A system and method for rapid detection of sepsis pathogen-host integration

Abstract

The application provides a sepsis pathogen and host integrated rapid detection system and method, the system comprises a whole blood sampling and plasma separation unit, a nanobody magnetic bead immune enrichment unit, a host and pathogen marker immune detection unit, an enriched pathogen lysis and isothermal nucleic acid amplification unit, a signal reading unit and a combined risk interpretation unit. The application connects low load pathogen capture, host reaction detection, pathogen nucleic acid confirmation and clinical risk interpretation into the same closed loop process, so that the detection result has both pathogenic basis and host reaction support, thereby improving the sensitivity, specificity and clinical interpretability of early sepsis detection.

Description

Technical Field

[0001] This invention relates to the fields of in vitro diagnostics, microfluidic detection, immune enrichment, isothermal nucleic acid amplification, and clinical infection risk assessment, specifically to a rapid detection system and method for sepsis pathogens and hosts. Background Technology

[0002] Sepsis is a life-threatening organ dysfunction caused by a dysregulation of the host response to infection. Its disease progresses rapidly, and early identification and timely anti-infective treatment are crucial for reducing mortality. Current clinical diagnosis mainly relies on blood cultures, single inflammatory marker detection, nucleic acid testing, or immunochromatographic analysis, but these methods still have significant limitations in the rapid early identification of sepsis.

[0003] While blood cultures can confirm viable bacterial infections and perform drug sensitivity analysis, positive results typically take 24 to 72 hours, making it difficult to meet the rapid decision-making needs of emergency and critical care settings. Blood cultures are also susceptible to the effects of antibiotic use, insufficient blood volume, and low bacteremia, posing a certain risk of missed detection in early sepsis patients.

[0004] While nucleic acid testing offers high analytical speed, the pathogen load in the peripheral blood of sepsis patients is typically only one to ten colony-forming units per milliliter. Conventional nucleic acid testing, without effective enrichment, often requires a high template copy number for stable detection, and human cells, hemoglobin, free nucleic acids, and amplification inhibitors in blood samples can reduce detection sensitivity. Furthermore, nucleic acid testing often struggles to distinguish between live bacteria, dead bacteria residues, and environmental contamination, leading to uncertainty in the clinical interpretation of positive results.

[0005] While simple immune testing can provide results quickly, its detection limit is usually higher than the actual pathogen concentration in the blood during early sepsis. For host biomarkers, indicators such as white blood cell count, C-reactive protein, procalcitonin, and interleukins can be affected by non-infectious inflammation, surgical trauma, tumors, or immune status; interpreting a single threshold can easily lead to false positives or false negatives.

[0006] Most existing multi-indicator combined detection products only display pathogen or host indicators side-by-side at the result level, lacking a mechanism for integrated modeling of pathogen presence evidence, pathogen activity evidence, host inflammatory response intensity, and tissue perfusion status. They also lack an engineered solution to complete sample separation, pathogen enrichment, immune detection, nucleic acid amplification, and joint interpretation within a single enclosed chip. Therefore, there is an urgent need for an integrated sepsis detection system and method capable of efficient capture under low pathogen load conditions, while simultaneously combining host response for rapid, accurate, and interpretable interpretation. Summary of the Invention

[0007] To address the aforementioned issues, this invention provides an integrated rapid detection system and method for sepsis pathogens and hosts. It utilizes nano-antibody magnetic beads to specifically pre-enrich low-load pathogens and simultaneously performs host inflammatory marker detection, pathogen marker detection, and enriched pathogen nucleic acid amplification detection within the same microfluidic chip. Furthermore, a joint interpretation model based on pathogen load and host response intensity outputs stratification results for infection risk, sepsis risk, and septic shock risk. This system is suitable for rapid detection scenarios in emergency departments, intensive care units, infectious disease departments, and bedside settings.

[0008] The specific plan is as follows:

[0009] A rapid detection system integrating sepsis pathogen and host includes a whole blood sampling and plasma separation unit, a nanobody magnetic bead immunoenrichment unit, a host and pathogen biomarker immunodetection unit, a pathogen enrichment lysis and isothermal nucleic acid amplification unit, a signal reading unit, and a combined risk assessment unit.

