Drug Sensitivity Test Of Enterococcus From Feline And The Analysis Of Whole Genome Sequencing Of Multi-drug Resistant Strain Jay1

Enterococci,as the important conditional pathogens,is widely distributed in the gastrointestinal tract and natural environment of humans and animals.It has shown varying degrees of drug resistance to commonly used antimicrobial agents,which not only causes difficulties for veterinary clinical anti-infective treatment,but also poses a serious threat to public health and safety.Studies have shown that Enterococcus faecalis and Enterococcus faecium can be used as repositories of drug resistance genes,which is conducive to the horizontal transmission of drug resistance genes,but there are few reports on the drug resistance of Enterococci from feline and the genetic environment of drug resistant strains.For this reason,this study intends to study the drug-resistant phenotype and genotypes of feline-derived Enterococci in some pet hospitals in Changchun,in order to lay a foundation for the further study of the mechanism of feline-derived Enterococci drug resistance and the scientific and rational use of antibiotics in veterinary clinic.The main contents are as follows:1.Isolation,identification and drug sensitivity test of Enterococci from felineEnterococci were isolated and identified from 240 fecal samples collected from some animal hospitals in Changchun.46 strains of Enterococci(28 strains of Enterococcus faecalis and 18 strains of Enterococcus faecium)were isolated by Gram staining and 16S r DNA sequencing analysis.The drug sensitivity of the isolates was tested,and the results showed that the drug resistance rates of the isolates to gentamicin,tetracycline and erythromycin were 89.1%,71.7%and 73.9%,respectively.While the isolates also showed varying degrees of drug resistance to penicillin G,ciprofloxacin,norfloxacin,levofloxacin and florfenicol,and the resistance rates were 34.8%,23.9%,23.9%,23.9%and 8.7%,respectively.Some of the isolates showed multiple drug resistance,of which triple and quadruple resistance were the most,and the isolates were only sensitive to linezolid and vancomycin.2.Detection and analysis of drug resistance genes and targets of Enterococci from felineThe results of drug resistance gene detection showed all the isolates carried bla _TEM and aad D resistance genes,which could mediate drug resistance to?-lactam and aminoglycosides,while some isolates carried drug resistance genes such as vat E,mex I and tet(O),which could mediate drug resistance to macrolides and tetracyclines.The quinolone resistance target determining regions of 11 fluoroquinolone resistant strains were detected.The results showed that there were three different mutation types.A amino acid substitution in gyr A(V85I)was found in 10 strains.At the same time,the multi-drug resistant strain Jay1 was screened,which carried drug resistance gene cassette,including bla P1b,dfr A16,aad A1,aac(6')-Ib-cr,cat B3,cml A1 and aar-3,which could mediate the resistance to trimethoprim,?-lactam,aminoglycosides and so on.3.The whole genome sequencing and analysis of drug resistance environment of the multi-drug resistant strain Jay1The whole genome sequencing of the multi-drug resistant strain Jay1 was sequenced and analyzed by ONT sequencing platform.The results showed that the Jay1 genome contained 25drug resistance genes,13 genomic islands and 3 plasmids.There was a 15kb multi-drug resistance gene cluster and a novel transferable element IME,on the plasmid Contig00003.This structure carries three drug resistance genes(erm B,Aph(3')-IIIa and dfr G),which could mediate the resistance to macrolides,aminoglycosides and trimethoprim,respectively.At the same time,the mobile element may be transferred horizontally by T4SS,which has the risk of drug resistance gene transmission.In summary,46 strains of Enterococci were successfully isolated from feline feces.The isolates exhibited highly resistance to antibiotics such as gentamicin,tetracycline,erythromycin,penicillin G,ciprofloxacin,norfloxacin and levofloxacin.In addition,the whole genome sequencing of the multi-drug-resistant strain Jay1 showed that the mobile element carried by plasmids played an important role in mediating common clinical antibiotic resistance and horizontal transfer of drug-resistant genes,which should be paid enough attention to.The above results could provide experimental basis for preventing and treating Enterococcal infection and guiding clinical drug use in pets.