| Antimicrobial agents has been widely used in veterinary,as commonly used drugs for the treatment and prevention of bacterial diseases or used extensively as feed additive in animal husbandry.The incidence of resistance and multidrug-resistance among pathogenic bacterium has been increasing,which has become a great threat to animal husbandry and human health.Researches on antimicrobial resistance characteristics and epidemiological study of resistance genes of E.coli from animals,which is helpful to learn enxrgence and dissemination of resistant genes,and guide the rational use of antimicrobial agents in veterinary medicine.A total of 136 samples were collected from rabbits in different farms of Sichu an province during 2014 to 2015 year,and Detered 97 were E.coli form 136 bacteri-al strains by the test of morphology,biochemical characteristics and PCR technique.This study used K-B method for 24 antimicrobial agents sensitivity test of E.coli acc-ording to CLSI guidelines.The results showed that the resistant rates of AMO,LEX,AMK,GEN,Kana,STR,DOX,TET and SXT more than50%,especially for AMO,DOX and TET,such as 3 drugs showed high levels of resistance(?85.56%).The level of resistance to FOX,CZO,CRO,CAZ,CTX and PB resistance rate between 9.28%?29.89%.All isolates had multiple resistance,most isolates exhibited multidrug res-istance to 6?17 antimicrobial agents(88.66%).The phenotype of ESBLs was identified and determined by CLSI standard method,the results showed that there were 71.13%(69/97)of E.coli strains produced ESBLs.ESBLs producing strains were resistant to more serious than non-ESBLs-producing ones,and there was a sign-ificant difference between themto FOX,CZO,CAZ,AMI,Kana,STR,NOR,NER(P<0.05),a extremely significant difference between them to NEO,NEX,LVF(P<0.01).The multi-drug resistance rate of ESBLs producing were resistant to serious than no n-producing ones.Detection of drug resistance genes by PCR method(ESBLs genes:TEM,CTX-M,OXA,SHV;PMQR genes:qnrA,qnrB,qnrC,qnrD,qnrS,qnrVC,qepA,oqxA,oqpxB,aac(6')-Ib-cr;16SrRNA methylation genes:armA,rmtA,rmt B,rmtC,rmtD,rmtE,npmA;tet genes:tetA,tetB,tetC,tetD,tetE,tetM,tetO,tetL,tetK;Florfenicol resistance genes:floR,cfr).The results showed that the detection rate of ESBLs gene TEM,CTX-M,OXA genotype was 44.33%(43/97),45.36%(44/97),16.49%(16/97),the enzyme producing strains belong to 10 gene subtypes,the dominant ones of which were TEM-1,CTX-M-14 and OXA-1.The detection rate of PMQR gene qnrD?qnrS?aac(6')-Ib-cr?oqxA?oqxB genotype was 59.79%(58/97),59.79%(58/97),80.41%(78/97),63.91%(62/97),51.54%(50/97),the enzyme producing strains belong to 3qnr gene subtypes,the dominant ones of which were qnrDl,qnrS 1.The detection rate of 16SrRNA methylation gene armA,rmtB genotype was 4.12%(4/97),3.09%(3/97).The detec-tion rate of tet gene tetA,tetB,tetC genotype was 61.86%(60/97),84.54%(82/97),16.49%(16/97),tetB is the highest detectable gene among all of the tested genes in this study.The detection rate of floR was 8.25%(8/97).The number of resistant genes of ESBLs strains was significantly higher than that of non ESBLs strains.and the rate of drug resistance and multiple drug resistance rates were higher than those with less resistant genes.The drug resistance rate and multi drug resistance rate of the strains with more resistant genes were significantly higher than those with less resistance genes. |
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