Isolation and identification,phylogenetic clustering and drug resistance analysis of goose-derived Escherichia coli in Xinyang area
In order to understand the phylogenetic clustering,virulence gene carrying and drug resistance of goose-derived E.coli in Xinyang area,in the experiment,isolation and identification of E.coli were carried out from the liver,spleen and other tissues of 46 suspected E.coli infected geese sent by some farmers in Xinyang area;the isolated strains were carried out for systematical clustering,virulence gene detection,drug resistance analysis,and drug resistance gene detection.The results showed that a total of 23 strains of E.coli were isolated and named GE1-GE23.The 23 strains of E.coli were distributed in a certain proportion of the four phylogenetic groups,including 3 strains in group A(GE11,GE12,GE19,accounting for 13.04%),3 strains in group B1(GE4,GE15,GE23,accounting for 13.04%),9 strains in group B2(GE1,GE2,GE8,GE10,GE14,GE16,GE17,GE20,GE21,accounting for 39.13%),and 8 strains in group D(GE3,GE5,GE6,GE7,GE9,GE13,GE18,GE22,accounting for 34.78%).The detection rates of marA,fimC,fyuA,iroN,iss,hlyF,ompT,iutA and irp2 genes in 23 strains of Escherichia coli were 100%,95.65%,52.17%,47.83%,43.48%,39.13%,34.78%,30.43%and 17.39%,respectively.The 23 isolates had the highest resistance rate to amoxicillin/clavulanate potassium,which was 65.22%.Then sulfamethoxazole/trimethoprim,doxycycline,florfenicol,polymyxoxin B,ceftiofur,levofloxacin and ciprofloxacin were followed,and the drug resistance rates were 56.52%,52.17%,47.83%,34.78%,17.39%,17.39%and 8.70%,respectively.The 23 isolates had the highest susceptibility rate to imipenem,which was 100%.Then amicana,streptomycin,neomycin,ciprofloxacin and levofloxacin,cefotaxifur,florfenicol,polymyxin B,doxycycline,sulfamethoxazole/trimethoprim were followed,and the sensitivity rates were 82.61%,82.61%,47.83%,47.83%and 47.83%,34.78%,26.09%,21.74%,17.39%and 8.70%,respectively.Among the 23 isolates,12 strains showed multi-drug resistance,of which one strain was 6-resistant and one was 7-resistant,each accounting for 4.35%.There were three 4-resistant and 5-resistant strains,each accounting for 13.04%;there were four 3-resistant strains,accounting for 17.39%.In the detection of drug resistance genes,the detection rate of tetA gene was the highest,which was 82.61%;then followed by folR,sul2,aadA,blaTEM,blaCTX-M,aphA1,clmA,sul3,sul1 and aphA2,which were detected at 73.91%,65.22%,56.32%,52.17%,47.83%,47.83%,43.48%,26.09%,13.04%and 13.04%,respectively.The results indicated that the B2 and D groups of E.coli from goose in Xinyang area accounted for a large proportion,carrying a variety of virulence genes and drug resistance genes,and most of them showed multi-drug resistance.