[0010] The whole blood sample and plasma separation unit is used to receive whole blood samples and separate plasma and fluid fraction containing intact pathogens.

[0011] Nanobody magnetic bead immunoenrichment unit for capturing and enriching pathogens in the fluid portion containing intact pathogens by superparamagnetic microbeads coupled with specific nanobodies.

[0012] The host and pathogen biomarker immunoassay unit is used to detect host biomarkers and universal pathogen biomarkers in isolated plasma.

[0013] The pathogen enrichment lysis and isothermal nucleic acid amplification unit is used to lyse and release nucleic acids from immuno-enriched pathogens and perform isothermal nucleic acid amplification.

[0014] The signal reading unit is used to read the detection signals from the immunoassay unit and the nucleic acid amplification unit;

[0015] The joint risk assessment unit is used to perform joint risk scoring based on the detection results obtained by the signal reading unit and output a report. The output risk score and report are auxiliary assessment information used by doctors to make a comprehensive judgment in conjunction with other clinical information.

[0016] Furthermore, in the whole blood sampling and plasma separation unit, after the whole blood sample enters the chip through the sample inlet, it first undergoes rapid separation of plasma and blood cells through a hydrophilic porous membrane or equivalent microstructure. The separated plasma enters the immunodetection zone for detecting host markers and universal pathogen markers. The fluid portion containing intact pathogens enters the immunoenrichment zone for subsequent magnetic bead capture. This design avoids centrifugation, pipetting, and open nucleic acid extraction steps, reducing sample loss and the risk of cross-contamination.

[0017] Furthermore, in the nanobody magnetic bead immunoenrichment unit, superparamagnetic microbeads coupled with specific nanobodies are used as capture carriers; for Escherichia coli, nanobody magnetic beads targeting the outer membrane protein OmpA are used for capture; for Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa, nanobody magnetic beads targeting high-abundance surface antigens of OmpK36, Protein A, and OprF are used to expand the capture spectrum; after the magnetic beads are fully mixed with the sample in the microfluidic channel, they are immobilized in the enrichment area under the action of an external magnetic field, and unbound human cells, free DNA, and inhibitors are discharged with the washing solution, thereby achieving pathogen concentration and background removal;

[0018] Immunoenrichment efficiency and effective enrichment fold are characterized by the following formula:

[0019]

[0020] in, Indicates pathogen capture efficiency. This indicates the concentration of pathogens in the reaction solution after enrichment. This indicates the volume of the reaction liquid after enrichment. This indicates the concentration of pathogens in the original whole blood sample. This indicates the volume of the original whole blood sample. This indicates the effective enrichment factor of the pathogen. By concentrating intact pathogens from a large volume of whole blood into a smaller volume of reaction solution and simultaneously removing a large amount of human background, this invention can increase the effective template concentration for subsequent nucleic acid amplification to a range that can be stably detected.

[0021] Furthermore, the host and pathogen marker immune detection unit simultaneously detects four types of host markers and two types of universal pathogen markers in the plasma pathway. The four types of host markers include interleukin-6, procalcitonin, soluble CD14 subtype, and lactate. The two types of pathogen markers include lipopolysaccharide-binding protein-related signals and lipoteichoic acid-related signals. Interleukin-6 is used to reflect the early inflammatory initiation state, procalcitonin is used to help determine the bacterial infection tendency, soluble CD14 subtype is used to reflect the sepsis-related monocyte-macrophage activation state, and lactate is used to indicate insufficient tissue perfusion and the risk of shock. The lipopolysaccharide-binding protein-related signal is used to indicate evidence of Gram-negative bacterial infection, and the lipoteichoic acid-related signal is used to indicate evidence of Gram-positive bacterial infection.

[0022] The detection reagents for each biomarker are pre-encapsulated in lyophilized form within the immunoassay zone. After plasma flows through the corresponding reaction chamber, the biomarker forms a detectable complex with the fluorescently labeled antibody or equivalent signal probe. The signal reading unit calculates the concentration of each biomarker based on the fluorescence intensity, internal reference signal, and calibration curve. This detection result is not used alone as a final diagnostic conclusion, but rather as input into a joint interpretation model for both host response intensity and general pathogen evidence.

