摘要
目的研究我国儿科A群β溶血性链球菌(GAS)临床分离株抗菌药物敏感性情况。方法收集5所儿童医院2005—2006年222株GAS感染的临床菌株,采用琼脂稀释法测定11种抗菌药物的MIC值;诱导试验分析大环内酯类抗生素耐药表型;PCR检测大环内酯类抗生素耐药基因ermB、ermTR和mefA。结果分离株对大环内酯类抗生素和克林霉素耐药率在93.69%～98.65%,MIC90>512mg/L;对四环素的耐药率为94.14%;对青霉素、头孢他啶的敏感率高达100%。分离株大环内酯类抗生素耐药以耐大环内酯类、林可酰胺类和链阳性菌素B表型(cMLS)为主,占99.04%,iMLS表型仅2株,未检测到M型;ermB、ermTR和mefA阳性率分别为94.71%、2.89%和0。结论所测儿科GAS感染流行菌株对大环内酯类抗生素和克林霉素耐药率高,主要耐药机制为ermB编码的23SrRNA甲基化酶导致靶位改变,青霉素类和头孢菌素类抗生素是治疗我国GAS感染首选药物。
Objective To investigate the drug resistance of Group A Streptococcus （GAS） isolates from Chinese children. Methods A total of 222 GAS isolates collected from 5 Children＇s Hospitals in China during 2005-2006 were studied. The minimum inhibitory concentrations （MICs） of 11 antibiotics were evaluated by agar dilution method. Double-disc agar diffusion test was used to determine the macrolide resistance phenotype, The genes encoding erythromycin resistance （ermB, ermTR and mefA） were amplified by PCR. Results Among the 222 isolates, the resistance rates to macrolides and clindamycin ranged from 93.69% to 98.65% , with MIC90〉512 mg/L. The resistance rate to tetracycline was 94, 14%, All strains were susceptible to penicillin and ceftazidime. The most common macrolide resistant phenotype was cMIS type （99.04%）. Only two strains were iMLS type, and no M type was detected. The ermB, ermTR and mefA gene was identified in 94.71%, 2.89% and 0 of the strains respectively. Conclusions The results indicate that macrolides resistance is prevalent in the GAS isolates from children in China. The main mechanism of macrolide resistance is 23S rRNA methylation encoded by ermB gene. Penicillins and cephalosporins should be the first choice to treat GAS infections in China.
出处
《中国感染与化疗杂志》
CAS
2008年第5期338-342,共5页
Chinese Journal of Infection and Chemotherapy
基金
国家863项目资助(2006AA02Z417)
关键词
链球菌
大环内酯类
表型
Streptococcus pyogenes
Macrolide
Phenotype
