charge ratio of 46122 appears 24 times in the 24 Escherichia coli mass spectra, and the corresponding average ion peak intensity is 1826.

[0098] If the 24 mass spectra of E. coli obtained from blood culture and the 24 spectra of E. coli ATCC25922 in the standard culture spectrum have the same mass-to-charge ratio, the following conditions are met:

[0099] The average intensity of the ion peak of this mass-to-charge ratio in the 24 mass spectra of Escherichia coli obtained from blood culture and the 24 spectra of Escherichia coli ATCC 25922 in the standard culture spectrum is not less than the second intensity threshold (such as 400), and the number of times this mass-to-charge ratio appears in the 24 mass spectra of Escherichia coli obtained from blood culture is n: 16≤n≤24, and the number of times this mass-to-charge ratio appears in the spectrum of the corresponding positive sample in the standard culture reference spectrum is not less than 16 and not more than 24; the ion peak corresponding to the mass-to-charge ratio that meets the above conditions is used as the conservative characteristic peak of the corresponding positive microorganism. Figure 4 It can be seen that the mass-to-charge ratios corresponding to the conservative characteristic peaks of Escherichia coli include: 3932, 4611, 4769, 6250, etc.

[0100] It should be noted that the present embodiment uses one example of Escherichia coli as an example to illustrate the method for obtaining the conservative characteristic peaks of Escherichia coli in the database. In actual applications, more positive samples, such as 4, 10, 15, 17, etc., can also be used to obtain the conservative characteristic peaks of Escherichia coli. The present embodiment uses Escherichia coli as an example to illustrate the method for obtaining the conservative characteristic peaks of Escherichia coli in the database. The methods for obtaining other microorganisms in the database are similar, and the present embodiment will not be listed one by one.

[0101] In some embodiments, in step S150, obtaining the exclusive characteristic peak of each positive microorganism according to the mass spectrum of the positive sample set and the standard culture reference spectrum includes:

[0102] S153: removing non-pathogenic bacteria protein characteristic peaks and conservative characteristic peaks in the Q×B positive sample mass spectra corresponding to each positive sample to obtain processed Q×B positive sample mass spectra;

[0103] S154: Compare the mass spectra of the Q×B positive samples after processing with the spectra of the corresponding positive samples in the standard culture reference spectrum. If there is an ion peak at a certain peak position in the mass spectra of the Q×B positive samples after processing, and there is no ion peak at the corresponding peak position in the spectrum of the corresponding positive sample in the standard culture reference spectrum, then the ion peak corresponding to the peak position is the exclusive characteristic peak of the positive microorganism, and all the exclusive characteristic peaks of the G positive microorganisms are obtained in sequence.

[0104] Specifically, first, according to the characteristic peaks of non-pathogenic protein in the database, the characteristic peaks of non-pathogenic protein in the mass spectra of Q×B positive samples corresponding to the same positive sample are removed, and then the mass spectra of the processed Q×B positive samples are compared with the spectra of the corresponding positive samples in the standard culture reference spectrum. If the two have ion peaks that meet certain conditions at the same peak position (mass-to-charge ratio), that is, the ion peaks that are not in the standard culture reference spectrum, but there are ion peaks in the mass spectrum of the positive sample of blood culture, the ion peaks corresponding to the mass-to-charge ratio can be used as the exclusive characteristic peaks of the corresponding positive microorganism, thereby obtaining all the exclusive characteristic peaks of each positive microorganism. The same method is used to obtain all the exclusive characteristic peaks corresponding to all positive microorganisms, and the construction of the exclusive characteristic peaks corresponding to each positive microorganism in the database is completed.

[0105] In some embodiments, in step S154, if an ion peak exists at a certain peak position in the mass spectra of the processed Q×B positive samples, and there is no ion peak at the corresponding peak position in the spectrum of the corresponding positive sample in the standard culture reference spectrum, then the ion peak corresponding to the peak position is the exclusive characteristic peak of the positive microorganism, including:

[0106] If the mass spectra of Q×B positive samples after processing and the spectra of the corresponding positive samples in the standard culture reference spectrum have the same mass-to-charge ratio, the following conditions are met:

[0107] The average intensity of the ion peaks of the mass-to-charge ratio in the mass spectra of the Q×B positive samples after processing and the spectra of the corresponding positive samples in the standard culture reference spectrum is not less than the third intensity threshold, and the number of occurrences of the mass-to-charge ratio in the mass spectra of the Q×B positive samples is n: The number of occurrences in the spectra corresponding to positive samples in the standard culture reference spectrum is not greater than one third of the total number of spectra corresponding to positive samples in the standard culture reference spectrum;

[0108] The ion peak corresponding to the mass-to-charge ratio that meets the above conditions is taken as the exclusive characteristic peak of the corresponding positive microorganism.

[0109] Specifically, the third intensity threshold can be set to 500 or 400, and those skilled in the art can set it to other values ​​according to actual needs. Through the judgment conditions set in the embodiment of the present application, the exclusive characteristic peaks of positive microorganisms grown under bleeding culture conditions can be identified.

[0110] From the above example Figure 4 It can be seen that if the 24 mass spectra of Escherichia coli obtained by blood culture and the 24 spectra of Escherichia coli ATCC 25922 in the standard culture spectrum have the same mass-to-charge ratio, the following conditions are met:

[0111] The average intensity of the ion peak of this mass-to-charge ratio in the 24 mass spectra of Escherichia coli obtained from blood culture and the 24 spectra of Escherichia coli ATCC 25922 in the standard culture spectrum is not less than the third intensity threshold (such as 400), and the number of times this mass-to-charge ratio appears in the 24 mass spectra of Escherichia coli obtained from blood culture is n: 16≤n≤24, and the number of times it appears in the spectrum of the corresponding positive sample in the standard culture reference spectrum is not more than 8; the ion peak corresponding to the mass-to-charge ratio that meets the above conditions is used as the exclusive characteristic peak of the corresponding positive microorganism. Figure 4 It can be seen that the mass-to-charge ratios corresponding to the exclusive characteristic peaks of Escherichia coli include: 4431, 7151, 7558, etc.

