百日咳鲍特菌红霉素耐药性及耐药相关分子特征分析

Resistance to Erythromycin and Molecular Characteristics of Bordetella pertussis

目的分析百日咳鲍特菌(Bordetella pertussis,Bp)红霉素耐药性并对其耐药相关分子特征进行检测。方法对分离自西安市2014年百日咳报告病例中的Bp通过E-Test检测其红霉素耐药性,通过聚合酶链反应(PCR)和PCR-测序方法分别检测可能出现的耐药基因及耐药相关位点改变。结果 10株Bp临床株分布于西安市6个区县,对红霉素的最小抑菌浓度(MIC)均>256μg/ml,所有菌株都出现23S rRNA基因的A2047G突变,未见其他耐药基因及位点改变。结论西安市的红霉素耐药Bp已较为普遍,23S rRNA基因的A2047G突变可能是其最主要的耐药机制。应在百日咳监测的同时加强病原的抗生素耐药性监测及耐药相关分子的检测。

Objective To determine susceptibilities to erythromycin and the molecular characteristics of Bordetella pertussis（Bp）.Methods Ten Bp strains,isolated from reported pertussis cases in Xi＇an in 2014,were tested by E-Test methods to determine minimal inhibitory concentrations（MIC） to erythromycin.Polymerase chain reaction（PCR） and PCR-sequencing methods were used to identify resistant genes and relative changes such as deletions,insertions or mutations.Results 10 isolated strains were distributed in 6 counties of Xi＇an.The MIC to erythromycin for all strains was 256μg/ml,and these strains were defined as erythromycin resistant strains.A genetic mutation occurred at the A2047G site in the 23 S rRNA gene of all strains;other relative resistant genes or changes were not seen.Conclusions Erythromycin resistant Bp stains were prevalent in Xi＇an.The common resistance mechanism was mutation of A2047G in the 23 S rRNA gene of Bp.We suggest strengthening pertussis surveillance,especially for erythromycin resistant Bp.