Lu Guilan, Zhang Daitao, Zhao Jiachen, Liu Yimeng, Guo Jing, Wu Shuangsheng, Zhang Li, Yang Peng, Wang Quanyi, Peng Xiaomin
Institute of Infectious Disease and Endemic Disease Control, Beijing Centers for Disease Control and Prevention, Beijing 100013, China.
Institute of Infectious Disease and Endemic Disease Control, Beijing Centers for Disease Control and Prevention, Beijing 100013, China; Email:
Zhonghua Yu Fang Yi Xue Za Zhi. 2015 Nov;49(11):988-92.
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.
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.
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; χ(2) = 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; χ(2) = 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).
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.
调查2014年北京地区儿科患者分离出的A组链球菌（GAS）的超抗原基因谱，探讨超抗原基因谱与emm型以及GAS感染与疾病之间的关系。
2014年5月至7月，从北京36家医院临床诊断为猩红热和咽炎的儿科患者中分离出259株GAS菌株。采用实时荧光定量PCR检测菌株的超抗原基因（speA、speB、speC、speF、speG、speH、speI、speJ、speK、speL、speM、smeZ、ssa）。对GAS菌株M蛋白N基因片段进行PCR扩增；测序比对后分析产物以确定emm型GAS类型。比较亚组间GAS分离株超抗原基因和emm型分布的差异。
在259株GAS菌株中，13种超抗原的检出率如下：speA为48.6%（126株），speB为99.2%（257株），speC为99.2%（257株），speF为98.8%（256株），speG为98.5%（255株），speH为43.6%（113株），speI为46.3%（120株），speJ为49.0%（127株），smeZ为99.2%（257株），ssa为98.5%（255株），未发现speK、speL和speM。共观察到11种超抗原基因谱（A - K）。emm1菌株中携带speA和speJ的比例分别为94.2%（113/120）、95.0%（114/120），显著高于emm12菌株（分别为5.6%（7/124）、5.6%（7/124）；χ(2)=191.20，194.80，P<0.001）。emm12菌株中携带speH和speI的比例分别为83.9%（104/124）、88.7%（110/124），显著高于emm1菌株（分别为3.3%（4/120）、4.2%（5/120）；χ(2)=160.30，174.90，P<0.001）。从猩红热和咽炎病例中分离出的GAS菌株的超抗原基因型和emm型无显著差异（P>0.05）。
2014年北京地区儿科患者分离出的GSA菌株中，speB、speC、speF、smeZ、speG、ssa的检出率较高，未在任何GAS菌株中检测到speK、speL和speM。超抗原基因似乎与emm型有关。此外，猩红热和咽炎之间的emm型分布和超抗原基因无差异。
