Study And Effect Evaluation Of MLVA Typing Of Staphylococcus Lauren Based On Capillary Electroplate

With the continuous diversification of the development of dairy industry in China,the incidence of mastitis in dairy cows remains high,and there are many kinds of clinical symptoms.Due to its complicated etiology and obvious clinical symptoms,the number of cases of recessive mastitis has increased year by year,and it has gradually become a disease that is difficult to treat.Staphylococcus Lauren is one of the pathogenic microorganisms of cow mastitis,which is easy to develop antibiotic resistance,and the clinical treatment effect is not obvious.The isolation and identification of bacteria is the most widely used method for determining pathogenic microorganisms.Molecular typing methods have been widely used in the epidemiology of pathogenic bacteria in recent years.The molecular typing of Staphylococcus Lauren in different regions is different.Therefore,molecular migration methods can be used to further explore the evolutionary mode and transmission route of the strains of staphylococcus Lauren.In this study,Staphylococcus Lauren was isolated from the milk samples of cow mastitis in some areas of Jilin Province,and a molecular gel typing method based on capillary electroplate was established.300 samples of dairy cows with mastitis and no drug treatment were collected from 15 dairy farms in Jilin Province,156 Gram-positive bacteria isolated by separation and purification,Gram stain microscopy and OptiRead automatic microbial identification system,among them,18 strains of Staphylococcus Lauren,and 11 strains were successfully classified.At the same time,13 antibiotics were selected for all Staphylococcus Lauren for drug susceptibility analysis,among the 11 strains successfully typed,2 strains were fully resistant.The resistance rate of 11 strains to antitoxin,enticing,penicillin,cinnamon,clinician and phenomenological was 100%,the remaining antibiotic resistance rates were erythrocyte(72.7%),tetracycline(63.6%),nonreciprocal(63.6%),methicillin(45.4%),ampicillin(36.3%),and Aureomycin(18.1%),lidocaine(18.1%).and Aureomycin(18.1%),lidocaine(18.1%).Aureomycin and lidocaine are antibiotics that are sensitive to staphylococcus Lauren and have also developed resistance.MLVA typing was performed by metamorphism analysis of 8 different VNTR loci.First,optimize the PCR reaction conditions,and then optimize the annealing conditions of the agaric gel electroplate for 8 reaction conditions,phenotype of the best PCR reaction product for each VNTR site by capillary electroplate.Reference to the MLVA typing database of staphylococcus Lauren,the number of repeating units of the same strain at 8 VNTR sites is encoded was sequentially encoded to form an MLVA profile for typing.Results 11 strains of Staphylococcus Lauren were successfully divided into four types,named JLSaul,JLSau2,JLSau3,JLSau4.Through gene sequencing comparison,JLSaul type is consistent with MT3027 type in the database,and other three have similar types.Cluster analysis of the four types and the strain types in the database showed that the four genotype were similar,JLSaul and JLSau4 were the most similar,and between JLSau2,JLSau3 and JLSau4 were higher similarity.