Study on the superantigen gene profiles of group A Streptococcus isolated from children in Beijing, 2014.

Guilan LU; Daitao Zhang; Jiachen Zhao; Yimeng Liu; Jing Guo; Shuangsheng WU; Li Zhang; Peng Yang; Quanyi Wang; Xiaomin Peng; Email: Xminp@tomcom

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Study on the superantigen gene profiles of group A Streptococcus isolated from children in Beijing, 2014.

Author: Guilan LU ¹ ; Daitao ZHANG ¹ ; Jiachen ZHAO ¹ ; Yimeng LIU ¹ ; Jing GUO ¹ ; Shuangsheng WU ¹ ; Li ZHANG ¹ ; Peng YANG ¹ ; Quanyi WANG ¹ ; Xiaomin PENG ² ; Email: XMINP@TOM.COM.
Author Information

1. Institute of Infectious Disease and Endemic Disease Control, Beijing Centers for Disease Control and Prevention, Beijing 100013, China.
2. Institute of Infectious Disease and Endemic Disease Control, Beijing Centers for Disease Control and Prevention, Beijing 100013, China
Publication Type:Journal Article
MeSH: Antigens, Bacterial; genetics; Beijing; Child; Genotype; Humans; Real-Time Polymerase Chain Reaction; Streptococcal Infections; microbiology; Streptococcus pyogenes; genetics; immunology; Superantigens; genetics
From: Chinese Journal of Preventive Medicine 2015;49(11):988-992
CountryChina
Language:Chinese
Abstract:
OBJECTIVETo 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.
METHODSA 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.
RESULTSAmong 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).
CONCLUSIONThe 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.