Abstract: AbstractObjectiveTo investigate the mechanisms of erythromycinresistant streptococcus pnenoniae and their variable antimicrobial resistance. MethodsClindamycin disks were to screen erythromycinresistant streptococcus pneumoniae mediated by ermB ro mefE genes.Antimicrobial resistance of erythromycinresistant streptococcus pneumoniae mediated by ermB of mefE genes were studied by Etest respectively. ResultsErmB and mefE genes were 70.3%(168/239) and 29.7%(71/239) respectively among 239 strains of erythromycinresistant streptococcus pneumoniae.The rates of resistance to penicillin (MIC50 0.19μg/mL,MIC90 1.5μg/mL),amoxicillin/clavulanic acid (MIC50 0.19μg/mL,MIC90 1.0μg/mL),ceftrixone (MIC50 0.19μg/mL,MIC90 0.75μg/mL),cefuroxime (MIC500.38μg/mL,MIC90 2.0μg/mL),cefaclor (MIC502.0μg/mL,MIC90 32.0μg/mL) of erythromycinresistant streptococcus pneumoniae mediated by ermB were 58.4%,1.2%,20.8%,46.5% and 51.7% respectively,and the resistance rates to penicillin(MIC50 0.5μg/mL,MIC90 1.5μg/mL),amoxicillin/clavulanic acid (MIC50 0.38μg/mL,MIC90 1.0μg/mL),ceftrixone (MIC50 0.38μg/mL,MIC90 0.75μg/mL),cefuroxime (MIC501.0μg/mL,MIC90 3.0μg/mL),cefaclor (MIC506.0μg/mL,MIC90 48.0μg/mL) of erythromycinresistant streptococcus pneumoniae mediated by mefE were 67.6%,0,19.7%,59.2% and 61.9% respectively (including decreased susceptibility). ConclusionErythromycinresistant streptococcus pneumoniae mediated by ermB is predominant in Guangzhou,the level of erythromycin resistance mediated by ermB is usually higher due to mefE.Erythromycinresistant streptococcus pneumoniae mediated by ermB or mefE genes also has βlactam resistance in various level.

Key words: Gene , Erythromycin, Drug resistance

摘要： 目的了解广州地区对红霉素耐药的肺炎链球菌中ermB及mefE基因的分布，比较ermB基因与mefE基因对红霉素耐药的肺炎链球菌的耐药性。 方法2001—2004于广州市儿童医院用克林霉素纸片法检测239株对红霉素耐药的肺炎链球菌，并用浓度梯度法检测其耐药性。 结果239株对红霉素耐药的肺炎链球菌中，ermB、mefE基因介导的耐药率分别为70.3%(168/239)和29.7%(71/239)。168株ermB基因介导对红霉素耐药的肺炎链球菌，对青霉素(MIC50 0.19μg/mL、MIC90 1.5μg/mL)、阿莫西林/克拉维酸(MIC50 0.19μg/mL、MIC90 1.0μg/mL)、头孢曲松(MIC50 0.19μg/mL、MIC90 0.75μg/mL)、头孢呋辛(MIC50 0.38μg/mL、MIC90 2.0μg/mL)、头孢克洛(MIC50 2.0μg/mL、MIC90 32.0μg/mL)的不敏感率分别为58.4%、1.2%、20.8%、46.5%和51.7%。71株mefE基因介导对红霉素耐药的肺炎链球菌，对青霉素(MIC50 0.5μg/mL、MIC90 1.5μg/mL)、阿莫西林/克拉维酸(MIC50 0.38μg/mL、MIC90 1.0μg/mL)、头孢曲松(MIC50 0.38μg/mL、MIC90 0.75μg/mL)、头孢呋辛(MIC501.0μg/mL、MIC90 3.0μg/mL)、头孢克洛(MIC50 6.0μg/mL、MIC90 48.0μg/mL)的不敏感率分别为67.6%、0、19.7%、59.2%和61.9%。 结论广州地区对红霉素耐药的肺炎链球菌其耐药机制以ermB基因介导为主；ermB基因介导的红霉素耐药性高于mefE基因介导的耐药性；ermB和mefE基因介导对红霉素耐药的肺炎链球菌对β内酰胺类药物存在不同程度的耐药。

关键词: 链球菌, 肺炎, 红霉素, 抗药性, 基因