[0023] Furthermore, in the pathogen enrichment lysis and isothermal nucleic acid amplification unit, the immunoenriched magnetic bead-pathogen complex enters the lysis reaction zone, where pathogen nucleic acid is released through chemical lysis, thermal lysis, or enzymatic lysis. The released nucleic acid then enters the isothermal amplification zone for recombinase polymerase amplification or an equivalent isothermal amplification reaction. The amplification primers are designed to target conserved sequences of the pathogen and are consistent with the pathogen category corresponding to the immunoenrichment. Since the upstream enrichment target is mainly intact pathogens, this invention can reduce the interference of free nucleic acid, dead bacterial fragments, and environmental contamination on positive nucleic acid results.

[0024] Furthermore, the joint risk assessment unit does not directly determine sepsis using a single biomarker threshold, but instead integrates pathogen evidence, host inflammatory response, and lactate perfusion risk; based on nucleic acid amplification results, universal pathogen biomarker results, and host biomarker concentrations, a pathogen-host joint risk score is constructed.

[0025]

[0026] in, This represents the combined risk score for sepsis, with a value ranging from 0 to 1. This represents the Sigmoid normalization function; Represents the model bias term; to These represent the weighting coefficients of each input indicator; This represents the evidence value for pathogen nucleic acid detection, with 1 for a positive result and 0 for a negative result, or it can be converted into a continuous evidence value based on the amplification time. The evidence value for universal pathogen markers is obtained by combining lipopolysaccharide-binding protein-related signals and lipoteichoic acid-related signals. This indicates the concentration of interleukin-6 detected. This indicates the reference threshold for interleukin-6; This indicates the detected concentration of procalcitonin. Indicates the reference threshold for procalcitonin; This indicates the detection concentration of soluble CD14 subtypes. Indicates the reference threshold for soluble CD14 subtypes; This indicates the concentration of lactic acid detected. Indicates the lactate reference threshold; the joint risk score As an intermediate quantitative indicator, this score is provided for clinicians to make a comprehensive judgment based on the patient's clinical manifestations. It does not constitute a direct diagnostic conclusion.

[0027] Furthermore, the joint risk assessment unit outputs results according to the following rules:

[0028] When at least one of the pathogen nucleic acid test or universal pathogen marker is positive, and the host inflammatory marker reaches the set response level, the system outputs a high risk of infection or a high risk of sepsis. When the combined risk score is high and lactate exceeds the perfusion risk threshold, the system further outputs a high risk of septic shock. When the pathogen evidence is weak and the host response is normal or low, the system marks the result as suspected colonization, contamination, or requiring verification, to avoid misjudgment based solely on a weak positive pathogen result.

[0029] A method for rapid detection of sepsis pathogen and host in an integrated manner, comprising the following steps:

[0030] S1. Whole blood sample injection and plasma separation: The whole blood sample is injected into the whole blood sample injection and plasma separation unit to separate plasma and fluid fraction containing intact pathogens.

[0031] S2, Immune detection: The plasma obtained in step S1 is introduced into the host and pathogen marker immune detection unit to detect host markers and universal pathogen markers;

[0032] S3, Immunoenrichment: The fluid portion containing intact pathogens obtained in step S1 is introduced into the nanobody magnetic bead immunoenrichment unit, and the pathogens are captured and enriched by superparamagnetic microbeads coupled with specific nanobodies.

[0033] S4, Lysis and Nucleic Acid Amplification: The immuno-enriched magnetic bead-pathogen complex is introduced into the enriched pathogen lysis and isothermal nucleic acid amplification unit to release pathogen nucleic acid and perform isothermal nucleic acid amplification.

[0034] S5. Signal reading: Read the detection signals from steps S2 and S4 through the signal reading unit;

[0035] S6. Combined Risk Interpretation: Input the read signals into the combined risk interpretation unit, calculate the risk score and output a report, which is used by clinicians to make a comprehensive judgment based on the patient's clinical signs and other laboratory test information.

[0036] Through the above technical solution, the present invention connects low-load pathogen capture, host response detection, pathogen nucleic acid confirmation, and clinical risk assessment into a closed-loop process, so that the detection results have both etiological basis and host response support, thereby improving the sensitivity, specificity, and clinical interpretability of early sepsis detection.

