上海地区儿童化脓性链球菌的红霉素耐药基因研究

目的 了解上海地区化脓性链球菌对红霉素的耐药情况及耐药基因谱的特点.方法 2004年11月至2006年6月经复旦大学附属儿科医院传染病门诊诊断为猩红热的患儿,其咽拭子培养分离获得100株化脓性链球菌.应用PCR及序列分析法检测红霉素耐药基因mefA、ermA、ermB在该批菌株中的分布规律及其与红霉素耐药性的关系.结果上海地区化脓性链球菌的红霉素耐药率为98%,克林霉素耐药率为95%,两者耐药性的一致率为97%.100株菌株中含ermB基因的化脓性链球菌94株,占所有菌株的94%,对红霉索耐药率为100%;含mefA基因的化脓性链球菌16株,占所有菌株的16%,对红霉素耐药率为100%;100株菌株中未发现ermA基因.5株菌株未发现ermB基因及mefA基因,其中2株对红霉素敏感,3株对红霉素耐药.mefA基因单独阳性的菌株仅占1%.结论上海地区化脓性链球菌对红霉奈普遍具有较高耐药率,且与克林霉素存在较严重的交叉耐药.ermB基因是决定上海地区化脓性链球菌对红霉素耐药的重要基因.

Erythromycin resistant genes in Streptococcus pyogenes of children in Shanghai

Objective To understand the erythromycin resistance rate and the erythromycin resistant gene spectrum in Streptococcus pyogenes strains isolated in Shanghai.Methods The outpatient children who were diagnosed with scarlatinal in the Children's Hospital of Fudan University from November 2004 to June 2006 were enrolled and 100 strains of Streptococcus pyogenes were isolated by pharyngeal swab culture.The distributions ofermA,ermB,mefA genes were determined by polymerase chain reaction(PCR)amplification.The relationship between ermA,ermB,mefA genes and erythromycin resistance were also analyzed.Results The erythromycin and clindamycin resistance rates of Streptococcus pyogenes in Shanghai were 98%and 95%,respectively;the concordance rate of these two drugs was 97%.Among 100 strains of Streptococcus pyogenes,94 strains(94%)contained ermB gene,with 100%of erythromycinresistance rate.Sixteen(16%)contained mefA gene,with 100% of erythromycin resistance rate.ermA was not detected inall the 100 strains.The ermB and mefA genes were not found in 5 strains,among which,2 were susceptible to erythromycin and 3wereresistant to erythromycin.Only 1%of isolates was mefA genesingle positive.Conclusions There is a high erythromycin resistance rate of Streptococcus pyogenes strains isolated inShanghai,and the cross resistance to clindamycin is high.TheermB gene is important erythromycin resistancedeterminants of Streptococcus pyogenes in Shanghai.