67 results about "Parahaemolyticus vibrio" patented technology

The invention discloses a lytic bacteriophage vBVpaSR40Z and application of the lytic bacteriophage vBVpaSR40Z to prevention and control of vibrio parahaemolyticus in an aquaculture environment. The preservation number of the vibrio parahaemolyticus phage vBVpaSR40Z is as follows: GDMCC No: 67440-B1, and the vibrio parahaemolyticus phage vBVpaSR40Z is The R40Z can be used for cracking multiple strains of vibrio parahaemolyticus and vibrio alginolyticus, has the capability of adapting to an aquaculture environment, and keeps relatively high activity within the range of 4-25 DEG C and pH of 4-10; no virulence gene or drug-resistant gene is detected through genome analysis, and phylogenetic and whole genome comparison shows that the similarity between R40Z and a related phage is lower than a species level threshold value, so that R40Z is a new phage species; the R40Z can obviously inhibit the growth of a host under various infection complex numbers. The R40Z has the advantages of strong splitting capacity, good environmental stability, high genome safety, unique evolutionary characteristics and the like, and is an aquatic vibriosis biological prevention and control bacteriophage with application potential.

The invention discloses vibrio parahaemolyticus deoxyribozyme screening and label-free biosensor development. The vibrio parahaemolyticus deoxyribozyme screening and label-free biosensor development comprises the following steps: (1) obtaining a vibrio parahaemolyticus deoxyribozyme sequence; (2) optimizing reaction conditions of the vibrio parahaemolyticus label-free biosensor; and (3) detecting the vibrio parahaemolyticus. The detection principle of the sensor is as follows: when vibrio parahaemolyticus exists, deoxyribozyme is triggered to be self-cleaved, a generated cleaved short chain can be used as a primer for starting rolling circle amplification (RCA), a large number of long-chain DNA products with repeated series G-quadruplex sequences are generated by amplifying a designed RCA annular template, G-quadruplex and ThT can form a G-quadruplex / ThT compound, and the long-chain DNA products can be used for detecting the vibrio parahaemolyticus. The fluorescence is generated under the excitation wavelength of 439 nm, and the higher the concentration of the vibrio parahaemolyticus is, the higher the fluorescence intensity of the system is, so that the simple, convenient, rapid, low-cost and high-sensitivity detection of the vibrio parahaemolyticus is realized.

The invention belongs to the technical field of microbial antibacterial preparations, and particularly discloses a novel strong vibrio parahaemolyticus bacteriophage isolated strain vBVpSCC6 and application of the novel strong vibrio parahaemolyticus bacteriophage isolated strain vBVpSCC6. The bacteriophage vBVpSCC6 is preserved in the Guangdong Microbial Culture Collection Center on September 14, 2020, and the preservation number is GDMCC (China General Microbiological Culture Collection Center) NO: 61189-B1. The bacteriophage has good tolerance to environments such as temperature, pH, ultraviolet rays and the like, and has a good prevention and control effect on aquatic product pollution caused by vibrio parahaemolyticus. The bacteriophage has a lysis effect on multi-drug-resistant vibrio parahaemolyticus, can replace antibiotics to play a bacteriostatic role, effectively solves the problem of drug resistance faced by current antibiotic treatment, and has relatively good utilization value and application prospect. The bacteriophage can also be prepared into a composition with other bacteriophages to play a synergistic effect, and the bacteriophage can be applied to wider-spectrum antibacterial or bacteriostatic application.

The invention belongs to the field of microbial culture, and particularly relates to an enrichment medium for reducing expression of surface polysaccharide of vibrio parahaemolyticus. According to the formula of the polysaccharide low-expression enrichment culture medium, nutritional ingredients in a specific proportion and specific polysaccharide expression inhibition conditions are selected, so that the expression quantity of surface lipopolysaccharide and capsular polysaccharide after enrichment of vibrio parahaemolyticus is lower than the expression quantity of polysaccharide after enrichment of normally cultured vibrio parahaemolyticus; expression of lipopolysaccharide and capsular polysaccharide on the surface layer can be inhibited to a certain extent, so that outer membrane protein can be better exposed on the surface of a thallus, and immunodetection of vibrio parahaemolyticus is facilitated. The invention provides a technical basis for developing a complete vibrio parahaemolyticus immunodetection method.

