Analysis of antimicrobial resistance and β-lactam-producing in multiply antimicrobial-resistant Escherichia coli

Objective To investigate the relationship between β-lactam-producing multiply Escherichia coli and β-lactam antibiotics resistance to provide reference for using antimicrobial agent reasonablely.Methods Amylometric method,three dimensional test and slip diffusion test were proceeded for detecting penicillinase,metallo-β-lactam antibiotics and superspectrum β-lactam antibiotics respectively,and the antimicrobial susceptibility was determinded by K-B method.Results 125 multiply antimicrobial-resistant Escherichia coli strains were isolated,whose resistant rate to cefalotin,cefuroxime,cefotaxime,ceftazidime,cefepime and cefoxitin was 84.8%,72.0%,56.0%,71.2%,60.8% and 28.0% respectively,which also showed low resistant to sulbactam(12.8%) and tazobactam(15.2%),but high resistant to ampicillin(94.4%),piperacillin(90.4%) and ticarcillin(91.2%).63 (50.4%) ESBLs-producing Escherichia coli strains were isolated,and the resistant rate to polyantibiotic of ESBLs-producing Escherichia coli was higher than that of non-ESBLs-producing Escherichia coli.Conclusion Multiply antimicrobial-resistant Escherichia coli and four erzymes-producing bacteria were resistant to most antibiotics except imipenem and meropenem.The resistant rate of cephalosporins was high,suggesting that cephalosporins are inappsopriate as first line drug except the support from drug sensitive experimental result.