纤维结合蛋白基因在儿科A族β溶血性链球菌的分布及与大环内酯类抗生素耐药的关系  

Prevalence of fibronectin-binding protein in Streptococcus pyogenes and its relationship with macrolide resistance

作　　者：冯利娟[1] 杨永弘[1] 俞桑洁[1] 姚开虎[1] 袁林[1] 沈叙庄[1] 

机构地区：[1]首都医科大学附属北京儿童医院儿科研究所微生物室,北京100045

出　　处：《中国感染与化疗杂志》2010年第1期26-30,共5页Chinese Journal of Infection and Chemotherapy

基　　金：国家863项目资助(2006AA02Z417)

摘　　要：目的研究纤维结合蛋白基因在我国儿科A族β溶血性链球菌(GAS)中的分布及与大环内酯类耐药之间的关系。方法收集3所儿童医院191株病原菌株,48株健康携带株,采用琼脂稀释法测定5种大环内酯类抗生素的MIC值,确定其药物敏感性;PCR扩增及测序对菌株进行emm分型;PCR检测纤维结合蛋白基因prtF1、prtF2和大环内酯类抗生素耐药基因ermB、ermTR和mefA。结果分离株的ermB阳性的有186株,ermTR阳性的有11株,prtF1、prtF2及两者同为阳性的菌株携带率分别为67.36%、66.11%和59.00%,prtF1在病原菌株和健康携带株中没有差别,prtF2在健康分离株携带率高于病原菌株,prtF1、prtF2两者集中在emm12,emm22型菌株中阳性率高,而在emm1、emm4型中很少存在。prtF1和prtF2同时阳性在ermB阳性大环内酯类抗生素耐药菌株中更为常见。结论在我国儿科GAS分离株中,以共同携带prtF1/prtF2基因的emm12型菌株为主,多存在于健康儿童中,这可能是造成我国的GAS感染耐药水平高,而侵袭性不高的原因之一。Objective To study the prevalence of the fibronectin-binding protein encoding genes in Streptococcus pyogenes isolated from Chinese children and examine the relationship between such genes and macrolide resistance.Methods A total of 239 strains of S.pyogenes were collected from 3 children′s hospitals in China,including 191 from patients with invasive or noninvasive infections,and 48 from asymptomatic carriers.The minimum inhibitory concentrations（MICs） of 5 macrolide antibiotics against these isolates were determined by microdilution technique.emm was typed by PCR amplification and DNA sequencing.The fibronectin-binding protein encoding genes prtF1 and prtF2 and macrolide-resistant genes ermB,ermTR and mefA were amplified by PCR to evaluate their association.Results ermB gene was identified in 186 strains of the S.pyogenes.ermTR was positive in 11 S.pyogenes isolates.The prevalence of prtF1,prtF2 and prtF1＋ prtF2 was 67.36%,66.11% and 59.0% respectively.The prevalence of prtF1 gene did not show significant difference between the pathogens and the carrier strains.However,the prevalence of prtF2 gene was higher in the strains from asymptomatic carriers than the strains isolated from pharyngitis and scarlet fever.The prevalence of prtF1＋prtF2 genes was higher in the strains of emm12 or emm22 type,but rarely found in the strains of emm1 or emm4 type.It was more frequently to find both prtF1 and prtF2 genes co-existing in the ermB-positive macrolide-resistant Streptococcus isolates.Conclusions The emm12-type S.pyogenes carrying both prtF1 and prtF2 genes is the most frequently isolated strains in Chinese children.These strains are mostly carried by healthy children.This may be one of the causes contributing to the high level macrolide resistance in the group A β-hemolytic Streptococcus isolates in China.

关 键 词：链球菌 纤维结合蛋白基因 大环内酯类抗生素耐药 

分 类 号：R450[医药卫生—治疗学]