葡萄球菌对大环内酯类抗生素耐药性检测

目的检测临床分离的葡萄球菌(金黄色葡萄球菌和表皮葡萄球菌)对大环内酯类抗生素的耐药性。方法用琼脂稀释法测定328株葡萄球菌(金葡菌185株,表皮葡萄球菌143株)对红霉素、罗红霉素、阿奇霉素、克林霉素的最低抑菌浓度(MIC)值,用D实验检测红霉素对克林霉素的诱导耐药性。结果耐甲氧西林金葡菌对红霉素、罗红霉素、阿奇霉素和克林霉素的耐药率分别为90·7%、96·9%、97·9%和84·5%;甲氧西林敏感金葡菌对红霉素、罗红霉素、阿奇霉素和克林霉素的耐药率分别为79·5%、75%、76·1%和72.7%。耐甲氧西林表皮葡萄球菌对红霉素、罗红霉素、阿奇霉素的耐药率均为100·0%,对克林霉素的耐药率为99·1%;甲氧西林敏感表皮葡萄球菌对红霉素的耐药率为94·1%,对罗红霉素、阿奇霉素、克林霉素的耐药率均为97·1%。19株对红霉素耐药、克林霉素敏感的金黄色葡萄球菌,D试验阳性9株(9/19);2株对红霉素耐药、克林霉素敏感的表皮葡萄球菌,D试验均阴性。结论葡萄球菌对大环内酯类抗菌药物耐药显著,此类药物不宜用于葡萄球菌感染的治疗。

Detection of resistance in Staphylococci to marcolide antibiotics

Objective To survey the bacterial resistance to macrolides in staphylococci isolated from Anhui hospitals.Methods MICs of 4 kinds of macrolides against 328 clinical isolates of Staphylococci were determined by agar dilution method.The inducible resistance of erythromycin to clindamcin was checked by D-test.Results The resistance rates of MRSA to erythromycin,roxithromycin,azithromycin,clindamycin were 90.7%,96.9%,97.9%,84.5%,respectively.The resistance rates of MSSA to erythromycin,roxithromycin,azithromycin and clindamycin were 79.5%,75%,76.1% and 72.7%.The resistance rates of MRSE strains to erythromycin,roxithromycin and azithromycin were 100%,and that to clindamycin was 99.1%.The resistance rate of MSSE to erythromycin was 94.1%,and that to roxithromycin,azithromycin were 97.1%.Among 19 strains of staphylococcus aureus with erythromycin resistant and clindamycin sensitive,D-test positive strains were 9(9/19),which phenotypes were iMLS.Among 2 strains of staphylococcus epidermidis with erythromycin resistant and clindamycin sensitive,D-test were negative,whose phenotypes were MS.Conclusion The resistant rates of staphylococci to macrolides are so high that macrolides should not be used for the treatment of infections caused by these isolates.