膜孔蛋白在产AmpC酶大肠埃希菌和肺炎克雷伯菌中的作用

The significance of porin in the AmpC beta-lactamase isolates of Escherichia coli and Klebsiella pneumonia

目的调查产头孢菌素β-内酰胺酶(AmpC酶)的大肠埃希菌和肺炎克雷伯菌膜孔蛋白的表达情况,分析其耐药机制。方法收集2003至2009年间产AmpC酶的大肠埃希菌和肺炎克雷伯菌65株,三维试验确定细菌AmpC酶的产生情况,多重聚合酶链反应(PCR)扩增ampC基因和膜孔蛋白ompF、ompK35、ompK36基因,实时定量逆转录RT-PCR检测膜孔蛋白的相对表达量,纸片扩散法检测抗菌药物的敏感性。结果 32株大肠埃希菌中,14株(43.75%)膜孔蛋白ompF转录水平下调;33株肺炎克雷伯菌中,17株(51.52%)膜孔蛋白ompK35、ompK36转录水平下调。结论在产AmpC酶的大肠埃希菌和肺炎克雷伯菌中膜孔蛋白的低表达是造成耐药不可忽视的因素之一。

Objective To investigate the expression of the porin in AmpC beta-lactamase isolates of Escherichia coli and Klebsiella pneumonia and analyze the resistant mechanism.Methods 65 strains of Escherichia coli and Klebsiella pneumonia collected from 2003 to 2009 were determined.Three-dimension test was used for the detection of AmpC beta-lactamase,and multiplex polymerase chain reaction（PCR） was used for the amplification of ampC genotype and porin ompF,ompK35 and ompK36 genes.The real-time quantitive reverse transcription（RT）-PCR was used for the detection of the expression level of porin,and the standard disc diffusion method was used for the detection of the antibiotic agent sensitivity.Results Among the 32 strains of Escherichia coli,14 isolates（43.75%） had low ompF transcription level,and 17（51.52%） of 33 Klebsiella pneumonia had low ompK35 and ompK36 transcription level.Conclusions The low expression of porin is an important mechanism of antibiotics resistance among Escherichia coli and Klebsiella pneumonia.