金黄色葡萄球菌对红霉素和克林霉素诱导耐药分析

目的探讨金黄色葡萄球菌临床分离株对红霉素和克林霉素的耐药性,检测红霉素对克林霉素诱导耐药的发生率。方法采用美国临床实验室标准化研究所（CLSI）推荐的纸片扩散法,检测耐甲氧西林金黄色葡萄球菌（MRSA）以及金黄色葡萄球菌对红霉素和克林霉素的耐药性,并以双纸片法（即D试验）分析红霉素对克林霉素诱导耐药表型。结果金黄色葡萄球菌中MRSA占77.2%。金黄色葡萄球菌对红霉素及克林霉素同时耐药菌株占62.4%,红霉素耐药而克林霉素敏感菌株占21.5%。红霉素耐药而克林霉素敏感的MRSA和甲氧西林敏感金黄色葡萄球菌（MSSA）中D试验阳性分别为72.0%和57.1%。D试验阳性占红霉素耐药而克林霉素敏感金黄色葡萄球菌的68.8%。结论临床微生物实验室应常规开展D试验,检测金黄色葡萄球菌中红霉素对克林霉素的诱导耐药性,以指导临床医师合理选用大环内酯类、林可酰胺类抗菌药物。

Analysis on inducible resistance of erythromycin and clindamycin in Staphylococcus aureus

Objective To investigate the resistance of Staphylococcus aureus isolates to erythromycin and clindamycin,and detect the frequency of inducible resistance of erythromycin to clindamycin.Methods According to the standards of Clinical and Laboratory Standards Institute（CLSI）,disc diffusion method was used to test the methicillin-resistant Staphylococcus aureus（MRSA） and the resistance of Staphylococcus aureus to erythromycin and clindamycin.The inducible resistance phenotype of erythromycin to clindamycin was analyzed by double disc diffusion method（D test）.Results The rate of MRSA in Staphylococcus aureus was 77.2%.The co-resistance strains to erythromycin and clindamycin in Staphylococcus aureus were 62.4%,and the erythromycin-resistant and clindamycin-susceptible strains were 21.5%.The positive rates of D test were 72.0% and 57.1% in erythromycin-resistant and clindamycin-susceptible MRSA and methicillin-sensitive Staphylococcus aureus（MSSA）.D test positive strains accounted for 68.8% among erythromycin-resistant and clindamycin-susceptible strains.Conclusions The inducible resistance of erythromycin to clindamycin in Staphylococcus aureus should be detected by D test in clinical microbiology laboratory in order to guide physicians to select antimicrobial agents correctly such as macrolides and lincosamides.