[0112] It should be noted that the embodiment of the present application uses one example of Escherichia coli as an example to illustrate the method for obtaining the exclusive characteristic peak of Escherichia coli in the database. In actual applications, more positive samples, such as 3, 5, 10, 17, etc., can also be used to obtain the exclusive characteristic peak of Escherichia coli. The embodiment of the present application uses Escherichia coli as an example to illustrate the method for obtaining the exclusive characteristic peak of Escherichia coli in the database. The methods for obtaining other microorganisms in the database are similar, and the embodiments of the present application will not be listed one by one.

[0113] In some embodiments, the method 100 further includes:

[0114] S160: setting weight values ​​for all exclusive characteristic peaks of the G positive microorganisms respectively, and setting correction rules according to the weight values ​​corresponding to the exclusive characteristic peaks, and using the correction rules to correct the scores of the corresponding ion peaks of the microorganisms to be tested, to obtain the corrected scores of the corresponding ion peaks of the microorganisms to be tested.

[0115] Specifically, the number of exclusive characteristic peaks possessed by each positive microorganism can be 0, 1, 3, 5, etc. A weight value is assigned to each exclusive characteristic peak possessed by each positive microorganism, and the weight value setting rule is: if a certain exclusive characteristic peak appears more times in all positive microorganisms, the smaller the weight value set for the exclusive characteristic peak; on the contrary, the larger the weight value set. The exclusive characteristic peaks of all positive microorganisms are compared vertically. If a certain exclusive characteristic peak only appears in one microorganism, a larger weight value is assigned to the exclusive characteristic peak.

[0116] In the embodiment of the present application, the exclusive characteristic peaks of each microorganism are compared vertically, and different weight values ​​are assigned to different exclusive characteristic peaks of the microorganism. The weight values ​​are used to correct the scores of the ion peaks corresponding to the microorganisms to be tested. The unique characteristics of blood culture positive samples can be scored and optimized to increase the accuracy of identification.

[0117] In some implementations, in step S160, the correction rule is:

[0118] If the positive microorganism has a certain exclusive characteristic peak, and the microorganism to be tested also has an ion peak at the peak position corresponding to the corresponding exclusive characteristic peak, and the intensity of the ion peak is not less than the fourth intensity threshold, then the corrected score of the ion peak corresponding to the microorganism to be tested = the score value of the ion peak corresponding to the microorganism to be tested + the score value of the ion peak corresponding to the microorganism to be tested × the weight value corresponding to the exclusive characteristic peak;

[0119] If the positive microorganism has an exclusive characteristic peak, and the microorganism to be tested does not have an ion peak at the peak position corresponding to the corresponding exclusive characteristic peak, then the corrected score of the corresponding ion peak of the microorganism to be tested = the score value of the corresponding ion peak of the microorganism to be tested - the score value of the corresponding ion peak of the microorganism to be tested × the weight value corresponding to the exclusive characteristic peak.

[0120] Specifically, the fourth intensity threshold may be 400 or 500, and may be set to other values ​​by a person skilled in the art. Using the above correction rules, the matching score results of the microorganisms to be detected can be corrected for a second time, and the fine scoring results can be corrected based on the matching of the collected spectra and the correction rules during the identification process, supplemented by the preset weight values, to increase the accuracy of the identification of the microorganisms to be detected.

[0121] In the second aspect of the embodiment of the present application, Figure 5 As shown, a device 200 for constructing a database for microorganism identification is provided, and the construction device 200 comprises:

[0122] A collection module 210 is used to collect a blood culture positive sample set and a blood culture negative sample set;

[0123] The processing module 220 is used to process the blood culture positive sample set and the blood culture negative sample set respectively by using a microorganism enrichment method to obtain a positive microorganism set and a processed negative sample set;

[0124] A mass spectrometry identification module 230 is used to perform mass spectrometry identification on the positive microorganism set and the processed negative sample set respectively by mass spectrometry to obtain a mass spectrum of the positive sample set and a mass spectrum of the negative sample set;

[0125] A first acquisition module 240 is used to acquire non-pathogenic bacteria protein characteristic peaks according to the mass spectrum of the negative sample set;

[0126] The second acquisition module 250 is used to acquire the conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism according to the mass spectrum of the positive sample set and the standard culture reference spectrum.

[0127] Specifically, the construction device 200 for the microorganism identification database provided in the embodiment of the present application is used for the construction method 100 for the microorganism identification database provided in any embodiment of the present application. The construction device 200 for the microorganism identification database provided in the embodiment of the present application can be used to construct a database, which includes non-pathogenic protein characteristic peaks, conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism. The non-pathogenic protein characteristic peaks in the constructed database can be used to eliminate the interference of non-pathogenic protein introduced by interfering substances such as plasma proteins, platelets, and cell fragments in the blood culture bottle when identifying the pathogens of bloodstream infection, thereby improving the accuracy of identification, shortening the identification time, and improving the efficiency of identification. And the constructed database contains conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism. When identifying the pathogens of bloodstream infection, the specific type of pathogens can be quickly identified, thereby improving the accuracy and efficiency of the identification results.

[0128] In some implementations, the first acquisition module 240 is configured to:

[0129] Obtain the ion peak intensity corresponding to each mass-to-charge ratio from the mass spectrum of the negative sample set, record the number of times the same mass-to-charge ratio appears in the mass spectrum of the negative sample set, and calculate the average intensity of the ion peak corresponding to the same mass-to-charge ratio;

[0130] If in the mass spectrum of the negative sample set, there is an ion peak corresponding to the same mass-to-charge ratio, the average intensity of which is not less than the first intensity threshold, and the mass-to-charge ratio appears at least once in the N mass spectra corresponding to each negative sample, and the number of appearances m in the mass spectrum of the negative sample set is: M≤m≤M×N; then the ion peak corresponding to the mass-to-charge ratio is a characteristic peak of non-pathogenic bacteria protein, and all characteristic peaks of non-pathogenic bacteria proteins of the negative samples are obtained.

