东莞地区耐亚胺培南铜绿假单胞菌oprD基因分析

Analysis of oprD Gene in Imipenem-resistance Clinical Isolates of Pseudomonas Aeruginosa in Dongguan

目的:分析东莞地区oprD基因突变对耐亚胺培南铜绿假单胞菌的作用。方法:收集2016年至2017年东莞地区2家医院的110株耐亚胺培南铜绿假单胞菌临床分离株,PCR法扩增基因oprD并测序分析其序列突变类型。结果:110株确认为亚胺培南耐药菌株,其中3株oprD基因PCR扩增阴性。余107株阳性菌株进行oprD基因测序发现其中7株无突变,84株有框码移位(其中有8株发现携带插入序列ISPpu21、IS1394、ISPpu29以及ISPst2),16株有终止密码子提前出现(形成1个位置提前的新终止密码子进而引起其肽链异常),基因突变率高达90.91%。结论:广东东莞地区铜绿假单胞菌oprD基因突变导致其氨基酸改变或(和)移码突变,影响oprD与IMP结合是本组铜绿假单胞菌对亚胺培南耐药的主要机制。

Objective: To analyze the mechanism of imipenem resistance in Pseudomonas aeruginosa clinical isolates. Methods: 110 imipenem-resistance Pseudomonas aeruginosa clinical isolates were collected from 2 hospitals of Dongguan between 2016 and 2017, and antibiotic resistance was analyzed using VITEK2 system. PCR was performed to amplify gene oprD. The amplified products were subject to sequencing analysis. Results: 110 strains of bacteria were identified as drug-resistant strains of imipenem, of which 3 were negative for PCR amplification of oprD gene. The oprD gene sequencing of the remaining 107 positive strains showed that 7 of them had no mutation, 84 had frameshift mutations(Eight of them were found to carry insertion sequences ISPpu21, IS1394, ISPpu29 and ISPst2), and 16 with a premature stop codon which is a new termination codon in advance of a position causes its peptide chain abnormalities. The rate of the mutation was 90.91%. Conclusions: oprD gene mutations result amino change and/or frame shift,hampering the binding of imipenem and oprD was the main imipenem resistance mechanism in Pseudomonas aeruginosa in Dongguan, Guangdong Province.