[0037] The beneficial effects of this invention are as follows:

[0038] 1. This invention uses nano-antibody magnetic beads to pre-enrich intact pathogens, so that low-load pathogens are concentrated before entering nucleic acid amplification, and human cells, free DNA and blood amplification inhibitors are removed simultaneously, thereby improving the detection sensitivity in the early sepsis hypobacteremia state.

[0039] 2. This invention integrates pathogen nucleic acid detection, universal pathogen biomarker detection, and host inflammatory response detection into the same closed microfluidic chip, avoiding sample loss and contamination risks caused by multiple opening of the cap, centrifugation, pipetting, and cross-instrument operations in traditional processes, which is conducive to achieving rapid bedside testing and rapid emergency decision-making.

[0040] 3. This invention employs a pathogen-host joint risk scoring model, rather than relying on a single pathogen positivity or a single inflammatory marker exceeding a threshold as the basis for diagnosis. This model can establish a correspondence between pathogen evidence and host response, more rationally distinguishing between suspected contamination, colonization, dead bacterial residue, and non-infectious inflammation, thereby improving the clinical interpretability of test results.

[0041] 4. This invention supports expanded detection of common sepsis pathogens such as Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa within the same technical framework. By replacing or adding different nanobody magnetic beads and corresponding nucleic acid primer probes, the detection coverage can be expanded without changing the overall chip structure and interpretation logic.

[0042] 5. This invention combines host indicators such as interleukin-6, procalcitonin, soluble CD14 subtype and lactate with lipopolysaccharide-binding protein-related signals, lipoteichoic acid-related signals and pathogen nucleic acid results. It can simultaneously reflect early inflammation initiation, bacterial infection tendency, sepsis-related immune activation and tissue perfusion risk, and provide stratified output of infection risk, sepsis risk and septic shock risk.

[0043] 6. The detection process of this invention is short, highly automated, and requires minimal operator intervention, making it suitable for scenarios requiring rapid assessment of infection risk, such as emergency rooms, intensive care units, and primary healthcare institutions. Compared to traditional blood cultures, this invention can provide dual evidence of pathogen and host in a shorter time; compared to simple nucleic acid detection or simple immunoassay, this invention offers better overall performance in terms of sensitivity, specificity, and completeness of clinical interpretation. Attached Figure Description

[0044] Figure 1 This is a flowchart of the method of the present invention.

[0045] Figure 2 This is a system architecture diagram of the present invention. Detailed Implementation

[0046] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0047] As shown in the figure, this invention provides an integrated rapid detection method for sepsis pathogens and hosts, based on a system comprising a whole blood sampling and plasma separation unit, a nanobody magnetic bead immunoenrichment unit, a host and pathogen biomarker immunodetection unit, a pathogen enrichment lysis and isothermal nucleic acid amplification unit, a signal reading unit, and a combined risk assessment unit. Taking the detection process of a whole blood sample suspected of causing sepsis in the emergency department as an example, the method includes the following steps:

[0048] First, one milliliter of anticoagulated whole blood sample is collected from a suspected sepsis patient and added to the inlet of a disposable, closed microfluidic chip. The chip contains a pre-installed hydrophilic plasma separation membrane, nano-antibody magnetic beads, immunoassay reagents, pathogen lysis reagents, isothermal amplification reagents, primers and probes, and internal control materials. After the chip is inserted into the matching detector, the instrument automatically drives the sample to flow along a preset path and controls the temperature of the immunoassay zone and the isothermal amplification zone separately.

[0049] After whole blood enters the chip, the plasma separation area obtains plasma components for immunoassay within minutes. The plasma first flows into the host and pathogen marker immunoassay unit, where it reacts with detection reagents corresponding to interleukin-6, procalcitonin, soluble CD14 subtypes, lactate, lipopolysaccharide-binding protein-related signals, and lipoteichoic acid-related signals in multiple parallel reaction chambers. After the detector reads the fluorescence signals from each reaction chamber, it converts them into the corresponding indicator concentrations based on the chip's built-in standard curve and internal reference calibration results, and caches the results in the joint risk interpretation unit.