[0131] In some implementations, the second acquisition module 250 is configured to:

[0132] From the Q×B positive sample mass spectra corresponding to each positive sample, obtain the ion peak intensity corresponding to each mass-to-charge ratio, and record the number of times n that the same mass-to-charge ratio appears in the Q×B positive sample mass spectra, and calculate the average intensity of the ion peak corresponding to the same mass-to-charge ratio;

[0133] The mass spectra of Q×B positive samples were compared with the spectra of the corresponding positive samples in the standard culture reference spectrum, and the ion peaks appearing at the same peak positions in the mass spectra of Q×B positive samples and the spectra of the corresponding positive samples in the standard culture reference spectrum were defined as the conservative characteristic peaks of the positive microorganisms, and all the conservative characteristic peaks of the G positive microorganisms were obtained in sequence.

[0134] In some implementations, the second acquisition module 250 is configured to:

[0135] If the mass spectra of Q×B positive samples and the spectra of the corresponding positive samples in the standard culture reference spectrum have the same mass-to-charge ratio, the following conditions are met:

[0136] The average intensity of the ion peaks of the mass-to-charge ratio in the mass spectra of Q×B positive samples and the spectra of the standard culture reference spectra corresponding to the positive samples is not less than the second intensity threshold, and the number of times n that the mass-to-charge ratio appears in the mass spectra of Q×B positive samples is: The number of occurrences in the spectra corresponding to positive samples in the standard culture reference spectrum is not less than two-thirds of the total number of spectra corresponding to positive samples in the standard culture reference spectrum;

[0137] The ion peak corresponding to the mass-to-charge ratio that meets the above conditions is taken as the conservative characteristic peak corresponding to the positive microorganism.

[0138] In some implementations, the second acquisition module 250 is configured to:

[0139] The non-pathogen protein characteristic peaks and conservative characteristic peaks in the Q×B positive sample mass spectra corresponding to each positive sample are removed to obtain the processed Q×B positive sample mass spectra;

[0140] The mass spectra of the Q×B positive samples after the treatment are compared with the spectra of the corresponding positive samples in the standard culture reference spectrum. If there is an ion peak at a certain peak position in the mass spectrum of the Q×B positive samples after the treatment, and there is no ion peak at the corresponding peak position in the spectrum of the corresponding positive sample in the standard culture reference spectrum, then the ion peak corresponding to the peak position is the exclusive characteristic peak of the positive microorganism, and all the exclusive characteristic peaks of the G positive microorganisms are obtained in sequence.

[0141] In some implementations, the second acquisition module 250 is configured to:

[0142] If the mass spectra of Q×B positive samples after processing and the spectra of the corresponding positive samples in the standard culture reference spectrum have the same mass-to-charge ratio, the following conditions are met:

[0143] The average intensity of the ion peaks of the mass-to-charge ratio in the mass spectra of the Q×B positive samples after processing and the spectra of the corresponding positive samples in the standard culture reference spectrum is not less than the third intensity threshold, and the number of occurrences of the mass-to-charge ratio in the mass spectra of the Q×B positive samples is n: The number of occurrences in the spectra corresponding to positive samples in the standard culture reference spectrum is not greater than one third of the total number of spectra corresponding to positive samples in the standard culture reference spectrum;

[0144] The ion peak corresponding to the mass-to-charge ratio that meets the above conditions is taken as the exclusive characteristic peak of the corresponding positive microorganism.

[0145] In some embodiments, the constructing device 200 further includes:

[0146] The weight setting module 260 is used to set weight values ​​for all exclusive characteristic peaks of the G positive microorganisms, and set correction rules according to the weight values ​​corresponding to the exclusive characteristic peaks, and use the correction rules to correct the scores of the corresponding ion peaks of the microorganisms to be tested, so as to obtain the corrected scores of the corresponding ion peaks of the microorganisms to be tested.

[0147] In the third aspect of the embodiment of the present application, Figure 6 As shown, a method 300 for identifying a microorganism is provided, and the identification method 300 comprises:

[0148] S310: constructing a database, wherein the database includes characteristic peaks of non-pathogenic bacteria proteins of negative samples and conservative characteristic peaks and exclusive characteristic peaks corresponding to at least one positive microorganism;

[0149] S320: Obtaining a mass spectrum of the positive sample to be tested;

[0150] S330: preprocessing the mass spectrum of the positive sample to be tested, and identifying the characteristic peaks of non-pathogenic bacteria proteins according to the constructed database to obtain the preprocessed mass spectrum of the positive sample to be tested;

[0151] S340: Compare the ion peaks in the mass spectrum of the pre-processed positive sample to be tested with the conservative characteristic peaks and exclusive characteristic peaks of the positive microorganisms in the database, identify the positive sample to be tested, and determine the species of the positive sample to be tested.

[0152] Specifically, the database constructed using the database construction method provided in any embodiment of the present application can eliminate the interference of non-pathogenic bacterial proteins introduced by interfering substances such as plasma proteins, platelets, and cell fragments in blood culture bottles when identifying positive samples to be tested, and the conservative characteristic peaks and exclusive characteristic peaks in the database can be used to further improve the accuracy of identification, shorten the identification time, increase the identification success rate, and reduce the TAT (shorten the measurement cycle) of bloodstream infection diagnosis.

[0153] Specifically, in step S310, the specific method for constructing the database in the embodiments of the present application is not particularly limited, as long as the constructed database includes the non-pathogenic protein characteristic peaks of the negative sample and the conservative characteristic peaks and exclusive characteristic peaks corresponding to at least one positive microorganism, the non-pathogenic protein characteristic peaks of the negative sample and the conservative characteristic peaks and exclusive characteristic peaks corresponding to the positive microorganism can be used to quickly identify the microorganism to be tested, shorten the identification cycle, and improve the success rate of identification. Preferably, the method for constructing the database can use the method for constructing a microorganism identification database provided in any embodiment of the present application to construct the database.