The invention relates to an on-site synchronous quantitative determination method for three pathogenic bacteria in marine sediments, and belongs to the technical field of pathogenic bacteria detection.The three pathogenic bacteria are vibrio parahaemolyticus, vibrio alginolyticus and escherichia coli O157, and the method comprises the steps that marine sediment samples are collected and put into a centrifugal tube filled with sterile seawater, and are evenly mixed and centrifuged; taking the supernate as a template for LAMP amplification, respectively adding the supernate into detection tubes of an LAMP reaction system preloaded with the three pathogenic bacteria, and sealing. Placing the detection tube into a detection channel of a portable electronic isothermal gene amplification instrument, and determining a delta C4-t curve, a dv / dt-t curve and Tp; and after the determination is finished, substituting the Tp value into a working curve formula to calculate the content / concentration of the three pathogenic bacteria of the corresponding marine sediment sample in the detection tube. According to the method disclosed by the invention, Bst DNA polymerase and betaine are not needed in the reaction, so that the cost of LAMP analysis is reduced by at least 50%, the operation is simple and convenient, and simultaneous quantitative determination of the three pathogenic bacteria can be completed on site within 1h.

The invention discloses ultrasensitive detection of vibrio parahaemolyticus by a CRISPR (clustered regularly interspaced short palindromic repeats) electrochemical biosensor based on PCR (polymerase chain reaction) and a hairpin DNA (deoxyribonucleic acid) probe, which comprises the following steps: preparing a gold nanoelectrode, modifying the gold nanoelectrode by using the hairpin DNA probe, performing polymerase chain reaction amplification to obtain a PCR amplification product, adding the PCR amplification product into a CRISPR system, uniformly oscillating, and detecting the vibrio parahaemolyticus by using the CRISPR electrochemical biosensor. Placing in a 37 DEG C constant-temperature metal bath for pre-reaction for 10 minutes, and dropwise adding the obtained reaction system to the surface of the hairpin DNA probe modified gold nanoelectrode. The method disclosed by the invention is high in overall repeatability and stability, the modification density of the surface of the electrode can be reduced, the steric hindrance effect is further reduced, the trans-cutting efficiency is improved, and in actual detection, the method shows remarkable sensitivity, is high in specificity, short in time consumption, low in cost and simple and convenient to operate, and can be applied to field detection.

The invention discloses a preparation method of a boiling antigen for vibrio parahaemolyticus serum agglutination. The preparation method comprises the following steps: selecting common serotype vibrio parahaemolyticus in monitoring for resuscitation; scraping a ring of placenta by using 10 mu L of an inoculating loop, dissolving the placenta in 1 mL of normal saline to prepare a bacterial suspension, and preparing 3 tubes of bacterial suspensions from each strain; boiling the bacterial suspension in boiling water for 1 hour, 45 minutes and 30 minutes respectively; and after boiling, centrifuging at 10000 rpm for 10 minutes, discarding the supernate, and reserving the precipitate as a boiling antigen for serum agglutination. The result shows that the agglutination accuracy after boiling for 1 hour is 100%, and the agglutination degree is 2 + or above; and no significant difference exists between 45 minutes of boiling and 1 hour of boiling, and no significant difference exists between 30 minutes of boiling. Compared with a high-pressure method, the method has the advantages that the operation time is shortened by 2-3 hours, special equipment certificates are not needed, and the method is suitable for daily detection and food poisoning traceability.

