产超广谱β-内酰胺酶的大肠埃希菌和肺炎克雷伯菌相关耐药基因监测

Surveillance on Drug Resistance Genes Associated with Extended-spectrum Beta-lactamases in Escherichia coli and Klebsiella neumoniae

目的了解产超广谱β-内酰胺酶(ESBLs)菌中常见的β-内酰胺酶基因的分布情况。方法采用聚合酶链反应(PCR)检测了77株产ESBLs的大肠埃希菌和肺炎克雷伯菌中TEM、SHV和CTX-M等三种β-内酰胺酶基因,并进行了DNA测序。结果 50株产ESBLs的大肠埃希菌中,41株TEM基因阳性(82.0%),7株SHV基因阳性(14.0%),16株CTX-M基因阳性(32.0%),21株菌两种以上基因型同时阳性。27株产ESBLs的肺炎克雷伯菌中,21株TEM基因阳性(77.8%),24株SHV基因阳性(88.9%),3株CTX-M基因阳性(11.1%),16株菌两种以上基因型同时阳性。结论产ESBLs的大肠埃希菌和肺炎克雷伯菌中携带多种β-内酰胺酶基因,且以TEM和SHV型较为流行。

Objective To investigate the distribution of resistance genes associated with ESBLs in Escherichia coli and Klebsiella pneumoniae. Methods Polymerase chain reaction（PCR） was used to detect three kinds of β-lactamase genes（TEM,SHV,and CTX-M） in 77 ESBLs producing strains,including Escherichia coli and Klebsiella pneumoniae.The PCR products were sequenced by DNA sequencer. Results Among 50 strains producing ESBLs in Escherichia coli,there were 41 strains positive for the TEM gene positive for the（82.0%）,7 strains positive for the SHV gene（14.0%）,and 16 strains positive for the CTX-M gene（32.0%）.Two or more genotypes were simultaneously isolated from 21 strains.Among 27 strains producing ESBLs in Klebsiella pneumoniae, TEM gene was positive in 21 strains（77.8%）,SHV gene was positive in 24 strains（88.9%）,and CTX-M gene was positive in 3 strains（11.1%）.Two or more genotypes were simultaneously isolated from 16 strains. Conclusions ESBLs producing strains in Escherichia coli and Klebsiella pneumoniae have carried out various kinds of beta-lactamase resistance genes,however,TEM and SHV genotypes are prevalent.