北京地区儿童A组链球菌感染临床分离株的emm分型研究

摘要

Objective To reveal the genetic distribution of group A streptococcus progeny(GAS)isolated from children with re-spiratory tract infection in Beijing in 2015.Methods The throat swabs were collected from children with clinical diagnosis of scarlet fever and pharyngeal infection during May to July,2015.16 pediatric outpatient departments or pediatric emergency department of hospitals located in 16 districts of Beijing were enrolled in this study.PCR amplification and gene sequencing were employed.The encoding mature M protein gene(emm)distribution in different condition was compared and analyzed.Results A total of 247 GAS were isolated,including 73(29.6%,73/247)isolates from cases with scarlet fever and 174(70.4%,174/247)isolates from cases with pharyngeal infection.Among all isolates,six genotypes of emm were identified,including emm12(53.4%,132/247),emm1(44. 1%,109/247)and others(emm22,emm75,emm131 and emm241,2.5%,6/247).The significant difference of emm distribution with age was observed in this study:emm1 isolates were dominant in children aged 6-12,whereas emm12 isolates were dominant in chil-dren aged 1-5(P<0.05).While the emm distribution showed no significant difference in groups with different location,gender,and disease pattern(P>0.05).Conclusion Emm1 and emm12 were the circulating genotype of GAS in Beijing children,2015.Moreo-ver,the difference of distribution between emm1 and emm12 was proved in this study.%目的 了解2015年北京地区分离自呼吸道感染患儿的A组链球菌(GAS)emm型别分布情况.方法 采集2015年5月至7月北京市16个区16家医院儿科门、急诊临床猩红热病例和咽部感染病例咽拭子标本分离的GAS菌株.应用PCR扩增联合基因测序技术,测定emm型别,并比较不同特征组间的emm基因型别差异.结果 从各区医院采集的咽拭子标本中分离247株GAS菌株.其中来自猩红热患儿73株(29.6%,73/247),咽部感染患儿174株(70.4%,174/247).共检测到6种emm基因型,emm12占53.4%(132/247),emm1占44.1%(109/247),其他型别(emm22、emm75、emm131、emm241)占2.5%(6/247).emm型别的分布在不同年龄组间存在差异,且差异有统计学意义(P<0.05),emm1在6~12岁年龄组中的构成比较高,emm12在1~5岁组中构成比较高.emm型别在地区、性别、疾病类型间差异无统计学意义(P>0.05).结论 2015年北京地区儿童A组链球菌的emm基因型中,主要的流行型别为emm12和emm1,其分布不同年龄组间存在差异.