The application provides a bacillus desiccabilis strain XT23 microbial agent, a preparation method and application thereof, and belongs to the technical field of biological agents. A biological agent comprises a bacillus desiccabilis strain XT23, a fermentation treatment liquid of the bacillus desiccabilis strain XT23, or supernatant separated from the fermentation treatment liquid of the bacillus desiccabilis strain XT23. The fermentation treatment liquid is obtained by acid treatment and heat treatment of the fermentation liquid of the bacillus desiccabilis strain XT23, which effectively promotes spore formation, inactivates miscellaneous bacteria, significantly improves the stability and storage period of effective live bacteria, maximally retains antibacterial active substances in the fermentation liquid, and makes the inhibition effect of the final biological agent on Vibrio parahaemolyticus equivalent to that of fresh fermentation liquid. Meanwhile, the addition of the auxiliary material has a protective and slow-release effect on the active ingredients, and further enhances the convenience and effect persistence of application.

The present application belongs to the field of microbial culture, and particularly relates to a culture medium for reducing expression of surface polysaccharide of Vibrio parahaemolyticus. The formula of the polysaccharide low-expression culture medium is selected from specific proportion of nutritional components and specific conditions for inhibiting polysaccharide expression, so that the expression amount of surface lipopolysaccharide and capsule polysaccharide of Vibrio parahaemolyticus after the culture medium is increased is lower than the expression amount of polysaccharide of Vibrio parahaemolyticus after normal culture, the expression of surface lipopolysaccharide and capsule polysaccharide can be inhibited to a certain extent, the surface of the bacterial body can better expose outer membrane protein, and the immunodetection of Vibrio parahaemolyticus is facilitated. The present application provides a technical basis for developing a complete immunodetection method of Vibrio parahaemolyticus.

The present invention discloses a detection primer, a kit and its application for Vibrio parahaemolyticus, comprising an upstream primer F and a downstream primer R; the upstream primer R is selected from one or more of SEQ ID NO.10, SEQ ID NO.26 and SEQ ID NO.40, and the downstream primer R is selected from one or more of SEQ ID NO.11, SEQ ID NO.27 and SEQ ID NO.41. The primer set can be used in the detection of Vibrio parahaemolyticus and the preparation of Vibrio parahaemolyticus detection preparations and kits for non-diagnostic purposes. The present application establishes a standardized VpTPD pathogen detection method and develops a rapid, convenient, highly sensitive, highly specific, economical and practical detection primer and kit that can be widely promoted for pathogen detection, thereby solving the effective prevention and efficient monitoring of Vibrio parahaemolyticus.

The application discloses a lytic bacteriophage vB_VpaS_R40Z and application thereof in preventing and controlling Vibrio parahaemolyticus in aquaculture environment. The Vibrio parahaemolyticus bacteriophage vB_VpaS_R40Z has a preservation number of GDMCC No: 67440-B1. The R40Z can lyse multiple strains of Vibrio parahaemolyticus and Vibrio alginolyticus, and has the ability to adapt to the aquaculture environment, and remains high activity within the range of 4-25 DEG C and pH 4-10; genome analysis does not detect virulence genes or drug resistance genes; phylogenetic comparison with the whole genome shows that the similarity of R40Z with the related bacteriophage is lower than the species level threshold, and R40Z is a new bacteriophage species; R40Z can significantly inhibit the growth of the host under multiple infection multiplicities. R40Z has the advantages of strong lytic ability, good environmental stability, high genome safety and unique evolutionary characteristics, and is a water product vibrio disease biological prevention and control bacteriophage with application potential.

