Evaluation The Drug Resistance Of Escherichia Coli Isolated From A Zoo In Guangdong And Analysis Of Mcr-1 Epidemic Characteristics

In recent years,with the continuous application of antibiotics,drug resistance caused by the issue of widespread concern.The spread of drug resistance between humans and animals has been extensively studied.The zoos have a large number of animals.It is crowded with visitors,meanwhile it's a repository of drug-resistant bacteria.In order to provide data support for public health security,the study focus on one of the Zoo in Guangdong,China,to investigate the drug resistance distributed situation in the park.This investigation focused on the antibiotic resistance of E.coli isolated from the park including black swan area,kangaroo area,giant panda area and primate animal areas,in which are visitors are closely contact with the animals.66 E.coli isolates from 74 samples in different areas.This study reveals the spread of the situation.To provide a theoretical basis for the control of drug resistance.Besides the discovery of plasmid-mediated colistin-resistant strains,the cefotaxime resistant strains were also found.The minimum inhibitory concentration of different antimicrobial agents was determined by agar dilution method.The E.coli from the zoo have multiple drug resistance to cephalosporins,amphenicols and quinolones.The resistant rates of E.coli isolated from different regions were different for various antimicrobial agents.Take for cefquinoxime instance,the resistant rate of the strain isolated from the black swan region was 80%?28/35?,but the resistant rate of the strain isolated from the primate animal areas was only23.08%.It is noteworthy that the isolates of the highly isolated animal isolates have a higher rate of colistin resistance,reaching 61.2%?13/20?.PCR was used to detect the drug resistance genes.The positive rate of mcr-1 was 76.74%.E.coli were detected with mcr-1 were all in the monkey park.?specifically among two Macaca assamensis and their breeders?.Additionally,oqxAB,floR,and bla_CTX-M genes were also detected among the animals.Among them,80%?28/35?of the bacteria isolated from the Black Swan had bla_CTX-M genes and 47.06%?8/17?of the bacteria isolated from the kangaroo area carries bla_CTX-M.None of the above two regions detected mcr-1.Statistical analysis showed that there was no significant difference between resistant genotype and drug resistance phenotype.The PFGE showed close genetic relationship in those mcr-1 positive strain suggesting that there is a mutual transmission between strains.The mcr-1-positive plasmid transfer test was performed to obtain 5 conjugates.S1-PFGE and Southern blot indicated that it existed horizontal spread between humans and animals.The results of this study show that the drug resistance of E.coli in the zoo is very common,different areas of bacterial isolation rate differences exist.It may be related to medication habits.Different copies of the plasmid may mediate the transfer of mcr-1,however,some of the carrying mcr-1 strains may be propagated between breeders and animals.In addition to the above,should give the zoo captive animal bacterial resistance issues to attach great importance to the larger-scale investigation should continue to carry out.