[0154] In some embodiments, in step S320, the method for obtaining the mass spectrum of the positive sample to be tested includes:

[0155] Perform mass spectrometry identification on the positive sample to be tested, and collect the mass spectrum of the positive sample to be tested in advance;

[0156] According to the database, identifying the characteristic peaks of non-pathogenic bacteria proteins in the mass spectrum of the positive sample to be tested collected in advance, and removing the characteristic peaks of non-pathogenic bacteria proteins to obtain a processed mass spectrum of the positive sample to be tested;

[0157] The processed mass spectrum of the positive sample to be tested is homogenized to obtain a homogenized mass spectrum of the positive sample to be tested;

[0158] In the mass spectrum of the positive sample to be tested after the normalization, if the number of ion peaks with a relative signal intensity > 2% is less than a preset number, the laser intensity parameter of the mass spectrum is adjusted until the number of ion peaks with a relative signal intensity > 2% is not less than a preset number, or until the laser intensity parameter of the mass spectrum reaches a laser intensity threshold;

[0159] Under the adjusted laser intensity parameters, the mass spectrum of the positive sample to be tested is reacquired.

[0160] Specifically, when the blood culture specimen is positive, the specimen is taken out from the blood culture instrument and pre-treated using the mass spectrometry system blood culture positive sample pretreatment kit. After treatment, the positive specimen to be tested is spotted on a stainless steel target plate, covered with a matrix, and dried before being put on the machine. In the mass spectrometry identification software Ex-accuspec, select to enter the blood culture positive sample module, select the sample information, and obtain the ion peak signal of the positive sample to be tested. Collect 50 shots in advance, and the mass spectrometry identification software will convert the collected signal into a spectrum in real time to obtain a mass spectrum of the positive sample to be tested collected in advance. Compare the mass spectrum of the positive sample to be tested collected in advance with the spectrum corresponding to the characteristic peak of the non-pathogenic protein in the database, identify the characteristic peak of the non-pathogenic protein in the mass spectrum of the positive sample to be tested collected in advance, and remove it to obtain the mass spectrum of the positive sample to be tested after treatment. The mass spectrum of the positive sample to be tested after treatment is homogenized to obtain the homogenized mass spectrum of the positive sample to be tested. After homogenization, the relative signal intensity of the ion peak is between 0-1. In the mass spectrum of the positive sample to be tested after homogenization, it is determined whether the number of ion peaks with relative signal intensity>2% reaches a preset number, and the laser intensity parameters of the mass spectrum in the subsequent acquisition step are dynamically adjusted.

[0161] Exemplarily, when the relative signal intensity >2% after deducting the characteristic peaks of non-pathogenic bacteria proteins is less than 10, increase the laser intensity. The initial laser intensity is 7%, and the step size is adjusted to a gradient of 0.5%. Each time the laser intensity is adjusted, 50 shots are collected until the relative signal intensity >2% characteristic peaks are greater than 10, or the laser intensity reaches 15%. In this application, 10 is used as the preset number, and those skilled in the art can also set it to other values ​​according to actual needs, such as 12, 15, etc. The signal intensity threshold is exemplified by 2%, and can also be set to other values, such as 1.5%, 2.5%, etc. How to adjust the laser parameters can also be set to other values ​​according to actual needs.

[0162] The normalization operation refers to first obtaining the ion peak with the largest intensity in the mass spectrum of the positive sample to be tested, setting the intensity of the ion peak with the largest intensity in the mass spectrum of the positive sample to be tested to 1, and dividing the intensity of the remaining ion peaks by the intensity of the ion peak with the largest intensity.

[0163] Under the adjusted laser intensity parameters, the spectrum is collected continuously. A single collection of 50 shots needs to meet the spectrum standard, and the upper limit is 10 times, until four qualified spectra that pass the standard are collected, and all qualified collected spectra are accumulated to generate a cumulative spectrum, with a total of 200 shots. If a qualified spectrum cannot be collected after ten acquisitions, the ten signals are accumulated to generate a cumulative spectrum, that is, the mass spectrum of the positive sample to be tested is obtained.

[0164] In an embodiment of the present application, before database comparison, the characteristic peaks of non-pathogenic bacteria proteins in the mass spectrum of the pre-collected positive sample to be tested are first identified and removed, and then the laser intensity is compensated through dynamic laser adjustment technology to increase the peak intensity of the characteristic protein peak, thereby improving the identification success rate of blood culture positive samples.

[0165] In some embodiments, in step S330, the mass spectrum of the positive sample to be tested is preprocessed, and the characteristic peaks of non-pathogenic bacteria proteins are identified according to the constructed database to obtain the preprocessed mass spectrum of the positive sample to be tested, including:

[0166] Performing a first homogenization on the mass spectrum of the positive sample to be tested to obtain a homogenized mass spectrum of the positive sample to be tested;

[0167] According to the constructed database, the characteristic peaks of non-pathogenic bacteria proteins in the homogenized mass spectrum of the positive sample to be tested are identified, and the characteristic peaks of non-pathogenic bacteria proteins are removed to obtain a processed mass spectrum of the positive sample to be tested;

[0168] The treated mass spectrum of the positive sample to be tested is homogenized for the second time to obtain the pre-treated mass spectrum of the positive sample to be tested.

[0169] Specifically, before the mass spectrum of the positive sample to be tested is compared with the database, the mass spectrum of the positive sample to be tested is processed as follows: the mass spectrum of the positive sample to be tested is first homogenized, and then the identified non-pathogenic protein characteristic peaks are removed (the identification tolerance of the non-pathogenic protein peak is ±1000ppm), and then the treated mass spectrum of the positive sample to be tested is homogenized for the second time. The second homogenization can make more ion peaks appear in the obtained mass spectrum, which is convenient for the subsequent identification of the positive microorganisms to be tested and improves the identification success rate. Among them, the specific operations of the first homogenization and the second homogenization are as described in the above-mentioned homogenization method, and this application will not repeat them one by one.