The application discloses a colorimetric-SERS dual-mode detection and photothermal sterilization method for specifically detecting Vibrio parahaemolyticus and application thereof, and belongs to the technical field of food safety biology. The application takes Vibrio parahaemolyticus as a target, and prepares a multifunctional magnetic composite nanomaterial through layer-by-layer assembly. Firstly, the superparamagnetic separation performance of the magnetic composite nanomaterial is combined with magnetic chromatography to achieve the effect of rapidly separating bacteria from a complex food matrix. Secondly, the colorimetric and SERS sensing signals of the magnetic composite nanomaterial are used to quantitatively detect bacteria in a short time, high precision and high stability in a dual-mode. Finally, the photothermal performance of the magnetic composite nanomaterial is used to kill the detected bacteria by photothermal sterilization, so that the hazard control at the back end of detection is completed.

The invention discloses a portable electrochemical biosensor for detecting vibrio parahaemolyticus, the principle of the invention can be also suitable for detection of other pathogenic microorganisms, and the portable electrochemical biosensor comprises a PVC substrate, a sample pad, a capture pad, a screen printing electrode and a water absorption pad. According to the invention, the advantage of high sensitivity of electrochemistry and the advantage of no separation of the test strip are combined together, the vibrio parahaemolyticus is captured by using the aptamer and is fixed on the detection line, the signal probe is dropwise added, the electrochemical workstation is used for detection, and quantitative detection of the vibrio parahaemolyticus is realized by adopting a signal subtraction output mode. The method has the advantages of low cost, high detection speed, high sensitivity, simplicity in operation and the like. The requirements of customers for on-site rapid detection can be met, and food poisoning of patients can be effectively prevented.

The invention discloses a broad-spectrum antibacterial lactobacillus plantarum, and belongs to the technical field of microorganisms. The lactobacillus plantarum 9-6 is separated from animal feed, the preservation number is CGMCC (China General Microbiological Culture Collection Center) No.32568, the lactobacillus plantarum 9-6 and fermentation liquor thereof have an obvious inhibition effect on common vibrio parahaemolyticus, vibrio alginolyticus, vibrio harveyi and vibrio vulnificus, and the lactobacillus plantarum 9-6 and the fermentation liquor thereof have the advantages that the lactobacillus plantarum 9-6 and the fermentation liquor thereof have the obvious inhibition effect; and in addition, the antibacterial agent has a relatively good antibacterial effect on common staphylococcus aureus, escherichia coli, listeria monocytogenes, salmonella enterica and bacillus cereus. The lactobacillus plantarum 9-6 has probiotic safety, can grow under an initial pH condition of 4-10 and a high-salt environment, and plays a role in bacteriostasis under an acidic condition. The invention lays a foundation for developing a good antibacterial probiotic preparation and application of a fermentation culture thereof.

The invention relates to a primer probe group, a multiplex fluorescent quantitative PCR method and a kit for simultaneously detecting six pathogenic bacteria, and belongs to the technical field of molecular biology, the primer probe group comprises primer sequences and probe sequences shown in SEQ ID No.1-18 in a table 1; the 5'end of each probe sequence is modified with a reporter group, and the 3 'end of each probe sequence is modified with a quenching group; the reporter group is Cy5, FAM and VIC, and the quenching group is Eclipse. The invention provides a method for simultaneously detecting six pathogenic bacteria including vibrio parahaemolyticus, salmonella, staphylococcus aureus, escherichia coli O157: H7, listeria monocytogenes and shigella in the same reaction system by combining a multiple real-time fluorescent quantitative PCR (Polymerase Chain Reaction) technology. The multiplex real-time fluorescent quantitative PCR kit provided by the invention is used for detecting the six pathogenic bacteria, can improve the detection sensitivity and specificity, greatly improves the detection efficiency, and overcomes the defects of complex steps, long detection period and incapability of adapting to large-scale rapid detection in the conventional detection method.

