儿童A族β溶血链球菌的主要毒力特征  

Characteristics of major virulence of Group A β-hemolytic streptococcus isolated from children

作　　者：曾婷[1,2,3,4] 王全意[6] 吴琼 林弘睿 董燕红[1,2,3,4] 刘岚[9] 郑跃杰[10] 王丽娟 杨鹏[6] 袁琳[1,2,3,4] 俞桑洁[1,2,3,4] 姚开虎[1,2,3,4] 杨永弘[1,2,3,4] 沈叙庄[1,2,3,4] 

机构地区：[1]首都医科大学附属北京儿童医院,100045 [2]北京市儿科研究所 [3]儿科学国家重点学科 [4]省部共建儿科重大疾病研究重点实验室 [5]重症医学科 [6]北京市疾病预防控制中心传染病地方病拄制所 [7]解放军第309医院 [8]北京大学第四临床医学院北京积水潭医院小儿内科 [9]重庆医科大学附属儿褒医院检验科 [10]深圳市儿童医院呼吸科

出　　处：《中华实用儿科临床杂志》2014年第16期1235-1239,共5页Chinese Journal of Applied Clinical Pediatrics

摘　　要：目的研究儿童A族β溶血链球菌（GAS）分离株超抗原、链球菌DNA酶（DNase）、纤维结合蛋白（FBP）基因的分布特征，分析其与感染儿童及主要cram流行型的关系。方法收集2008年至2012年3所儿童医院临床分离的GAS72株感染菌株，40株健康携带株。PCR扩增及测序对菌株进行emm分型；PCR检测12种超抗原（speA、speC、speH、speI、speG、speJ、ssa、smeZ、speL、speM、speK和speF）、5种DNase基因（sda、sdn、spdI、spd3和spd4）及磷脂酶A2基因sla和FBP基因（prtFl、prtF2、fba）的携带。结果112株GAS分离株，共7种emm型，包括：emml、emml2、emm22、emm4、emm77、emm86、stG485，以emml2型为主，占68．8％，感染株与非感染株emm型分布一致。112株GAS超抗原基因携带率分别为speA 13．4％，speC 95．5％，speF 85．7％，speG 74．1％，speH 63．4％，speI 63．4％，speJ 14．3％，speK、speL、speM各占0．9％，ssa 74，1％，smeZ 93．8％；DNase基因：sda 66．96％，sdn 12．5％，spdI 94．64％，spd 327．68％，spd 40．89％，没有分离株携带sla；FBP基因：prtFI 69．6％，prtF 279．5％，加030．4％，prtFI和prtF2同时阳性67．9％，三者都不携带的占3．6％。感染儿童分离株speJ、spd3的携带率明显高于健康儿童携带株，而ssa，speF，speG、prtFl、prtF2、同时携带prtFl／prtF2甩基因在健康儿童携带株更常见。在emml2型GAS中，speH、speI、speG、sda、spdl、prtFl、prtF2、prtFl和prtF2同时阳性的携带率高于非emml2型，而speA、speJ、sdn、spd3、fba的携带率则低于非emml2型。结论儿童GAS主要流行型为emml2型，其次为emml、emm22型，与菌株来源无关；感染儿童分离株与健康儿童携带株有不同的毒力基因分布特征；emml2型的流行可能与特定毒力基因的高携带有关。Objective To study the prevalence of superantigens, deoxy ribonuclease （DNase） genes and fi- bronectin-binding protein encoding （FBP） genes of Group A Streptococci（GAS） isolated from children,and to analyze its relationship with clinical infections and predominant emm type. Methods A total of 112 strains of GAS were col- lected from three Children＇s Hospitals during the period from 2008 to 2012, including 72 strains from patients and 40 strains from asymptomatic carriers. Emm , superantigens （ speA , speC , speH, speI , speG , speJ , ssa , smeZ , speL , speM , speK and speF） , DNase genes （ sda, sdn, spdl, spd3 and spd4 ） , phospholipase A2 gene and FBP genes （prtFl ,prtF2 .fba ） were amplified by PCR, and emm was further typed by DNA sequencing. Results A total 7 types were identified,inclu- ding emml,emm12,emm22, emm4, emm77, emm86, and stG485. The most common emm type was emml2, which ac- counted for 68.8% of all isolates in this study. The emm type distribution of the pathogens was accorded with the carrier strains. The prevalence of 12 s uperantigens, including speA , speC , spe F , speG , speH, spel , speJ , speK , speL , speM , ssa , smeZ were 13.4% ,95.5% ,85.7% ,74.1%,63.4%,63.4%,14.3%,0.9%,0.9%,0.9%,74.1% and 93.8% ,respec- tively. The prevalence of 5 DNase genes, including sda, sdn, spdl, spd3, spd4, was 66. 96%, 12. 5%, 94. 64%, 27.68% ,0. 89%, respectively. No sla gene was detected. The prevalence of fibroneetin-binding protein, including prtF1 ,prtF2 ,fba, was 69.6% ,79.5% ,30.4% , respectively. The ean＇iage rate of speJ,spd3 from invasive or noninvasive infections was higher than that from asymptomatic carriers,however,the positive rate of ssa,speF,speG,prtF1 ,prtF2 and prtFl/prtF2 was lower than that of asymptomatic carriers. The prevalence of speH, spel, speG, sda, spdl ,prtF1 ,prtF2, prtF1/prtF2 from the emml2 isolates was higher than that from non-emm12 isolates, whereas speA,speJ,sdn,spd3 and .fba were more common in non-cram12 isolates. Conclusions Emm12 is the pre

关 键 词：A族链球菌 毒力因子 emm分型 

分 类 号：R378[医药卫生—病原生物学]