[0170] Exemplarily, the mass spectrum of the positive sample to be tested is converted into a bar graph, and the intensity of the peak with the highest intensity, such as 7565.2, is set to 1, and the intensities of the remaining peaks are homogenized. Then, the characteristic peaks of non-pathogenic bacteria proteins in the blood culture background are identified, such as 15127, 7565.2, 5044.1, etc., and these peaks are deleted. Finally, the intensity of the peak with the highest intensity among the remaining peaks, such as 3678.1, is set to 1, and the remaining peak intensities are subjected to secondary homogenization. The secondary homogenized spectrum includes peak position and intensity information for spectrum comparison.

[0171] In some embodiments, in step S340, the ion peaks in the mass spectrum of the pre-processed positive sample to be tested are compared with the conservative characteristic peaks and exclusive characteristic peaks of the positive microorganisms in the database to determine the species of the positive sample to be tested, including:

[0172] First, a conventional matching algorithm is used to compare the ion peaks in the mass spectrum of the pre-treated positive sample to be tested with the conservative characteristic peaks of the positive microorganisms in the database to preliminarily determine the species of the positive sample to be tested;

[0173] Then, according to the correction rules set in the database, the ion peaks in the mass spectrum of the pre-processed positive sample to be tested are compared with the exclusive characteristic peaks of the positive microorganisms in the database, and the species of the positive sample to be tested is finally determined.

[0174] Specifically, first obtain several (such as the top ten) matching results of the positive sample to be tested through conventional matching. The conventional matching algorithm is: 1) rapid initial screening, preliminarily locking the positive sample to be tested into several possible genera or species, using the highest intensity n peaks of the positive sample to be tested in the initial screening, matching with the characteristic peaks of each genus or species or complex group in the database, and quickly sorting by the characteristic peak coverage, locking the results into several genera or species or complex groups with high ranking; 2) for several genera or species or complex groups with high ranking obtained in the initial screening, fine matching and scoring are performed, involving three aspects, ion peaks that the positive sample to be tested does not have but the database has, ion peaks that the positive sample to be tested matches with the database, and ion peaks that the positive sample to be tested has but the database does not have. From these three aspects, the ion peaks in the mass spectrum of the pretreated positive sample to be tested are compared with the ion peaks in the database to score, and several matching results with high scores are obtained. It should be noted that the ion peaks in the database here refer to the conservative characteristic peaks in the database, and can also be all characteristic peaks in the database, such as exclusive characteristic peaks and conservative characteristic peaks and other characteristic peaks.

[0175] Then, according to the correction rules set in the database, the ion peaks in the mass spectrum of the pre-processed positive sample to be tested are compared with the exclusive characteristic peaks of the positive microorganisms in the database, as follows:

[0176] If the positive microorganism has a certain exclusive characteristic peak, the microorganism to be tested also has an ion peak at the peak position corresponding to the corresponding exclusive characteristic peak, and the intensity of the ion peak is not less than the fourth intensity threshold, then the corrected score Z of the corresponding ion peak of the microorganism to be tested is 修正 =Z 得分 +ω·Z 得分 ;

[0177] If the positive microorganism has a certain exclusive characteristic peak, and the tested microorganism does not have an ion peak at the peak position corresponding to the corresponding exclusive characteristic peak, then the corrected score Z of the corresponding ion peak of the tested microorganism is 修正 =Z 得分 -ω·Z 得分 Among them, Z 得分 is the score value of the ion peak corresponding to the microorganism to be tested; ω is the weight value corresponding to the exclusive characteristic peak.

[0178] According to the above correction rules, the scores of several matching results with high scores are corrected to obtain the corrected scores of several matching results, and the matching result with the highest corrected score is used as the final identification result of the positive microorganism to be tested. In the present application, by using the scores of several microorganisms with high scores, and using the correction rules established in advance based on the matching of the positive microorganism to be tested with the exclusive characteristic peaks in the database, the scores of several microorganisms with high scores are corrected, and the unique characteristics of the positive blood culture samples can be scored and optimized to increase the accuracy of identification.

[0179] In the fourth aspect of the embodiments of the present application, Figure 6 As shown, a microorganism identification system 400 is provided, and the identification system 400 includes:

[0180] A database construction module 410 is used to construct a database for microbial identification;

[0181] The test sample acquisition module 420 is used to obtain a mass spectrum of a positive sample to be tested;

[0182] The preprocessing module 430 is used to preprocess the mass spectrum of the positive sample to be tested, and identify the characteristic peaks of non-pathogenic bacteria proteins according to the constructed database to obtain the preprocessed mass spectrum of the positive sample to be tested;

[0183] The microorganism identification module 440 is used to compare the ion peaks in the mass spectrum of the pre-processed positive sample to be tested with the conservative characteristic peaks and exclusive characteristic peaks of the positive microorganisms in the database, identify the positive sample to be tested, and determine the species of the positive sample to be tested.

[0184] Specifically, the microorganism identification system 400 provided in the embodiment of the present application is used to execute the microorganism identification method 300 provided in any embodiment of the present application. The microorganism identification system 400 provided in the embodiment of the present application can eliminate the interference of non-pathogenic bacterial proteins introduced by interfering substances such as plasma proteins, platelets, and cell fragments in the blood culture bottle, and the conservative characteristic peaks and exclusive characteristic peaks in the database can be used to further improve the accuracy of identification, shorten the identification time, improve the identification success rate, and reduce the TAT (shorten the measurement cycle) of bloodstream infection diagnosis.

[0185] It should be noted that the database construction module 410 may be the device 200 for constructing a database for microorganism identification provided in any embodiment of the present application.