The invention provides application of an antibacterial peptide targeting a vibrio parahaemolyticus outer membrane protein LptD, and belongs to the technical field of antibacterial peptides. The amino acid sequence of the antibacterial peptide targeting the vibrio parahaemolyticus outer membrane protein LptD provided by the invention is as shown in SEQ ID NO. 1. The antibacterial peptide provided by the invention can specifically inhibit vibrio parahaemolyticus, and the integrity of an outer membrane is destroyed by combining a beta-taco structural domain of LptD protein, so that cellular contents are leaked. In a ready-to-eat salmon model, the load of artificially inoculated vibrio parahaemolyticus can be reduced by 1.51 log CFU / mL by soaking 64 micrograms / mL of the antibacterial peptide disclosed by the invention for 4 hours, and meanwhile, the regeneration of a biofilm in a storage period is remarkably inhibited. Safety experiments prove that the antibacterial peptide provided by the invention has the advantage of high safety.

The invention discloses a vibrio parahaemolyticus phage Ph19S9E2 and application thereof, the vibrio parahaemolyticus phage Ph19S9E2 is preserved in the China Center for Type Culture Collection (CCTCC) located in Wuhan University in China on April 15, 2025, and the preservation number is CCTCC NO: M2025789. The vibrio parahaemolyticus phage Ph19S9E2 has the advantages that the vibrio parahaemolyticus phage Ph19S9E2 can be used for preparing the vibrio parahaemolyticus phage Ph19S9E2; the vibrio parahaemolyticus bacteriophage provided by the invention can specifically and effectively split vibrio parahaemolyticus VP19S9E2, and has high-strength host specificity.

The invention relates to the technical field of space-time sequences, in particular to a method for predicting the detection rate of vibrio parahaemolyticus based on ST-Transform, and the method comprises the following steps: S1, carrying out data preprocessing, the data preprocessing comprises the following small steps: (1) data collection: collecting multi-source data related to vibrio parahaemolyticus, wherein the multi-source data comprises a historical detection rate, environmental factors (such as temperature and humidity), economic data (such as regional GDP and population density) and the like; according to the method for predicting the detection rate of the vibrio parahaemolyticus based on the ST-Transform, independent operation of a space attention module and a time attention module can be achieved, information transmission deviation is avoided, the calculation efficiency is improved, the expression ability and robustness of the model can be improved, the model can be helped to better mine driving factors behind data, and the detection rate of the vibrio parahaemolyticus is improved. And the method can also be used for capturing a complex time-space relationship and adaptively embedding a dynamic relationship capable of learning time sequence information.

The application discloses application of quinoline in prevention and treatment of Vibrio parahaemolyticus. The application studies bacteriostatic activity of quinoline on Vibrio parahaemolyticus, and further explores influence of the quinoline on growth inhibition rate of Vibrio parahaemolyticus, biofilm formation, and influence of the quinoline on prevention and treatment effects of Vibrio parahaemolyticus on Neocaridina denticulata. The result proves that the quinoline can effectively prevent and treat Vibrio parahaemolyticus disease of the Neocaridina denticulata.

This invention discloses a quadruple Taqman qPCR reagent for detecting foodborne pathogens in aquatic products. The foodborne pathogens are Vibrio parahaemolyticus, Vibrio vulnificus, Shigella, and Staphylococcus aureus. The reagent includes specific primers and Taqman probes corresponding to the four foodborne pathogens. This invention provides a quadruple Taqman qPCR reagent with high efficiency, accuracy, sensitivity, and speed, offering an accurate, rapid, efficient, and economical method for detecting the above four foodborne pathogens in the quality and safety testing of aquatic products and their processed products. This is of great significance for ensuring the safety of aquatic products for consumption in my country.

Primers and primer sets for amplification of Vibrio parahaemolyticus DNA and methods of detecting Vibrio parahaemolyticus using the primers and primer sets.

The invention discloses a double microdroplet digital PCR (polymerase chain reaction) detection primer group for enterocytozoon hepatopenaei and vibrio parahaemolyticus and a kit of the double microdroplet digital PCR detection primer group. The sequence of the EHP primer probe set is as shown in SEQ ID NO.1-3, and the sequence of the VPAHPND primer probe set is as shown in SEQ ID NO.6-6. The method has the advantages that absolute quantitative analysis of pathogens can be realized, the sensitivity and repeatability are better, the operation steps are simplified, the result interpretation is more visual and reliable, the two pathogens of EHP and VPAHPND can be simultaneously detected by adopting a two-color fluorescent probe method, and the prawn disease detection efficiency is improved.

