2003-2008�걱����ͯҽԺŧ�崯����A��β��Ѫ���������������ҩ�����⼰emm�����о�

目的研究北京儿童医院脓疱疮患儿临床分离A组β溶血性链球菌(GAS)及其对抗菌药物的敏感性情况。方法收集北京儿童医院2003—2008年收治的1735例脓疱疮儿童皮损部位分离出的52株GAS菌株,采用琼脂稀释法测定9种抗菌药物的最低抑菌质量浓度(MIC)值;用聚合酶链反应方法对上述菌株进行大环内酯类抗生素耐药基因ermB、ermA和mefA检测以及emm分型情况。结果分离株对四环素及大环内酯类抗生素耐药率均为100%,MIC>256mg/L;对青霉素、头孢拉啶及氧氟沙星的敏感率高达100%。大环内酯类抗生素耐药基因ermB、ermA和mefA和阳性率分别为92.30%、7.70%和0;分离株的emm分型最常见的为emm12.0(53.85%),emm1.0(36.54%)。结论北京儿童医院收治的脓疱疮儿童GAS感染流行菌株对大环内酯类抗生素耐药率很高,主要耐药机制为ermB编码的23SrRNA甲基化酶导致靶位改变,在北京地区青霉素类和头孢菌素类抗生素仍是治疗GAS感染首选药物。

The Characteristics of Streptococcus pyogenes from Chinese children with impetigo between 2003 and 2008

Objective To investigate the characteristics of Streptococcus pyogenes(Group A Streptococcus,GAS) isolat ed from Chinese children with impetigo.Methods The sensitivity of 52 GAS to nine antibiotics(penicillin,cephadine,ofloxacin,chloramphenicol,tetracycline,erythromycin,clarithromycin,clindamycin and azithromycin) was measured as minimal inhibitory concentration(MICs).The macrolide-resistance genes and M protein gene(emm gene) were detected by polymerase chain reaction(PCR).Results Among 52 GAS strains isolated from 1735 patients with impetigo,100%(52/52) were resistant to tetracycline and the macrolide antibiotics erythromycin,clarithromycin,clindamycin and azithro mycin;No isolates were detected with both ermB and ermA,and no isolates were detected with the mefA gene.The most common strains were emm 12.0(28/52,53.85%),and emm 1.0(19/52,36.54%).Rare strains were emm 4.0(1/52,1.92%),emm 8.0(1/52,1.92%),emm 22.0(1/52,1.92%),emm 101(1/521.92%),and emm 114(1/52,1.92%).Conclu sion The most prevalent types were emm1.0 and emm12.0.GAS strains had a high percentage of resistance to macro lide antibiotics and tetracycline.Most expressed the ermB gene and were sensitive to penicillin,cephadine and ofloxacin.