Drug Resistance of 2277 Strains of Escherichia coli and Detection of TEM and SHV Type ?-Lactams Gene / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To investigate drug resistance of Escherichia coli,especially the prevalence of the genes for TEM and SHV type ?-lactams in ESBLs-producing E.coli. METHODS A total of 2277 strains of E.coli collected in our hospital from Jan 2006 to Nov 2008 were analyzed for drug resistance to 21 kinds of antibiotics such as aminoglycoside,?-lactams and quinolones using VITEK-32 GNS-145 or GNS-448 card following GNI + for identification.PCR methods were used to analyze TEM and SHV type ?-lactams genes in 36 strains of E.coli with ESBLs so as to study their prevalence. RESULTS From them 1025 strains of E.coli were found positive for ESBLs,with a positive rate of 45.0%.Drug resistance rates were 83.0%,74.0%,52.0%,52.0%,29.1%,27.8%,16.5%,47.0%,31.0%,54.5%,53.0%,56.8%,10.0%,53.9%,38.5%,5.0%,4.0%,5.0% and 5.0%,respectively,for ampicillin,ampicillin/sulbactam,cefazolin,cefuroxime,aztreonam,cefepime,ceftazidime,ceftriaxone,cefotaxime,ciprofloxacin,levofloxacin,gentamicin,amikacin,tobramycin,Co-trimoxazole,nitrofurantoin,piperacillin /tazobactam,cefoperazone/sulbactam and cefoxitin.None was found resistant to imipenem or meropenem.Twenty-five and 14 strains of E.coli were found positive for TEM and SHV genes,respectively(69.4% and 38.9%). CONCLUSIONS Drug resistance of E.coli is severe.The local E.coli with ESBLs shows high positive rates of TEM and SHV genes,which play an important role in its severe drug resistance.