The invention discloses a crRNA sequence and a plasmid for targeting vibrio parahaemolyticus based on CRISPR-Cas13a (clustered regularly interspaced short palindromic repeats) and application of the crRNA sequence and the plasmid. According to the invention, crRNA of a targeted T2RHS-Nuc gene is designed, a plasmid of tetracycline-induced expression Cas13a protein is established, the plasmid is introduced into vibrio parahaemolyticus under the assistance of escherichia coli and targets a target gene, and after mRNA of the target gene is recognized, targeted cleavage activity is generated, so that the affiliated cleavage activity of Cas13a is activated, a transcript of a bacterial strain is randomly cleaved in the bacterial body, and the expression of the Cas13a protein is promoted. When the transcript is necessary for the growth of the vibrio parahaemolyticus, the specific death of the vibrio parahaemolyticus can be caused. The crRNA and Cas13a protein expression vector and the sterilization method thereof provided by the invention do not induce vibrio parahaemolyticus to generate drug resistance, are a good alternative method for vibrio parahaemolyticus disease source control by using a traditional bactericide, and have a very good application prospect.

The invention provides a multicolor colorimetric detection method of vibrio parahaemolyticus and application of the multicolor colorimetric detection method. The multi-colorimetric detection method comprises the following steps: carrying out catalytic oxidation on TMB (Tetramethylbenzidine) by adopting G-quadruplex DNAzyme to obtain TMB < 2 + >, etching a gold nanorod by the TMB < 2 + > to obtain TMB < 2 + >-AuNRs, and carrying out multi-colorimetric immunodetection on the vibrio parahaemolyticus; the G-quadruplex DNAzyme has peroxidase-like activity, and is obtained by combining a G-quadruplex mediated by a recombinase polymerase with hemin, and the G-quadruplex is used as a carrier of the recombinant polymerase. By adopting the technical scheme provided by the invention to detect the vibrio parahaemolyticus, the method has the advantages of high sensitivity, strong specificity and simplicity and convenience in operation, can realize visual detection, and is convenient and quick; particularly, the method can be applied to food safety detection, so that not only can the detection accuracy be improved, but also the detection time can be greatly shortened.

The present application relates to the technical field of molecular diagnosis, and discloses specific primers and a fluorescent PCR detection method for identifying Vibrio parahaemolyticus KUT2 type strains, and provides primers KUT2-F / R and a TaqMan probe for identifying Vibrio parahaemolyticus KUT2 type strains, and establishes a fluorescent PCR method (TaqMan probe method). The present application can quickly identify the main Vibrio parahaemolyticus KUT type prevailing in diarrhea patients in China, expand the Vibrio parahaemolyticus serotyping system, and provide a more accurate tool for epidemiological investigation and tracing. The present application has reached the level of the fluorescent PCR technology in terms of amplification efficiency, sensitivity and specificity, thereby realizing efficient and specific detection of KUT strains, and can judge whether the strain is the main KUT type prevailing in China within 1 hour, and fully meets the actual use detection requirements.

The invention discloses a vibrio parahaemolyticus hfq gene deleted strain as well as a construction method and application thereof. The invention provides a deletion strain, a construction method of the deletion strain and application of the deletion strain in construction of an enrofloxacin drug resistance model. The invention finds that after the hfq gene is deleted, the drug resistance to the enrofloxacin is obviously increased. It is further proved that the vibrio parahaemolyticus ATCC33846 delta hfq deletion strain enhances the drug resistance to enrofloxacin by improving the excretion of rhodamine 6G. The vibrio parahaemolyticus deletion strain is constructed by utilizing high efficiency and accuracy of homologous recombination, and the important effect of the hfq gene on the drug resistance of the vibrio parahaemolyticus is proved by comparing the drug resistance of the deletion strain and a wild strain on enrofloxacin. The compound can be used for developing a new therapy for drug-resistant bacteria or improving an existing antibacterial strategy.

