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目的 比较不同地区B族链球菌 (GBS)对红霉素耐药性的差异及耐药基因谱特点。方法 用琼脂稀释法 ,测定红霉素、克林霉素对不同地区 (北京 ,广州 ,俄罗斯圣彼得堡 )的 113株GBS的最低抑菌浓度 (MIC) ,同时用PCR和核酸杂交的方法 ,检测红霉素耐药基因mreA、mefA、ermA、ermB、ermC在该批菌株中的出现规律及其与红霉素耐药性的关系。结果 (1)北京、广州两地GBS菌株总耐药率为 4 6 % ,与克林霉素耐药性的一致率为 93.8% ;所有ermA基因均来自北京菌株 ,而广州菌株不含该基因。 (2 )含ermA和 (或 )ermB基因的GBS占所有菌株的 30 .0 9% ,其耐药率高达 97.0 6 % ,在已检测的GBS菌株中未发现ermC基因。 (3)分别有 5 3株和 18株含mreA和mefA的GBS以及 1株含ermA的菌株仍对红霉素敏感。 2株GBS不含上述任何一种基因 ,但仍对红霉素耐药。结论 (1)北京、广州两地GBS对红霉素普遍具有较高的耐药率 ,且与大环内酯 林可霉素 链阳性霉素B类抗生素之间存在较严重的交叉耐药 ,临床使用抗生素时应尽量避免重复选择此类抗生素 ;(2 )ermA和ermB是决定我国北京、广州GBS对红霉素耐药的重要基因 ;(3)GBS的耐药性还有其他分子生物学机制参与。
Objective To compare the differences of resistance to erythromycin and the characteristics of resistant gene spectrum of streptococcus pneumoniae in different areas. Methods The minimum inhibitory concentration (MIC) of 113 GBS strains of erythromycin and clindamycin in different regions (Beijing, Guangzhou and St. Petersburg, Russia) was determined by agar dilution method. The inhibitory concentrations of erythromycin and clindamycin were determined by PCR and nucleic acid hybridization. The occurrence rules of mreA, mefA, ermA, ermB and ermC in this batch of strains and their relationship with erythromycin resistance. Results (1) The total drug resistance rate of GBS strains in Beijing and Guangzhou was 46%, which was 93.8% consistent with clindamycin resistance; all ermA genes were from Beijing strains, but Guangzhou strains did not contain this gene . (2) The GBS containing ermA and / or ermB gene accounted for 30.09% of all strains with a resistance rate of 97.0 6%. No ermC gene was detected in the tested GBS strains. (3) 533 strains and 18 strains of GBS containing mreA and mefA and one strain of ermA were still sensitive to erythromycin. Two strains of GBS do not contain any of the above genes, but are still resistant to erythromycin. Conclusion (1) GBS in Beijing and Guangzhou generally have higher resistance rates to erythromycin, and there is more serious cross-resistance between them and the macrolide lincomycin chain positive antibiotic class B antibiotics. (2) ermA and ermB are the important genes that determine the resistance of GBS to erythromycin in Beijing and Guangzhou, China; (3) The resistance of GBS and other molecular biology Mechanism involved.