Detection of AmpC ?-Lactamases and Analysis of Antimicrobial Activity in vitro for Extended Spectrum ?-Lactamases Positive Escherichia coli and Klebsiella pneumoniae
- VernacularTitle:ESBLs阳性大肠埃希菌和肺炎克雷伯菌产AmpC酶的检测与体外抗菌活性分析
- Author:
Wenjun JIN
;
Yonglu HUANG
;
Zhijiang XU
;
Hongwei ZHOU
;
Rong ZHANG
- Publication Type:Journal Article
- Keywords:
Escherichia coli;
Klebsiella pneumoniae;
AmpC enzyme;
Genotype;
Drug resistance
- From:
Chinese Journal of Nosocomiology
2006;0(06):-
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE To detect AmpC ?-lactamases from isolates of extended spectrum ?-lactamases(ESBLs) positive Escherichia coli and Klebsiella pneumoniae,which were isolated from four hospitals in Hangzhou from 2005 to 2006,and to analyze the antimicrobial activity of clinically commonly used antibiotics in vitro.METHODS Amount of 324 ESBLs positive isolates including E.coli and K.pneumoniae were collected from Zhejiang Provincial People′s Hospital;1st Affiliated Hospital of Zhejiang University;2nd Affiliated Hospital of Zhejiang University and Hangzhou Traditional Chinese Medicine Hospital perspectivly.AmpC ?-lactamase was identified by disc screening testing and three dimensional test,and the genotypes of AmpC ?-lactamase were also determined by multiplex polymerase chain reaction(Multi-PCR).Minimal inhibitory concentrations(MICs) of ten clinically commonly used antibiotics were determined by agar dilution for AmpC ?-lactamases positive isolates,and the data were analyzed by WHONET 5.3.RESULTS AmpC ?-lactamase phenotype test revealed that 76 AmpC ?-lactamase positive isolates(23.5%) were identified among 324 ESBLs positive isolates of E.coli and K.pneumoniae from four hospitals in Huzhou.69.7% Of the AmpC ?-lactamase phenotype positive isolates were positively amplified by Multi-PCR.The value of MIC50 for carbapenem was lower 0.25 ?g/ml.We also found four carbapenem-resistant strains in this study.CONCLUSIONS We found that the incidence rate of AmpC ?-lactamase is high among the ESBLs producing E.coli and K.pneumoniae strains in Hangzhou.Carbapenem antibiotics have higher antimicrobial activity than other tested antibiotics.
