昆明地区多重耐药鲍曼不动杆菌耐药特征及同源性分析

Drug resistance and homology analysis of multi-drug resistant Acinetobacter baumannii in Kunming

目的研究昆明地区多重耐药鲍曼不动杆菌(MDRAB)耐药流行特征,通过分子流行病学调查明确菌株间亲缘关系,在丰富该地区当前MDRAB耐药数据的同时为临床制订合理有效的用药策略提供依据。方法收集2018年1月至2020年12月昆明地区两家三级甲等医院(简称医院甲、医院乙)临床分离的非重复MDRAB菌株共92株,采用微量肉汤稀释法和纸片扩散法检测MDRAB对临床常用抗菌药物的敏感性,采用聚合酶链反应扩增7种β-内酰胺酶耐药基因,同时对92株MDRAB进行分子分型,分析菌株同源性关系。结果92株MDRAB对所检测抗菌药物耐药程度均较高,其中医院甲对氨基糖苷类和喹诺酮类抗菌药物(除环丙沙星)耐药率普遍高于医院乙,而相对于医院乙检出的MDRAB对替加环素14.3%的耐药率,医院甲尚未检测到耐药发生。耐药基因检测结果显示,两家医院检出率较高的是OXA-23、TEM和ADC基因,未检出SHV、IMP、VIM、OXA-58基因。测序及比对结果显示,92株MDRAB包括12个序列型(ST),两家医院主要型别有所不同,医院甲以ST208型(58.0%)为主要型别,而医院乙以ST368型(31.0%)为主要型别。结论临床分离鲍曼不动杆菌耐药现象严重,对各种类型抗菌药物普遍耐药,但对替加环素敏感性较好;携带多种β-内酰胺酶相关基因是该地区MDRAB对β-内酰胺类抗菌药物高耐药的重要原因之一;两家医院存在不同ST的MDRAB克隆传播。

Objective To study the epidemic characteristics of multi-drug resistant Acinetobacter baumannii(MDRAB)in Kunming,clarify the genetic relationship between strains through molecular epidemiological investigation,enrich the current MDRAB resistance data in this region,and provide a theoretical basis for clinical formulation of reasonable and effective drug use strategies.Methods From January 2018 to December 2020,a total of 92 non repetitive MDRAB strains were collected from two third grade first class hospitals in Kunming(hospital A and hospital B for short).The sensitivity of MDRAB to commonly used antibiotics was detected by microdilution method and disk diffusion method,and 7 kinds ofβ-lactamase resistance genes were amplified by polymerase chain reaction.At the same time,92 strains of MDRAB were genotyped,and the homology of the strains was analyzed.Results A total of 92 strains of MDRAB were highly resistant to the detected antibiotics.Among them,the resistance rate of hospital A to aminoglycosides and quinolones(except for ciprofloxacin)was generally higher than that of hospital B.Compared with the 14.3%resistance rate of MDRAB detected in hospital B to tegacyclin,MDRAB detected in hospital A had not detected drug resistance.The results of drug resistance gene detection showed that OXA-23,TEM and ADC genes had high detection rates in the two hospitals,and SHV,IMP,VIM and OXA-58 genes were not detected.Sequencing and comparison results showed that 92 strains of MDRAB were divided into 12 sequence types(ST),the main types of the two hospitals were different,ST208(58.0%)was the dominant type in hospital A and ST368(31.0%)was the dominant type in hospital B.Conclusion The drug resistance of Acinetobacter baumannii isolated from Kunming is serious,and it was generally resistant to various types of antibiotics,but it maintains good sensitivity to tegacyclin.Carrying multiple drug resistance genes is one of the important mechanisms of MDRAB resistance in this region.There are different types of MDRAB clonal transmission in the two hospitals.