摘要
目的筛查大肠埃希菌与肺炎克雷伯菌膜孔蛋白基因情况,分析其与耐药的关系。方法随机抽取2008—2010年耐3代头孢菌素(头孢他啶)的大肠埃希菌72株和肺炎克雷伯菌57株,56株头孢他啶敏感的大肠埃希菌和肺炎克雷伯菌为对照组;三维试验确定细菌头孢菌素β-内酰胺酶(AmpC酶)的产生情况;超广谱β-内酰胺酶(ESBL)确证试验检测细菌产ESBL的情况;多重聚合酶链反应(PCR)扩增AmpC基因和膜孔蛋白ompF、ompk35、ompk36基因;纸片扩散法检测抗菌药物的敏感性。结果 72株大肠埃希菌中,14株产AmpC酶,23株产ESBL,3株膜孔蛋白基因缺失;57株肺炎克雷伯菌中,13株产AmpC酶,19株产ESBL,5株膜孔蛋白缺失,膜孔蛋白缺失株4代头孢均出现耐药。结论我院大肠埃希菌和肺炎克雷伯菌对头孢类抗生素的耐药机制主要是产AmpC酶和ESBLs,同时膜孔蛋白基因的缺失会造成耐药程度增高。
Objective To investigate the porin expression in AmpC β-lactamase isolates of Escherichia coli and Klebsiella pneumonia and analyze the resistant mechanism.Methods We select 129 Escherichia coli（ECO）and Klebsiella pneumonia（KPN） isolated from 2008 and 2010 that were resistant to 3rd generation cephalosporin（ceftazidime）.Fifty-six ceftazidime susceptible ECO and KPN were used as controls.Three-Dimensiona test was used for the detection of AmpC β-lactamase,multiplex polymerase chain reaction（PCR） was used for the detection of genotype and standard disc diffusion method were used for the detection of the sensitivity.Results Among the 72 ECO,14 produced AmpC enzymes,23 had ESBLs and 3 lack of porin genes.Among the 57 KPN,13 produced AmpC enzymes,19 had ESBLs and 5 were lack of porin genes.The isolates without the porin expression are also resistant to 4th generation cephalosporin.Conclusion The main mechanism of cephalosporin resistance is the production of AmpC and ESBL,and lack of porin will increase the resistanct degree.
