鲍曼不动杆菌OXA-23型碳青霉烯酶相关耐药基因分析

Analysis of OXA-23 carbapenemase-encoding drug resistance correlated gene of Acinetobacter baumannii

目的:分析鲍曼不动杆菌的耐药性及其产碳青霉烯酶的类型。方法:收集南京医科大学第一附属医院对碳青霉烯类药物中介或耐药的鲍曼不动杆菌22株及敏感菌3株,用琼脂纸片扩散法(KB法)及肉汤稀释法测定最低抑菌浓度(MIC),用聚合酶链反应(PCR)检测分析其耐药基因。结果:22株细菌均为多重耐药株,PCR检出22株耐药菌株中18株携带OXA-23基因,未能检出OXA-24基因,3株敏感株均未检出OXA-23及OXA-24基因,PCR产物纯化后测序表明与鲍曼不动杆菌(AY795964.1)blaOXA-23基因序列100%同源。结论:携带OXA-23型碳青霉烯酶基因的鲍曼不动杆菌对临床常用抗菌药的耐药率高,其编码基因为blaOXA-23。

Objective：To investigate antibiotic resistance and carbapenemase genotype in Acinetobacter baumannii. Methods： Twenty-two strains of Acinetobacter baumannii resistant to carbapenem and 3 strains susceptible to carbapenem were collected. Their MIC were done by Kribry-Bauer methods and microbroth dilution. The genes were amplified by polymerase chain reaction（PCR）, and the PCR products were sequenced. Results：The 22 strains were multi-drug resistance. OXA-23 gene was identified in 18 of the 22 strains, but the gene was not identified in 3 susceptible strains. OXA-24 was not identified in either resistant or susceptible strains. The sequenced results were absolutely homology with blaOXA-23 gene. Conclusion：Production of OXA-23 in A cinetobacter baumannii is one of the molecular mechanisms responsible for carbapenem resistance, and the code gene was blaOXA-23.