[0050] Simultaneously with plasma testing, another portion of the sample fluid enters the nanobody magnetic bead immunoenrichment unit. Taking E. coli detection as an example, superparamagnetic microbeads conjugated with OmpA nanobodies are pre-placed within the chip. The sample and magnetic beads are in full contact within a serpentine mixing channel, where intact E. coli bind to the nanobodies via their surface OmpA antigens, forming magnetic bead-pathogen complexes. Subsequently, an external magnetic field is applied by the detector to immobilize the complexes within the enrichment chambers, and unbound human cells, free DNA, and amplification inhibitors are removed using a washing solution. If the chip is configured for broad-spectrum detection, OmpK36, Protein A, and OprF nanobody magnetic beads can be pre-placed in adjacent enrichment chambers to cover common septic pathogens such as Klebsiella pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa.

[0051] After enrichment, the system follows the formula and The definition of enrichment efficiency evaluates the capture efficiency and enrichment fold during the process validation phase. In actual testing, the instrument does not need to directly output the aforementioned process parameters, but maintains a stable enrichment process by using fixed sample volumes, enrichment reaction liquid volumes, and magnetic bead dosages, ensuring that the original low-load pathogens are concentrated into a smaller reaction volume before amplification. Taking *E. coli* with one to ten colony-forming units per milliliter of whole blood as an example, after immune capture and elution, the target pathogen enters an amplification reaction system at the tens of microliter level, thereby significantly increasing the effective concentration of the amplification template.

[0052] The magnetic bead-pathogen complex then enters the lysis and isothermal nucleic acid amplification unit. After the lysis reagent releases the pathogen nucleic acid, the amplification reaction is carried out at an isothermal temperature of approximately 42 degrees Celsius. The amplification system contains primers, probes, recombinase, polymerase, and a buffer system targeting the conserved sequence of the target pathogen. The detector reads the amplification fluorescence signal in real time and determines the evidence value for pathogen nucleic acid detection based on whether the amplification curve exceeds the threshold, the amplification initiation time, and whether the internal control reaction is normal. If the internal reference fails, the system will indicate that the sample test is invalid and require a retest.

[0053] After immune and nucleic acid testing are completed, the joint risk assessment unit calls the same pathogen-host joint risk scoring model. The system then assigns pathogen nucleic acid evidence values... Evidence values ​​of common pathogen markers Interleukin-6 concentration detection Calcium-lowering procalcitonin concentration detection Detection concentration of soluble CD14 subtype Lactic acid detection concentration And its corresponding reference threshold input formula:

[0054]

[0055] The test report outputs stratified results based on a combination of joint scores and key evidence. Positive or When there is clear evidence of a pathogen, and multiple indicators such as interleukin-6, procalcitonin, and soluble CD14 subtypes exceed their corresponding thresholds, the system outputs a high risk of sepsis and suggests immediate anti-infective assessment based on clinical manifestations. When the level reaches a high-risk range and lactate concentration exceeds the tissue perfusion risk threshold, the system outputs a high risk of septic shock. When only a weak pathogen signal is present and host markers do not show a corresponding increase, the system outputs a result of suspected contamination, colonization, or low clinical relevance, and recommends verification or dynamic monitoring.

[0056] In a typical embodiment, the detection process, from sample introduction to report output, is controlled within approximately 25 minutes. This includes approximately 5 minutes for plasma separation, approximately 10 minutes for immunoassay and pathogen enrichment, approximately 10 minutes for lysis and isothermal amplification, and simultaneous signal reading and interpretation at the amplification endpoint. Since all reactions are completed within a sealed chip, operators only need to add the sample and load it onto the chip; centrifugation, nucleic acid extraction, manual transfer, and switching between multiple instruments are unnecessary.

[0057] To ensure detection reliability, the chip incorporates sample flow quality control, an internal control for the immune response, an internal control for nucleic acid amplification, and a negative background monitoring area. The sample flow quality control determines whether plasma separation and channel flow are normal; the internal control for the immune response corrects for batch-to-batch reagent differences and fluorescence drift; the internal control for nucleic acid amplification excludes amplification inhibition or reagent failure; and the negative background monitoring area identifies nonspecific adsorption and environmental contamination. The results of these quality control measures, along with the detection indicators, are fed into the reporting logic, and a valid clinical risk result is only output when the quality control is passed.