The invention belongs to the technical field of biological detection, and discloses a multiple qPCR (quantitative polymerase chain reaction) kit for detecting food-borne pathogenic bacteria of aquatic products and application of the multiple qPCR kit. The kit comprises primers and a probe group for detecting vibrio parahaemolyticus, listeria monocytogenes and salmonella, and the sequences of the primers and the probe group are as shown in SEQ ID NO.1-9. According to the invention, probes with different fluorescence labels are utilized to realize simultaneous detection of three food-borne pathogenic bacteria of vibrio parahaemolyticus, listeria monocytogenes and salmonella in aquatic products. The method has the characteristics of short time consumption, good specificity, high sensitivity, high economic benefit and the like, has important significance on molecular diagnosis of the food-borne pathogenic bacteria in the aquatic products, and meets the detection requirements of simultaneously detecting the three food-borne pathogenic bacteria in the aquatic products.

The present invention discloses a large yellow croaker collagen antibacterial peptide LP-P1, whose amino acid sequence is KRVRAGMMMRKVAV and molecular weight is 1633 daltons. Experiments have proved that the antibacterial peptide LP-P1 of the present invention can effectively inhibit the growth of Vibrio parahaemolyticus and Vibrio alginolyticus, and is not prone to drug resistance, and can be used as a good substitute for antibiotics for the prevention and treatment of Vibrio parahaemolyticus and Vibrio alginolyticus. The present invention lays a foundation for further research on using large yellow croaker collagen antibacterial peptides as feed additives and biomedical development in the future.

The present application relates to oligosaccharide composition and its use. The present application particularly relates to the use of oligosaccharide composition in the preparation of products for preventing and / or treating aquaculture diseases caused by Vibrio parahaemolyticus, Vibrio harveyi and Streptococcus agalactiae, wherein the oligosaccharide composition is obtained by degrading polygalacturonan or pectin by a polygalacturonase as shown in SEQ ID No: 1, under the conditions of a polygalacturonase concentration of 0.045 mg / mL to 0.055 mg / mL, a polygalacturonan concentration of 7% to 9%, and a degradation time of 12 hours to 20 hours. The present application also relates to the use of oligosaccharide composition in aquaculture. The oligosaccharide composition of the present application has good bacteriostatic effect and disease prevention and control effect in aquaculture.

The invention discloses construction and application of a vibrio parahaemolyticus capsular polysaccharide synthesis gene cluster and lipopolysaccharide synthesis HldE mutant strain, and belongs to the technical field of molecular biology and genetic engineering.According to the construction method, an overlapping extension PCR technology is adopted for constructing a kanamycin resistance gene knockout fusion fragment, the fusion fragment is cloned into a suicide plasmid pDS132, and the suicide plasmid pDS132 is used for preparing the HldE mutant strain of the vibrio parahaemolyticus capsular polysaccharide synthesis gene cluster and lipopolysaccharide synthesis HldE mutant strain. A recombinant suicide plasmid is introduced into vibrio parahaemolyticus through conjugational transfer, and sucrose-induced double-exchange homologous recombination and kanamycin resistance screening are utilized to efficiently obtain a capsular polysaccharide synthetic gene cluster and an HldE gene knockout mutant strain. The invention further discloses an application of the mutant strain in evaluating the exposure of the outer membrane protein, and discloses the influence of a capsule and a lipopolysaccharide layer on the accessibility of an outer membrane protein antibody. The method is easy and convenient to operate and high in screening efficiency, and an effective tool is provided for vibrio outer membrane protein function research, vaccine target screening and pathogenic mechanism analysis.