志贺菌临床株膜孔蛋白OmpF及调控基因micF介导耐药机制的研究  

Drug resistance mediated by outer membrane porin F （OmpF） and its regulatory gene of micF in Shigella strains

作　　者：张豪杰[1] 孙阳[1] 刘奉云[1] 贾宇驰 祁伟[1] 

机构地区：[1]天津医科大学第二医院感染性疾病研究所,300211

出　　处：《中华微生物学和免疫学杂志》2016年第9期686-691,共6页Chinese Journal of Microbiology and Immunology

摘　　要：目的：研究志贺菌micF基因和膜孔蛋白ompF基因介导的细胞膜耐药机制。方法选取近年分离保存的志贺菌临床株,抗生素药敏试验筛选出多重耐药菌株和非多重耐药菌株, PCR扩增外膜孔蛋白ompF基因,实时荧光定量RT-PCR技术检测两组菌株micF和ompF基因的mRNA转录情况,并测定两组菌株胞内环丙沙星的浓度。结果多重耐药组13株对3类或3类以上抗生素耐药,非多重耐药组8株全敏感或仅对1类、2类抗生素耐药；21株志贺菌ompF检测均为阳性；多重耐药组micF基因相对表达量明显高于非多重耐药组,而ompF基因相对表达量明显低于非多重耐药组,差异有统计学意义；对两者进行相关性分析,r=-0.244,提示micF和ompF之间呈负相关；多重耐药组胞内环丙沙星浓度低于非多重耐药组,且差异有统计学意义。结论膜孔蛋白OmpF减少是志贺菌引起多重耐药的机制之一,micF基因对膜孔蛋白OmpF的表达起负调控作用,多重耐药菌胞内抗生素浓度的降低可能与膜孔蛋白的表达减少有一定关系。Objective To investigate the mechanism of drug resistance mediated by micF gene and outer membrane porin F （ OmpF） in Shigella strains. Methods Shigella strains were isolated from stool samples of patients who presented to the Second Hospital of Tianjin Medical University with acute diar-rhea in 2015. Antibiotic susceptibility test was performed to screen out the multidrug-resistant and non-multi-drug-resistant strains. The ompF gene was amplified by PCR. The micF and ompF genes at transcriptional levels in the two groups of strains were detected by quantitative real-time RT-PCR. Intracellular concentra-tions of ciprofloxacin in the two groups of Shigella strains were measured by automatic microplate reader. Re-sults According to the result of antibiotic susceptibility test, 13 strains that were resistant to 3 or more than 3 antibiotics were classified into the multidrug-resistant group, while the other 8 strains that were sensitive to all antibiotics used in this study or only resistant to 1 or 2 antibiotic were classified into the non-multidrug-re-sistant group. All of the 21 Shigella strains carried the ompF gene. Compared with the non-multidrug-resist-ant strains, the multidrug-resistant strains showed higher expression of micF gene, but lower expression of ompF gene. The differences in micF and ompF genes between the two groups were statistically significant. The result of correlation analysis suggested that there was a negative correlation between micF and ompF genes （r=-0. 244）. The intracellular concentrations of ciprofloxacin in multidrug-resistant strains were low-er than those in the non-multidrug-resistant strains （P〈0. 001）. Conclusion The decreased expression of OmpF was one of the possible mechanisms of multidrug-resistance in Shigella strains. The micF gene was negatively related to the expression of OmpF. Moreover, the decreased intracellular concentrations of cipro-floxacin in multidrug-resistant strains might be related to the decreased expression of OmpF.

关 键 词：志贺菌 抗生素耐药 micF基因 

分 类 号：R446.5[医药卫生—诊断学]