上海地区大环内酯类抗生素耐药肺炎链球菌的遗传学分析

目的 了解上海地区肺炎链球菌中大环内酯类抗生素高耐药菌株的同源性.方法 采用脉冲场凝胶电泳(PFGE)方法对47株临床分离大环内酯类抗生素耐药肺炎链球菌(MRSP)进行同源性分析,并运用多位点序列分型(MIST)对其中6株多重耐药MRSP进行分子遗传学分析,结合血清分型推测其与国际流行克隆株的关系.结果 上海地区ermB和mefE基因阳性大环内酯类抗生素高耐肺炎链球菌中存在流行克隆A型(45%)、B型(17%).PFGE图谱A型的6株多重耐药MRSP菌株都属于亚洲流行克隆CC236(Taiwan19F-14 clone).上海地区发现一个新的MIST型别ST2116(15-16-19-15-6-20-125),推测其由CC236经基因水平交换进化而来.结论上海地区大环内酯类高耐肺炎链球菌的快速增加部分是由于耐药克隆株的播散所致.

The evolution and dissemination of macrolide-resistance Streptococcus pneumoniae in Shanghai

Objective To determine the genetic background and evolutional route of macrolideresistance Streptococcus pneumoniae(MRSP)strains in Shanghai.Methods Forty-seven MRSP clinical isolates were genotyped by pulse field gel electrophoresis(PFGE)to detect the donal relationship of therm.Serotyping and muhilocus sequence typing(MIST)on 6 multi-resistant strains wag used to investigate the evolutional relationship between serum types and international epidemic strain among MRSP strains in Shanghai.Results There were 2 epidemical clones(type A 45%,type B 17%)in MRSP clinical isolates containing both the ermB and the mefE genes in Shanghai.MIST analysis showed that all 6 multi-resistant strains whose PFGE pattern was A type belonging to Asia clonal complex-CC236(Taiwan19F-14 clone).There was a novel ST-ST2116,which might derived from CC236 due to the recombination with alldic change.Conclusion,The high prevalence of erythromycin-resistant Streptococcus pneumoniae containing both the ermB and the mere genes in Shanghai is partly due to the clonal spread of a few mtdtidrng-resistant clones.