The Studay Of Antimicrobial Resistance And Resistance Genes Among Escherichia Coli And Salmonella Isolated From Swine In Different Areas Of Shanghai

The pig farm E. coli and salmonella monitoring could not only control the distribution and trends of resistant strains and resistance genes, detected the evolution mechanism and mode of transmission of resistant bacteria and resistance gene, provided information to establish a unified, standardized testing standards of Shanghai,but also it could guide the rational use of antibiotics to the region’s farming owners, reduced the spread of antibiotic resistance to determine the measures the reliability and validity to curb the spread of bacterial resistance and helped the research institutions and pharmaceutical companies to develop new antibiotics.1The isolation and identification of Escherichia coli and SalmonellaThe identification of fecal samples collected from farms by selective culture medium selection, staining, TSI test and the automatic identification equipment. The results showed that:371E. coli and35Salmonella were solated from414samples, separation rates was89.6%,10.9%, respectively. The isolation rate of E. coli was significantly higher than Salmonella..2The research of drug resistance of E.coli strains and SalmonellaSusceptibility testing was performed for13antibiotics, the resistance rates of E.coli to ampicillin, spectinomycin, sulfamethoxazole, doxycycline, tetracycline, sulfonamides isoxazole were high, the lowest resistance rate was74.7%. Multi-drug resistance rate of E. coli was95.82%, mostly concentrated in the6-10antibiotic resistance; The most resistance drug to Salmonella strains was florfenicol, but polymyxin E was most sensitive, resistance rate was only11.4%.3Establishment of ESBLs genotypes Real-time Fluorescence Quantitative PCR detection methodAccording to the recommendation of the CLSI Initial screening and confirmatory methods (broth microdilution method) to screen ESBLs of E. coli isolated from pig farms, four genotypes of primers and probes were designed respectively, and established a method to rapid detection of ESBLs by quantitative PCR. Optimal concentration of primers and probes was0.5μmol/L,0.1μmol/L, respectively. Coefficient of variation of different concentrations were not more than1.5%in repeatability;The detectable threshold for quantitative PCR was101DNA copies/ul; The detectable threshold for the conventional PCR was104copies/ul. Correlation coefficient R2>0.99. This method was suitabled for rapid detection of ESBLs.4Study on molecular typing of Salmonella isolates from swineThe Salmonella DNA fingerprint database was determined through Ribo-Printer Microbial Characterization System, statistical the similarity relationship between the experimental strains.The electrophoresis patterns were analyzed by Bionumerisc soft ware. The four serotypes were identified by restriction enzyme PVUⅡ.6RP patterns were found among15strains of S.typhimurium.and7RP patterns were found among18strains of S. enteritidis. There was a RP type of S.choleraesuis and S. Agena.