[0058] In this embodiment, the nanobody magnetic beads, universal pathogen marker detection, host marker detection, and isothermal nucleic acid amplification are all designed around the same goal of sepsis risk assessment. Immunoenrichment addresses the difficulty in detecting low-load pathogens, nucleic acid amplification confirms the pathogenic identity of the enriched sample, host markers determine whether pathogenic evidence triggers a clinically relevant host response, and lactate further indicates the risk of shock. The units are interconnected according to sample flow and interpretation logic, forming an integrated detection loop from sample entry to risk output.

[0059] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A rapid detection system integrating sepsis pathogen and host, characterized in that, It includes a whole blood sampling and plasma separation unit, a nanobody magnetic bead immunoenrichment unit, a host and pathogen marker immunodetection unit, a pathogen enrichment lysis and isothermal nucleic acid amplification unit, a signal reading unit, and a combined risk assessment unit; The whole blood sample and plasma separation unit is used to receive whole blood samples and separate plasma and fluid fraction containing intact pathogens. Nanobody magnetic bead immunoenrichment unit for capturing and enriching pathogens in the fluid portion containing intact pathogens by superparamagnetic microbeads coupled with specific nanobodies. The host and pathogen biomarker immunoassay unit is used to detect host biomarkers and universal pathogen biomarkers in isolated plasma. The pathogen enrichment lysis and isothermal nucleic acid amplification unit is used to lyse and release nucleic acids from immuno-enriched pathogens and perform isothermal nucleic acid amplification. The signal reading unit is used to read the detection signals from the immunoassay unit and the nucleic acid amplification unit; The joint risk assessment unit is used to perform joint risk scoring based on the detection results obtained by the signal reading unit and output a report. The output risk score and report are auxiliary assessment information used by doctors to make a comprehensive judgment in conjunction with other clinical information.

2. The integrated rapid detection system for sepsis pathogen and host according to claim 1, characterized in that, In the whole blood sampling and plasma separation unit, after the whole blood sample enters the chip through the sample inlet, it first completes the rapid separation of plasma and blood cells through a hydrophilic porous membrane or equivalent microstructure; the separated plasma enters the immune detection area for detecting host markers and universal pathogen markers; the fluid portion containing intact pathogens enters the immune enrichment area for subsequent magnetic bead capture.

3. The integrated rapid detection system for sepsis pathogen and host according to claim 1, characterized in that, In the nanobody magnetic bead immunoenrichment unit, superparamagnetic microbeads coupled with specific nanobodies are used as capture carriers; for Escherichia coli, nanobody magnetic beads targeting the outer membrane protein OmpA are used for capture; for Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa, nanobody magnetic beads targeting high-abundance surface antigens of OmpK36, Protein A and OprF are used to expand the capture spectrum, respectively. After the magnetic beads are thoroughly mixed with the sample in the microfluidic channel, they are fixed in the enrichment area under the action of an external magnetic field. Unbound human cells, free DNA and inhibitors are discharged with the washing solution, thereby achieving pathogen concentration and background removal. Immunoenrichment efficiency and effective enrichment fold are characterized by the following formula: in, Indicates pathogen capture efficiency. This indicates the concentration of pathogens in the reaction solution after enrichment. This indicates the volume of the reaction liquid after enrichment. This indicates the concentration of pathogens in the original whole blood sample. This indicates the volume of the original whole blood sample. This indicates the effective enrichment factor of the pathogen.

4. The integrated rapid detection system for sepsis pathogen and host according to claim 1, characterized in that, The host and pathogen marker immune detection unit simultaneously detects four types of host markers and two types of universal pathogen markers in the plasma pathway. The four types of host markers include interleukin-6, procalcitonin, soluble CD14 subtype, and lactate. The two types of pathogen markers include lipopolysaccharide-binding protein-related signals and lipoteichoic acid-related signals. Interleukin-6 is used to reflect the early inflammatory initiation state, procalcitonin is used to help determine the bacterial infection tendency, soluble CD14 subtype is used to reflect the sepsis-associated monocyte-macrophage activation state, and lactate is used to indicate insufficient tissue perfusion and shock risk. The lipopolysaccharide-binding protein-related signal is used to indicate evidence of Gram-negative bacterial infection, and the lipoteichoic acid-related signal is used to indicate evidence of Gram-positive bacterial infection. The detection reagents for each biomarker are pre-embedded in the immunoassay area in lyophilized form; after the plasma flows through the corresponding reaction chamber, the biomarker forms a detectable complex with the fluorescently labeled antibody or equivalent signal probe, and the signal reading unit calculates the concentration of each biomarker based on the fluorescence intensity, internal reference signal and calibration curve.

