Isolation And Identification Of Escherichia Coli And Enterococcus From Rabbit And Study On Their Resistance To Commonly Uesd Antibiotics

In order to understand the drug resistance of E.coli and Enterococcus in rabbit feces in Chengdu,fresh feces were collected from rabbit farms,and the isolation,culture and identification of E.coli and Enterococcus were performed and the main drug resistance genes of β-lactams,quinolones,and tetracyclines were detected in multidrug-resistant strains according to the drug resistance phenotype of the tested strains.The results are reported below:1.A total of 247 samples were collected and identified by differential culture and16 S r RNA sequencing.A total of 75 strains of Escherichia coli(isolation rate 30.36%)and 210 strains of Enterococcus(isolation rate 85.02%)were isolated,all of which had typical culture characteristics.The results of statistical analysis showed that the target bacteria could be isolated from both rabbit farms,of which the isolation rate of enterococci was higher than that of E.coli,suggesting that enterococci may be the dominant bacteria in feces.2.The resistance phenotype analysis(K-B method)and minimum inhibitory concentration(MIC)of gentamicin GM,ampicillin AMP,doxycycline DOX,amoxicillin-clavulanic acid AMC,enoxacin ENR and florfenicol FFC were determined in 75 strains of E.coli and 210 strains of Enterococcus.The results showed that the resistance rates of E.coli isolates to the test drugs were 72%(54/75)for amoxicillin,53.33%(40/75)for ampicillin,26.67%(20/75)for enrofloxacin,26.67%(20/75)for amoxicillin-clavulanic acid,and 100% for polymyxin B.Among them,the proportion of triple(FFC-DOX-GM)resistant bacteria was the highest,16%(12/75),35 strains of multi-drug resistant bacteria,accounting for 46.67%(35/75),suggesting that multi-drug resistance has been more serious,which has potential risks and threats for breeders and as food animals.It is recommended to increase the resistance status of E.coli of rabbit origin.In case of diseases,more sensitive drugs should be selected for treatment to avoid the wide spread of drug resistance;the resistance of enterococcal isolates to the test drugs: polymyxin B 100%(210/210),penicillin 66.67%(140/210),high-level gentamicin 30.47%(64/210),amoxicillin-clavulanic acid,flufenicol,empagliflozin and ampicillin resistance was 0.There were 40 strains of multi-drug resistant bacteria,accounting for 19.05%(40/210),suggesting that the drug resistance rate of enterococci in rabbit farms is still relatively low at present,which may be that the detection drugs have not involved other drug resistance.3.The related resistance genes of 35 strains of multi-drug resistant E.coli and 40 strains of multi-drug resistant enterococci were analyzed.The detection rates of tetracycline resistance genes tet A,tet B and tet M were the highest,94.29%(33/35),25.71%(9/35)and 2.9%(1/35),respectively,followed by the detection rate of quinolone resistance gene qnr S was 71.43%(25/35),and the detection rate of fluorophenicol resistance gene flo R was the lowest,57.14%(20/35),indicating that40 strains of enterococci showing multi-drug resistance to the selected drugs were detected for 7 resistance genes in 3 categories.The detection rate of tetracycline resistance genes tet M was the highest,with a detection rate of 25%(10/40)tet A and tet B.The detection rates of fluorophenicol resistance genes fex A and flo R were 10%(4/40)and 7.5%(3/40),respectively.No quinolone resistance genes were detected.