摘要
目的描述2011年北京市朝阳区儿童A组溶血性链球菌（GAS）的超抗原分子流行病学特征，分析超抗原基因与emm型别和GAS相关疾病的关系。方法从猩红热、咽炎及扁桃体炎患儿的咽拭子分离培养获得71株GAS，应用PCR法检测这些GAS是否携带8类超抗原基因（speA、spel、$sa、speC、speJ、speG、spell和SMEZ）；PCR扩增emm基因片段并测序，进行emm型别鉴定；分析超抗原基因、emm型别和GAS所致疾病之间的相互关系，应用，检验进行显著性分析。结果71株GAS的超抗原基因检出率从高到低分别为speC（100．0％）、SMEZ（100．0％）、s50（97．2％）、speG（95．8％）、speH（80．3％）、spel（80．3％）、speA（15．5％）和speJ（12．7％）；71株GAS中检出emml2．0型菌株62株、emml．0型7株、emm22．0型1株、emm75．0型1株；spel和渺H基因与speA和speJ基因在emml2．0型与emml．0型菌株中的分布差异有统计学意义（P均〈0．05）；spel和spetf基因在猩红热患儿和咽炎扁桃体炎患儿中的分布差异有统计学意义（P均〈0．05）；未发现emm型别在不同的疾病中的分布有差异。结论北京市朝阳区儿童携带的GAS超抗原基因的检出率与地域有一定关系；不同emm型别的GAS对超抗原基因的携带有一定的选择性，尤其是针对噬菌体携带的超抗原基因；较emm型别，超抗原基因能更好地建立菌株与疾病之间的关系。
Objective To describe the molecular epidemiological characteristics of superantigens of group A Streptococcus （GAS） in Chaoyang district, Beijing,2011,and to analyze the relationship between superantigen genes, emm types and the diseases caused by GAS. Methods The 71 GASs were isolated from the throat swabs of hospita- lized children with scarlet fever, pharyngitis or tonsillitis. The presence of 8 known superantigens were determined in all the strains by PCR, including the speA, spel, ssa, speC, speJ, speG, spell and SMEZ. The emm genes were amplified from each strain and sequenced to determine the emm types using PCR. Based on the ehi-square test, the relationships be- tween superantigen genes, emm types and the diseases caused by GAS were analyzed. Results Eight superantigen genes,including speC,SMEZ,ssa,speG,speH,spel,speA and speJ were found in 100.0% （71/71 cases）, 100.0% （71/ 71 cases） ,97.2% （69/71 cases） ,95.8% （68/71 cases） ,80.3% （57/71 cases） ,80.3% （57/71 cases）, 15.5% （ 11/ 71 cases）and 12.7% （9/71 cases）of all GAS isolates. The most prevalent emm type was emml2.0 （62 isolates） ,fol- lowed by emml.0 （7 isolates）,emm22.0 （1 isolate） and emm75.0 （1 isolate）. The speA and speJ gene were detected primarily in emml. 0 strains（ all P 〈 0.05 ） , while spel and spell genes were in emml2.0 strains（ all P 〈 0.05 ）. The distribution of spell and spel was correlated with the diseases caused by the GAS （ all P 〈 0.05 ）. The distribution of diseases caused by the GAS in the emml2.0 and emml. 0 strains had no significant difference. Conclusions The de- tection rates of the superantigen genes are associated with the region where the GAS are isolated. Conserved superanti- gen profiles for different emnl types, especially the presence or absence of bacteriophage encoded superantigens, support the contention that surface M proteins selectively influence the entry of bacteriophages, including those encoding supe- rantigens. The research ＂also indicates that the presence of superantigen genes is more important for the disease caused by the GAS than emm types.
出处
《中华实用儿科临床杂志》
CAS
CSCD
北大核心
2013年第10期741-744,共4页
Chinese Journal of Applied Clinical Pediatrics
