Antibiotics resistance of extended-spectrum β-lactamases-producing Escherichia coli and Klebsiella pneumoniae causing urinary tract infections

OBJECTIVE To analyze the drug resistance of extended spectrumβ-lactamase(ESBL)-producing Escherichia coli and Klebsiella pneumoniae causing urinary tract infections so as to guide the reasonable clinical use of antibiotics.METHODS A total of 1019copies of midstream urine specimens were collected from Jan 2009 to Jul2010,then the automated microbial analyzer(VITEK-2 Compact)was employed to perform the bacteriologic identification and the drug susceptibility testing,and the ESBL-prodESBL-producingucing bacteria were detected by using the double disc recommended by NCCLS and the phenotypic confirmatory test.RESULTS Totally 254 strains of gram-negative bacilli were isolated from 1019copies of specimens with the positive rate of 24.9%,among which there were 127(50.0%)strains of E.coli and 74(29.1%)strains of K.pneumonia;there were 50(39.4%)strains of ESBL-producing E.coli and 33(44.6%)strains of K.pneumoniae.The ESBL-producing strains and the non-ESBL-producing strains showed low drug resistance to cefotetan,imipenem,meropenem,and piperacillin/tazobactam,with the drug resistance rate less than 24.2%;the ESBL-producing strains were multidrug-resistant toβ-lactams antibiotics,aminoglycosides,quinolones and sulfa drugs;the non-ESBL-producing E.coli showed intermediary or resistance;the non-ESBL-producing K.pneumonia showed high drug resistance to ampicillin and piperacillin,with the drug resistance rate more than 97.6%,while the strains showed low resistance to all the antibiotics except for cefuroxime axetil.CONCLUSIONThe drug resistance rate of the ESBL-producing strains causing urinary tract infections is higher than that of the non-ESBL-producing strains,and the strains are multidrug-resistant,which is the cause of failure of clinical drug therapy.It is of great significance to the control of drug resistant strains and the clinical treatment to strengthen the monitoring of the ESBL-producing strains and use antibiotics based on the drug susceptibility testing.