【摘要】 目的对A族β溶血性链球菌(beta-haemolytic group A streptococcus isolates,GAS)进行多位点序列分型(multilocus sequence typing,MLST)。方法应用多聚酶链反应(polymerase chain reaction,PCR)对来源于2007年北京和上海两地区分属于不同emm分型及其亚型、且对大环内酯类抗生素高水平耐药的14株致儿童猩红热GAS的7对等位看家基因进行扩增,并将目的基因产物测序,然后将所测得的每对等位看家基因的基因序列提交到MLST网站,获得相应的由7对等位看家基因组成的等位基因谱,最后将等位基因谱再次提交到MLST网站,确定GAS临床分离株MLST序列分型(sequence type,ST)。结果 St5240、emm1.0型及其亚型GAS等位基因图谱为4-3-4-4-4-2-4,属于ST28型;emm4.0型GAS等位基因谱为5-7-8-5-15-2-1,属于ST38型;emm12.0型及其亚型GAS等位基因谱为5-2-2-6-6-2-2,属于ST36型;emm22.0型GAS等位基因谱为9-8-1-1-1-3-4,属于ST46型。结论致2007年北京和上海两地区儿童发生猩红热的14株GAS分属于ST28、ST38、ST36及ST46四个不同的克隆系。更多还原

【Abstract】 Objective To analyze beta-hemolytic group A streptococcus (GAS) isolates using multilocus sequence typing (MLST).Methods In 2007,14 GAS isolates of scarlet fever were collected from children in Shanghai and Beijing.All isolates had high-level macrolide resistance and belonged to different emm types and sub-types.Seven house-keeping genes of these isolates were amplified by PCR and sequenced.These sequences were sent to the MLST website for their isoallele sequences to identify their sequence types.Results St5240,emm1.0,and its subtype isolates had the same allelic profiles (4-3-4-4-4-2-4) which belonged to ST28,the emm4.0 isolate (5-7-8-5-15-2-1) belonged to ST38,the emm12.0 and its subtype isolates (5-2-2-6-6-2-2) belonged to ST36,and the emm22.0 isolate (9-8-1-1-1-3-4) belonged to ST46.Conclusions Fourteen GAS isolates obtained from children with scarlet fever in Shanghai and Beijing were found to belong to different clone of ST28,ST36,ST38,and ST46.更多还原