Studies On Antibody Level Of Three Swine Virus Diseases Andthe Resistance Of Escherichia Coli. In Zhanjiang

Classical swine fever(CSF),porcine reproductive and respiratory syndrome(PRRS,also known as swine blue-ear),porcine pseudorabies(PR)are serious diseases in the pig industry.Escherichia coli.was one of the most common pathogens of humans and animals.Antimicrobial agents has been important measures to control infection.As misuse and abuse of antimicrobial agents,the resistance on Escherichia coli.of animal source was increasing,the treatment effect was declined by using antibacterial agents,and the resistant genes can horizontal transmission between people and animals,which damaged to the public health security seriously.In order to evaluate the immunity of pigs in Zhanjiang city,a total of 646 serum samples collected from 33 different scale pig farms in Zhanjiang from 2016 to 2018 were used to detect the antibody of CSF,PRRS and PR.The swine Escherichia coli.were isolated from Zhanjiang region by using the separation and identification of microorganism method.The minimum inhibitory concentrations(MICs)were determined from 12 kinds of antimicrobial agents to the Escherichia coli.isolated using broth micro-dilution method.The distribution of 10 resistant genes in swine Escherichia coli.were investigated by PCR.Results:(1)The average qualified rate of CSF antibody was 65.31%,PRRS was 67.65%,and PR was 86.5%.The percentage of PR antibody in pig farms with different stocks was higher,and the other two antibody test results showed that the smaller the size of the pig farm,the lower the antibody pass rate.(2)The resistance of 42 swine Escherichia coli.against antimicrobials showed different levels.The resistance rate of penicillin and erythromycin were 100%,followed by tetracycline,chloramphenicol and norfloxacin,which were as high as 97.6%.The resistant rate of cefotaxime,neomycin and doxycycline were 80.9%,57.2% and 28.7% respectively.42 strains were sensitive to amikacin.The MICs value of lincomycin and rifampicin on isolated strains were larger(64-256 ?g/m L,16-256 ?g/m L).(3)The detection rates of resistant genes: The detection rates of TEM,CTX-M and OXA were 54.76%,26.19% and 23.81% in ?-lactams respectively.The detection rates of tet A,tet B and tet C were 100%,7.14% and 11.96% in tetracyclines respectively.The detection rates of Cat1 and Cml A were 59.52% and 61.9% in amphenicols.The detection rates of sul2 and sul3 were 71.43% and 45.24% in sulfonamides.Conclusions:(1)The average qualified rate of PR antibody was higher,CSF and PRRS were lower in zhanjiang area,which should be strengthened the monitoring and immunity.(2)The isolated swine Escherichia coli.had serious resistance to the common antimicrobials in zhanjiang area,the detection rates of resistant genes were higher,and the multi-drug resistance phenomenon was widespread.