广东省猩红热患儿酿脓链球菌病原学特征分析

摘要

目的 了解广东省不同时期猩红热患儿酿脓链球菌的病原学特征.方法 对不同时期广东省酿脓链球菌分离株22株进行emm分型、超抗原基因检测、抗生素敏感性分析和PFGE分子分型.结果 酿脓链球菌对头孢噻肟、左旋氧氟沙星和青霉素100％敏感,2000年以后分离的酿脓链球菌对红霉素和克林霉素100％耐药,而2000年以前的菌株只有9.1％(1/11)对这两种药物耐药.22株酿脓链球菌有3个emm型:59.09％ (13/22)为emm12.0型,36.36％ (8/22)为emm6.0型,4.55％ (1/22)为emm1.0型.2011年和1997年分离的酿脓链球菌为emm12.0型,1978年和1986年分离的菌株为emm6.0型,2008年分离的菌株为emm1.0型.超抗原基因speA,speB,speC,speF,speG,speH,smeZ和ssa的检出率分别为:54.55％、100％、100％、100％、100％、54.55％、0％、86.36％,95.45％的菌株同时携带6个超抗原基因.22株酿脓链球菌可分为10种不同的PFGE型别,分成Ⅰ～Ⅲ3个聚集簇,聚集簇Ⅰ由1997年分离的菌株和1株2011年分离的菌株组成,聚集簇Ⅱ由1978年和1986年分离的菌株组成,聚集簇Ⅲ由9株2011年分离的菌株和1株2008年分离的菌株组成.结论 广东省猩红热患儿酿脓链球菌对青霉素敏感,红霉素耐药,emm12.0型为主要emm型,酿脓链球菌的超抗原基因携带率高.%Objective To investigate the etiological characteristics of Streptococcus pyogenes that caused scarlet fever in different periods in Guangdong province.Methods 22 isolates from different periods were analyzed through emm typing,PCR detection for super antigen genes,antibiotic susceptibility test and pulsed-field gel electrophoresis (PFGE).Results All isolates were susceptible to cefotaxim,levofloxacin and penicillin.Streptococcus pyogenes isolated after the year 2000 were 100％ resistant to erythrocin and clindamycin,but the resistant rate for strains isolated before the year 2000 was 9.1％ (1/11).There were 3 emm types indentified from 22 isolates including emm12.0 (59.09％,13/22),emm6.0 (36.36％,8/22) and emm1.0 (4.55％,1/22),which were detected in the isolates from the year 1997 and 2011,from 1978 and 1986,and from 2008,respectively.The positive rates for speA,speB,speC,speF,speG,speH,smeZ,and ssa genes detected by PCR were 54.55％,100％,100％,100％,100％,54.55％,0％,and 86.36％ respectively.Among all strains,95.45％ of the isolates carried 6 superantigen genes simultaneously.Three clusters of 10 PFGE subtypes were identified in 22 isolates.Cluster Ⅰ consisted of all strains from 1997 and one strain from 2011.Cluster Ⅱ consisted of strains isolated from 1978 and 1986.Cluster Ⅲ consisted of nine strains from 2011 and one from 2008.Conclusion S.pyrogenes isolates in Guangdong province were susceptible to penicillin but resistant to erythrocin.emm 12.0 accounted for the majority of the three types and there was a high frequency of super antigen genes.