[0186] In some implementations, the test sample acquisition module 420 is configured to:

[0187] Perform mass spectrometry identification on the positive sample to be tested, and collect the mass spectrum of the positive sample to be tested in advance;

[0188] According to the database, identifying the characteristic peaks of non-pathogenic bacteria proteins in the mass spectrum of the positive sample to be tested collected in advance, and removing the characteristic peaks of non-pathogenic bacteria proteins to obtain a processed mass spectrum of the positive sample to be tested;

[0189] The processed mass spectrum of the positive sample to be tested is homogenized to obtain a homogenized mass spectrum of the positive sample to be tested;

[0190] In the mass spectrum of the positive sample to be tested after the normalization, if the number of ion peaks with a relative signal intensity > 2% is less than a preset number, the laser intensity parameter of the mass spectrum is adjusted until the number of ion peaks with a relative signal intensity > 2% is not less than a preset number, or until the laser intensity parameter of the mass spectrum reaches a laser intensity threshold;

[0191] Under the adjusted laser intensity parameters, the mass spectrum of the positive sample to be tested is reacquired.

[0192] In some embodiments, the pre-processing module 430 is configured to:

[0193] Performing a first homogenization on the mass spectrum of the positive sample to be tested to obtain a homogenized mass spectrum of the positive sample to be tested;

[0194] According to the constructed database, the characteristic peaks of non-pathogenic bacteria proteins in the homogenized mass spectrum of the positive sample to be tested are identified, and the characteristic peaks of non-pathogenic bacteria proteins are removed to obtain a processed mass spectrum of the positive sample to be tested;

[0195] The treated mass spectrum of the positive sample to be tested is homogenized for the second time to obtain the pre-treated mass spectrum of the positive sample to be tested.

[0196] In some embodiments, the microorganism identification module 440 is configured to:

[0197] First, a conventional matching algorithm is used to compare the ion peaks in the mass spectrum of the pre-treated positive sample to be tested with the conservative characteristic peaks of the positive microorganisms in the database to preliminarily determine the species of the positive sample to be tested;

[0198] Then, according to the correction rules set in the database, the ion peaks in the mass spectrum of the pre-processed positive sample to be tested are compared with the exclusive characteristic peaks of the positive microorganisms in the database, and the species of the positive sample to be tested is finally determined.

[0199] It should be noted that the method and device for constructing a database for microorganism identification, the identification method and system provided in any embodiment of the present application are suitable for identifying microorganisms in blood.

[0200] Figure 8 A schematic structural diagram of an electronic device provided according to an embodiment of the present application is shown.

[0201] like Figure 8 As shown, as another aspect, the present application also provides an electronic device 500, including one or more central processing units (CPU) 501, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 502 or the program loaded from the storage part 508 to the random access memory (RAM) 503. In the RAM 503, various programs and data required for system operation are also stored. The CPU 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0202] The following components are connected to the I / O interface 305: an input section 506 including a keyboard, a mouse, etc.; an output section 507 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN card, a modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to the I / O interface 505 as needed. A removable medium 511, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 510 as needed, so that a computer program read therefrom is installed into the storage section 508 as needed.

[0203] In particular, according to the embodiments of the present disclosure, the above reference Figure 1 and Figure 6 The described process can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program tangibly contained on a machine-readable medium, and the computer program includes program code for executing a method for constructing a database for microbial identification. In such an embodiment, the computer program can be downloaded and installed from a network through the communication portion 509, and / or installed from a removable medium 511.

[0204] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a different order from the order marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0205] As another aspect, the present application also provides a computer-readable storage medium, which may be a computer-readable storage medium included in the device described in the above embodiment; or a computer-readable storage medium that exists independently and is not assembled into the device. The computer-readable storage medium stores one or more programs, and the programs are used by one or more processors to execute the method for constructing a microorganism identification database described in the present application.

[0206] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present invention. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be realized by a dedicated hardware-based system that performs a specified function or operation, or can be realized by a combination of dedicated hardware and computer instructions.

[0207] The units or modules involved in the embodiments described in the present application may be implemented by software or by hardware. The units or modules described may also be arranged in a processor. For example, each of the units may be a software program arranged in a computer or a mobile smart device, or may be a separately configured hardware device. The names of these units or modules do not, in some cases, constitute limitations on the units or modules themselves.

[0208] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A method for constructing a database for microbial identification, characterized in that: The construction method comprises: Collect blood culture positive and blood culture negative sample sets; The blood culture positive sample set and the blood culture negative sample set are processed respectively by using a microbial enrichment method to obtain a positive microbial set and a processed negative sample set; Using mass spectrometry to perform mass spectrometry identification on the positive microorganism set and the processed negative sample set, respectively, to obtain a mass spectrum of the positive sample set and a mass spectrum of the negative sample set; Acquire non-pathogenic bacteria protein characteristic peaks according to the mass spectrum of the negative sample set; The conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism are obtained according to the mass spectrum of the positive sample set and the standard culture reference spectrum.

2. The method for constructing a database for microbial identification according to claim 1, characterized in that: The processed negative sample set is subjected to mass spectrometry identification to obtain a mass spectrum of the negative sample set, including: The processed negative sample set includes M negative samples, and each negative sample is sampled at least N times to obtain M×N negative sample mass spectra, that is, the negative sample set mass spectra include M×N negative sample mass spectra; wherein M and N are natural numbers greater than or equal to 1 respectively.

3. The method for constructing a database for microbial identification according to claim 2, characterized in that: Obtaining non-pathogenic bacterial protein characteristic peaks according to the mass spectrum of the negative sample set includes: Obtain the ion peak intensity corresponding to each mass-to-charge ratio from the mass spectrum of the negative sample set, record the number of times the same mass-to-charge ratio appears in the mass spectrum of the negative sample set, and calculate the average intensity of the ion peak corresponding to the same mass-to-charge ratio; If in the mass spectrum of the negative sample set, there is an ion peak corresponding to the same mass-to-charge ratio, the average intensity of which is not less than the first intensity threshold, and the mass-to-charge ratio appears at least once in the N mass spectra corresponding to each negative sample, and the number of appearances m in the mass spectrum of the negative sample set is: M≤m≤M×N; then the ion peak corresponding to the mass-to-charge ratio is a characteristic peak of non-pathogenic bacteria protein, and all characteristic peaks of non-pathogenic bacteria proteins of the negative samples are obtained.

