Characterization,Antimicrobial Resistance And Genetic Analysis Of Important Intestinal Bacteria Recovered From The Companion Animals In Hangzhou

Nowadays,companion animals are playing an increasingly important role in people's daily life.Previous studies showed that the intestinal flora of human and pets would subtly change because of the intimate and close contact between human and companion animals.This will inevitiablely increase the possibility of the spreading and dissemination of multiple-durg-resistant bacteria.Therefore,companion animals could serve as an important reservoir for zoonotic transmission and antimicrobial resistant bacterial infections,which is one of the most important public health problems.To fill the major knowledge gap for zoonotic and antimicrobial-resistant bacteria in compainion animals,this study carried out an investigation of compainion animals from veterinary teaching hospital affiliated to Zhejiang University in Hangzhou.The main contents of the research include:(1)Isolation and identification of intestinal isolates from compainion animals,including canine and feline;(2)Study of antimicrobial resistance and MLST typing of E.coli recovered fecal samples in compainion animal;(3)Invextigation on antimicrobial resistance and genomic characterization of Salmonella isolates from fecal samples in the compainion animals.1.Isolation and identification of intestinal bacterial isolates from canine and feline:The research collected 137 samples from March to December 2018.In these samples,54 samples were from cats and 83 samples were from dogs.Totally,1003 isolates were isolated.The popular strains were E.coli(27.5%),Enterococcus faecalis(17.1%)and Proteus mirabilis(13.9%).Moreover,under different conditions,including pet species,health conditions and ages,the composition ratio of isolates was similar,which demonstrated that dominant bacteria in initial flora were relatively stable.2.Antimicrobial resistance and MLST typing of E.coli from canine and feline intestines:This study recovered 276 E.coli isolates.Research showed that these E.coli isolates were highly resistant to NAL(60.5%),SXT(76.1%),and AMC(62.3%).Strains were more sensitive to new drugs such as CST(6.9%)and TEM(12.3%).There was a certain correlation between bacterial resistance and pet health status or antibiotic use history.Strains from sick pets showed higher resistance to drugs than that in healthy pets.In addition,antibiotic treatment will increase bacterial resistance.The MLST typing results of E.coli showed that the isolates featured with high diversity.Totally 83 Sequence Types(STs)were isolated,including some highly human related STs(ST 410,ST 131).There was a certain correlation between STs and host specific of E.coli.Dogs or cats carried some STs specifically.Some STs were carried jointly by two kinds of pets.There was a correlation between drug resistance and STs.Drug resistance rate of different STs was significantly different.However,the antimicrobial resistance distribution of E.coli is polymorphic,and the E.coli genotype or STs could be used as an indicator of antimicrobial resistance potiential.3.Antimicrobial resistance and genomic characterization of Salmonella from compainion animals:There were 26 Salmonella isolates identified in this study.Research showed that Salmonella from pets were divided into two groups with dramatic differences.The first group has 22 strains from intestinal disease pet samples.All strains of first group were S.Dublin and ST 10,carrying the plasmids IncFIIS,IncA/C2 and IncXl.The plasmids carried by these isolates were resistant to most of the tested antimicrobials.The second group has four strains from a healthy dog.These four isolates of second group were S.Typhimurium and ST19,which carries the plasmids IncFIBS,IncFIIS,IncI1 and IncQ1.These isolates were more sensitive than that of isolates in the first group.There is a statistically significnat association between antimicrobial-resistant genes and individual antimicrobial-resistant phenotype among 26 Salmonella isolates.Research showed that both E.coli and Salmonella from feline and canine were highly resistant to antimicrobials.The use of antibiotics would significantly increase the drug resistance of intestinal flora.We need select appropriate antibiotics and use carefully in clinical treatment.This study has provided some essential knowledg for understanding the pathogen spectrum and antimicrobial resistance pattern of compainion animals in certain areas of Hangzhou city,and suggested important implications for clinical rational antibiotic use and risk awareness of zoonotic transmission chain from the compainion animals.