5. The integrated rapid detection system for sepsis pathogen and host according to claim 1, characterized in that, In the enriched pathogen lysis and isothermal nucleic acid amplification unit, the immunoenriched magnetic bead-pathogen complex enters the lysis reaction zone and releases pathogen nucleic acid through chemical lysis, thermal lysis, or enzymatic lysis. The released nucleic acid enters the isothermal amplification zone for recombinase polymerase amplification or equivalent isothermal amplification reaction. The amplification primers are designed for the conserved sequence of the target pathogen and are consistent with the pathogen category corresponding to the immunoenrichment.

6. The integrated rapid detection system for sepsis pathogen and host according to claim 1, characterized in that, The combined risk assessment unit integrates pathogen evidence, host inflammatory response, and lactate perfusion risk; based on nucleic acid amplification results, universal pathogen marker results, and host marker concentrations, a pathogen-host combined risk score is constructed. in, This represents the combined risk score for sepsis, with a value ranging from 0 to 1. This represents the Sigmoid normalization function; Represents the model bias term; to These represent the weighting coefficients of each input indicator; This represents the evidence value for pathogen nucleic acid detection, with 1 for a positive result and 0 for a negative result, or it can be converted into a continuous evidence value based on the amplification time. The evidence value for universal pathogen markers is obtained by combining lipopolysaccharide-binding protein-related signals and lipoteichoic acid-related signals. This indicates the concentration of interleukin-6 detected. This indicates the reference threshold for interleukin-6; This indicates the detected concentration of procalcitonin. Indicates the reference threshold for procalcitonin; This indicates the detection concentration of soluble CD14 subtypes. Indicates the reference threshold for soluble CD14 subtypes; This indicates the concentration of lactic acid detected. Indicates the lactate reference threshold; the joint risk score As an intermediate quantitative indicator, this score is provided for clinicians to make a comprehensive judgment based on the patient's clinical manifestations. It does not constitute a direct diagnostic conclusion.

7. The integrated rapid detection system for sepsis pathogen and host according to claim 6, characterized in that, The joint risk assessment unit outputs results according to the following rules: When at least one of the pathogen nucleic acid test or universal pathogen marker is positive, and the host inflammatory marker reaches the set response level, the system outputs a high risk of infection or a high risk of sepsis; when the combined risk score is high and lactate exceeds the perfusion risk threshold, the system further outputs a high risk of septic shock; when the pathogen evidence is weak and the host response is normal or low, the system marks the result as suspected colonization, contamination, or requiring verification.

8. A method for rapid detection of sepsis pathogen and host, based on the system described in any one of claims 1-7, comprising the following steps: S1. Whole blood sample injection and plasma separation: The whole blood sample is injected into the whole blood sample injection and plasma separation unit to separate plasma and fluid fraction containing intact pathogens. S2, Immune detection: The plasma obtained in step S1 is introduced into the host and pathogen marker immune detection unit to detect host markers and universal pathogen markers; S3, Immunoenrichment: The fluid portion containing intact pathogens obtained in step S1 is introduced into the nanobody magnetic bead immunoenrichment unit, and the pathogens are captured and enriched by superparamagnetic microbeads coupled with specific nanobodies. S4, Lysis and Nucleic Acid Amplification: The immuno-enriched magnetic bead-pathogen complex is introduced into the enriched pathogen lysis and isothermal nucleic acid amplification unit to release pathogen nucleic acid and perform isothermal nucleic acid amplification. S5. Signal reading: Read the detection signals from steps S2 and S4 through the signal reading unit; S6. Combined Risk Interpretation: Input the read signals into the combined risk interpretation unit, calculate the risk score and output a report, which is used by clinicians to make a comprehensive judgment based on the patient's clinical signs and other laboratory test information.

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