4. The method for constructing a microorganism identification database according to any one of claims 1 to 3, characterized in that: Performing mass spectrometry identification on the positive microorganism set by mass spectrometry to obtain a mass spectrum of the positive sample set; The positive microorganism set includes G positive samples, each positive sample includes at least Q strains, and each strain is spotted at least B times; wherein G, Q, and B are natural numbers greater than or equal to 1 respectively; Then each positive sample corresponds to Q×B positive sample mass spectra, and G positive samples correspond to G×Q×B positive sample mass spectra, that is, the mass spectrum of the positive sample set includes G×Q×B positive sample mass spectra.

5. The method for constructing a database for microbial identification according to claim 4, characterized in that: Obtain the conservative characteristic peaks of each positive microorganism according to the mass spectrum of the positive sample set and the standard culture reference spectrum, including: From the Q×B positive sample mass spectra corresponding to each positive sample, obtain the ion peak intensity corresponding to each mass-to-charge ratio, and record the number of times n that the same mass-to-charge ratio appears in the Q×B positive sample mass spectra, and calculate the average intensity of the ion peak corresponding to the same mass-to-charge ratio; The mass spectra of Q×B positive samples were compared with the spectra of the corresponding positive samples in the standard culture reference spectrum, and the ion peaks appearing at the same peak positions in the mass spectra of Q×B positive samples and the spectra of the corresponding positive samples in the standard culture reference spectrum were defined as the conservative characteristic peaks of the positive microorganisms, and all the conservative characteristic peaks of the G positive microorganisms were obtained in sequence.

6. The method for constructing a database for microorganism identification according to claim 5, characterized in that: The ion peaks that appear at the same peak position in the mass spectra of Q×B positive samples and the spectra of the corresponding positive samples in the standard culture reference spectrum are defined as the conservative characteristic peaks of the positive microorganism, including: If the mass spectra of Q×B positive samples and the spectra of the corresponding positive samples in the standard culture reference spectrum have the same mass-to-charge ratio, the following conditions are met: The average intensity of the ion peaks of the mass-to-charge ratio in the mass spectra of Q×B positive samples and the spectra of the standard culture reference spectra corresponding to the positive samples is not less than the second intensity threshold, and the number of times n that the mass-to-charge ratio appears in the mass spectra of Q×B positive samples is: The number of occurrences in the spectra corresponding to positive samples in the standard culture reference spectrum is not less than two-thirds of the total number of spectra corresponding to positive samples in the standard culture reference spectrum; The ion peak corresponding to the mass-to-charge ratio that meets the above conditions is taken as the conservative characteristic peak corresponding to the positive microorganism.

7. The method for constructing a database for microorganism identification according to claim 5 or 6, characterized in that: Obtaining the exclusive characteristic peak of each positive microorganism according to the mass spectrum of the positive sample set and the standard culture reference spectrum, including: The non-pathogen protein characteristic peaks and conservative characteristic peaks in the Q×B positive sample mass spectra corresponding to each positive sample are removed to obtain the processed Q×B positive sample mass spectra; The mass spectra of the Q×B positive samples after the treatment are compared with the spectra of the corresponding positive samples in the standard culture reference spectrum. If there is an ion peak at a certain peak position in the mass spectrum of the Q×B positive samples after the treatment, and there is no ion peak at the corresponding peak position in the spectrum of the corresponding positive sample in the standard culture reference spectrum, then the ion peak corresponding to the peak position is the exclusive characteristic peak of the positive microorganism, and all the exclusive characteristic peaks of the G positive microorganisms are obtained in sequence.

8. The method for constructing a database for microorganism identification according to claim 7, characterized in that: If there is an ion peak at a certain peak position in the mass spectrum of the processed Q×B positive samples, and there is no ion peak at the corresponding peak position in the spectrum of the corresponding positive sample in the standard culture reference spectrum, then the ion peak corresponding to the peak position is the exclusive characteristic peak of the positive microorganism, including: If the mass spectra of Q×B positive samples after processing and the spectra of the corresponding positive samples in the standard culture reference spectrum have the same mass-to-charge ratio, the following conditions are met: The average intensity of the ion peaks of the mass-to-charge ratio in the mass spectra of the Q×B positive samples after processing and the spectra of the corresponding positive samples in the standard culture reference spectrum is not less than the third intensity threshold, and the number of occurrences of the mass-to-charge ratio in the mass spectra of the Q×B positive samples is n: The number of occurrences in the spectra corresponding to positive samples in the standard culture reference spectrum is not greater than one third of the total number of spectra corresponding to positive samples in the standard culture reference spectrum; The ion peak corresponding to the mass-to-charge ratio that meets the above conditions is taken as the exclusive characteristic peak of the corresponding positive microorganism.

9. The method for constructing a microorganism identification database according to claim 7 or 8, characterized in that: The method further comprises: Weight values ​​are set for all exclusive characteristic peaks of the G positive microorganisms, and correction rules are set according to the weight values ​​corresponding to the exclusive characteristic peaks. The scores of the corresponding ion peaks of the microorganisms to be tested are corrected using the correction rules to obtain the corrected scores of the corresponding ion peaks of the microorganisms to be tested.

10. The method for constructing a database for microorganism identification according to claim 9, characterized in that: The correction rules are: If the positive microorganism has a certain exclusive characteristic peak, the microorganism to be tested also has an ion peak at the peak position corresponding to the corresponding exclusive characteristic peak, and the intensity of the ion peak is not less than the fourth intensity threshold, then the corrected score Z of the corresponding ion peak of the microorganism to be tested is 修正 =Z 得分 +ω·Z 得分 ; If the positive microorganism has a certain exclusive characteristic peak, and the tested microorganism does not have an ion peak at the peak position corresponding to the corresponding exclusive characteristic peak, then the corrected score Z of the corresponding ion peak of the tested microorganism is 修正 =Z 得分 -ω·Z 得分 ; Among them, Z 得分 is the score value of the ion peak corresponding to the microorganism to be tested; ω is the weight value corresponding to the exclusive characteristic peak.

