摘要目的 分析2014年北京地区儿童A组链球菌(group A Streptococcus,GAS)超抗原基因谱,探讨其与GAS的emm型别和感染相关疾病的关系.方法 于2014年5-7月在北京市16个区(县)36家哨点医院被临床诊断为猩红热和咽扁桃体炎的儿童患者咽拭子样本中分离到259株GAS.采用Real-time PCR方法检测GAS超抗原基因(speA、speB、speC、speF、speG、speH、speI、speJ、speK、speL、spe、smeZ、ssa);PCR法扩增GAS菌株M蛋白N末端基因片段,产物经测序比对后确定GAS的emm型别.比较不同组间超抗原基因、emm型别分布的差异.结果 259株GAS中,13种超抗原基因的检出率分别为:speA 48.6％ (126株)、speB 99.2％ (257株)、speC 99.2％ (257株)、speF 98.8％ (256株)、speG98.5％ (255株)、speH 43.6％ (113株)、speI 46.3％ (120株)、speJ 49.0％ (127株)、smeZ 99.2％ (257株)、ssa98.5％ (255株),speK、speL、speM均未检出,共观察到11种超抗原基因谱(A～K).超抗原基因speA、speJ在emm1型GAS中检出率分别为94.2％ (113/120)、95.0％(114/120),高于在emm12型GAS中的检出率(均为5.6％,7/124),差异有统计学意义(x2值分别为191.20、194.80,P值均＜0.001);超抗原speH、speI在emm12型GAS中检出率分别为83.9％(104/124)、88.7％(110/124),高于emm1型GAS的检出率[3.3％(4/120)、4.2％(5/120)],差异有统计学意义(x2值分别为160.30、174.90,P值均＜0.001).致猩红热和致咽扁桃体炎病例GAS分离株的超抗原基因、emm型别分布差异均无统计学意义(P＞0.05).结论 2014年北京市儿童来源GAS的超抗原基因speB、speC、speF、speG、smeZ和ssa的检出率较高,未检测到超抗原基因speK、speL、speM;超抗原基因分布与GAS的emm型别密切相关;未发现超抗原基因及emm型别在致咽扁桃体炎和致猩红热菌株间的分布差异.

abstractsObjective To investigate superantigen gene profiles of group A Streptococcus (GAS) isolated in Beijing pediatric patients in 2014, and to explore the the relationship between superantigen gene profiles with emm types, and GAS infections with diseases.Methods A total of 259 GAS strains were isolated from pediatric patients clinically who diagnosed with scarlet fever and pharyngitis from 36 hospitals in Beijing from May to July, 2014.The Superantigens genes of strains were performed by Real-time PCR (speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, ssa).PCR amplification of GAS strain M protein N gene segments were carried ort;products after sequencing comparison were analyzed to determine the GAS types of emm.The differences in distributions of superantigen genes and emm types of GAS isolates were compared between subgroups.Results Among the 259 GAS strains, the detection rates of 13 superantigens were as the following: speA 48.6％ (126), speB 99.2％ (257), speC 99.2％ (257), speF 98.8％ (256), speG 98.5％ (255), speH 43.6％ (113), speI 46.3％ (120), speJ 49.0％ (127), smeZ 99.2％ (257) and ssa 98.5％ (255), respectively, however, speK, speL, and speM were not found.Eleven superantigen gene profiles in all were observed (A-K).The percentage of emm1 strains harbored spe A and speJ were 94.2％ (113/120), 95.0％ (114/120), respectively, which were significantly higher than those of emm12 strains (5.6％(7/124), 5.6％ (7/124),respectively;x2=191.20,194.80,P＜0.001).The percentage of emm12 strains harbored speH and speI were 83.9％ (104/124), 88.7％ (110/124), respectively, which were significantly higher than those of emm1 strains(3.3％ (4/120), 4.2％ (5/120), respectively;x2=160.30,174.90, P＜0.001).The superantigen genotypes of GAS strains and emm types, which were isolated from scarlet fever and pharyngitis cases, were not significant different (P＞0.05).Conclusion The GSA strains isolated in Beijing pediatric patients in 2014, the relevance ratio of speB, speC, speF, smeZ, speG, ssa were higher than others, while speK, speL, and speM were no detected in any GAS strains.The superantigen genes appeared to be associated with the emm type.Furthermore, emm type distribution and superantigen genes were not different between scalet fever and pharyngitis.