Analysis on the Antimicrobial Susceptibilities and the Prevalence of ESBLs Encoding Genes of Escherichia Coli Isolates Collected from Blood / 现代检验医学杂志

ABSTRACT

Objective To analyze the susceptibilities of Escherichia coli isolates collected from blood and the prevalence of ESBLs encoding genes.Methods A total of 121 Escherichia coli isolates collected from blood during 2012 were analyzed for antimicrobial susceptibilities by software of WHONET 5.6,the production of ESBLs was confirmed by confirmatory pheno-typic testing,PCR and DNA sequence were further implemented to analyze the ESBLs-encoding genes.Results 121 E.coli isolates displayed high resistance towards broad spectrum penicillin and 2nd or 3rd generation cephalosporins,levofloxacin and cotrimoxazole,with the resistance rates being more than 40%,susceptibilities to imipenem,piperacillin/tazobactam,ami-kacin were observed,with the resistance rates to be less than 12%,86(88.7%)out of 121 isolates were found to produce ESBLs.Among them,59.5% (72),38.8% (47)and 4.1% (5)were confirmed to carry blaCTX-M,blaTEM and blaSHV genes.Additionally,2(1.7%)isolates carried all the genes detected,30(24.8%)isolates carried both of blaCTX and bla-TEM,1(0.8%)isolate carried both of blaSHV andblaTEM.Conclusion Most of the E.coli isolates from the blood culture in Nanjing Gulou Hospital produce ESBLs,and displayed resistance towards most of the penicillins,cephalosporins and sin-gle amide antimicrobial agents should be chosen according to susceptibility results.