11. A device for constructing a database for microorganism identification, characterized in that: The construction device comprises: A collection module, used for collecting a blood culture positive sample set and a blood culture negative sample set; A processing module, used to process the blood culture positive sample set and the blood culture negative sample set respectively by using a microorganism enrichment method to obtain a positive microorganism set and a processed negative sample set; A mass spectrometry identification module, used to perform mass spectrometry identification on the positive microorganism set and the processed negative sample set respectively by mass spectrometry to obtain a mass spectrum of the positive sample set and a mass spectrum of the negative sample set; A first acquisition module is used to acquire non-pathogenic bacteria protein characteristic peaks according to the mass spectrum of the negative sample set; The second acquisition module is used to acquire the conservative characteristic peaks and exclusive characteristic peaks of each positive microorganism according to the mass spectrum of the positive sample set and the standard culture reference spectrum.

12. A method for identifying microorganisms, characterized in that: The identification method comprises: Constructing a database, wherein the database includes characteristic peaks of non-pathogenic bacteria proteins of negative samples and conservative characteristic peaks and exclusive characteristic peaks corresponding to at least one positive microorganism; Obtaining a mass spectrum of a positive sample to be tested; Preprocessing the mass spectrum of the positive sample to be tested, and identifying the characteristic peaks of non-pathogenic bacteria proteins according to the constructed database to obtain the preprocessed mass spectrum of the positive sample to be tested; The ion peaks in the mass spectrum of the pre-treated positive sample to be tested are compared with the conservative characteristic peaks and exclusive characteristic peaks of the positive microorganisms in the database, the positive sample to be tested is identified, and the species of the positive sample to be tested is determined.

13. The method for identifying microorganisms according to claim 12, characterized in that: The database is constructed using the method for constructing a microorganism identification database according to any one of claims 1 to 10.

14. The method for identifying microorganisms according to claim 12, characterized in that: The method for obtaining the mass spectrum of the positive sample to be tested includes: Perform mass spectrometry identification on the positive sample to be tested, and collect the mass spectrum of the positive sample to be tested in advance; According to the database, identifying the characteristic peaks of non-pathogenic bacteria proteins in the mass spectrum of the positive sample to be tested collected in advance, and removing the characteristic peaks of non-pathogenic bacteria proteins to obtain a processed mass spectrum of the positive sample to be tested; The processed mass spectrum of the positive sample to be tested is homogenized to obtain a homogenized mass spectrum of the positive sample to be tested; In the mass spectrum of the positive sample to be tested after the normalization, if the number of ion peaks with a relative signal intensity > 2% is less than a preset number, the laser intensity parameter of the mass spectrum is adjusted until the number of ion peaks with a relative signal intensity > 2% is not less than a preset number, or until the laser intensity parameter of the mass spectrum reaches a laser intensity threshold; Under the adjusted laser intensity parameters, the mass spectrum of the positive sample to be tested is reacquired.

15. The method for identifying microorganisms according to claim 14, characterized in that: Preprocessing the mass spectrum of the positive sample to be tested, and identifying the characteristic peaks of non-pathogenic bacteria proteins according to the constructed database to obtain the preprocessed mass spectrum of the positive sample to be tested, including: Performing a first homogenization on the mass spectrum of the positive sample to be tested to obtain a homogenized mass spectrum of the positive sample to be tested; According to the constructed database, the characteristic peaks of non-pathogenic bacteria proteins in the homogenized mass spectrum of the positive sample to be tested are identified, and the characteristic peaks of non-pathogenic bacteria proteins are removed to obtain a processed mass spectrum of the positive sample to be tested; The treated mass spectrum of the positive sample to be tested is homogenized for the second time to obtain the pre-treated mass spectrum of the positive sample to be tested.

16. The method for identifying a microorganism according to any one of claims 12 to 15, characterized in that: Comparing the ion peaks in the mass spectrum of the pre-treated positive sample to be tested with the conservative characteristic peaks and exclusive characteristic peaks of the positive microorganisms in the database to determine the species of the positive sample to be tested, including: First, a conventional matching algorithm is used to compare the ion peaks in the mass spectrum of the pre-treated positive sample to be tested with the conservative characteristic peaks of the positive microorganisms in the database to preliminarily determine the species of the positive sample to be tested; Then, according to the correction rules set in the database, the ion peaks in the mass spectrum of the pre-processed positive sample to be tested are compared with the exclusive characteristic peaks of the positive microorganisms in the database, and the species of the positive sample to be tested is finally determined.

17. A microorganism identification system, characterized in that: The identification system comprises: A database construction module is used to construct a database for microbial identification; A test sample acquisition module is used to obtain a mass spectrum of a positive sample to be tested; A preprocessing module is used to preprocess the mass spectrum of the positive sample to be tested, and identify the characteristic peaks of non-pathogenic bacteria proteins according to the constructed database to obtain the preprocessed mass spectrum of the positive sample to be tested; The microorganism identification module is used to compare the ion peaks in the mass spectrum of the pre-treated positive sample to be tested with the conservative characteristic peaks and exclusive characteristic peaks of the positive microorganisms in the database, identify the positive sample to be tested, and determine the species of the positive sample to be tested.

18. An electronic device, characterized in that: include: one or more processors; a memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors execute the method for constructing a microorganism identification database as described in any one of claims 1 to 10, or execute the method for identifying a microorganism as described in any one of claims 12 to 16.

19. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the computer program implements the method for constructing a microorganism identification database according to any one of claims 1 to 11, or executes the method for identifying a microorganism according to any one of claims 12 to 16.

Images