2种表型试验检测葡萄球菌诱导型克林霉素耐药的评估及基因分析

摘要

目的：评价MicroScan革兰阳性复合板（简称PC33复合板）和D试验（红霉素、克林霉素双纸片法）检测葡萄球菌诱导型克林霉素耐药的性能及耐药基因分析。方法检测115株 PC33复合板检测结果为红霉素耐药而克林霉素敏感的葡萄球菌对红霉素／克林霉素复合孔的耐药性，同时用 D 试验检测红霉素对克林霉素的诱导耐药表型，用聚合酶链反应（PCR）检测大环内酯类-林可酰胺类-链阳霉素 B 类复合药物（MLS）的耐药基因。结果PC33复合板耐药检出率分别为金黄色葡萄球菌61．3％、凝固酶阴性葡萄球菌47．6％，D 试验耐药检出率分别为金黄色葡萄球菌61．3％、凝固酶阴性葡萄球菌51．2％，2种方法的检测结果差异无统计学意义（P ＞0．5）。以 D 试验为判断标准计算 PC33复合板检测克林霉素诱导耐药的敏感性为95．1％，特异性为100．0％；检出 erm 基因常见的结构型 MLS（cMLS）耐药基因 ermA 和诱导型 MLS（iMLS）耐药基因 ermC。结论PC33复合板与 D 试验检测葡萄球菌诱导型克林霉素耐药的结果有很好的一致性；PC33复合板有较好的临床应用价值。实验室应加强克林霉素诱导耐药的检测，以指导临床合理选用抗菌药物。%Objective To evaluate the drug resistance performance and drug resistance gene on the detection of inducible clindamycin resistance in Staphylococcus by MicroScan Gram-positive composite plate(PC33 composite plate) and D test (erythromycin and clindamycin double-disk diffusion method ). Methods The drug resistance of erythromycin/clindamycin composite well of the 1 1 5 isolates which were resistant to erythromycin and sensitive to clindamycin by MicroScan automatic identification was determined.Meanwhile,the inducible resistant phenotype of erythromycin to clindamycin was analyzed by D test,and the resistant gene to macrolide-lincosamide-streptogramin B (MLS)was detected by polymerase chain reaction(PCR).Results The detection rates of PC33 composite plate were 61 .3% for Staphylococcus aureus and 47.6% for coagulase-negative Staphylococcus.The detection rates of D test were 61 .3% for Staphylococcus aureus and 51 .2% for coagulase-negative Staphylococcus.The difference between the 2 methods had no statistical significance(P >0.5).Using D test as a standard to evaluate PC33 composite plate resistant to inducible clidamycin resistance,the sensitivity was 95.1 %,and the specificity was 1 00.0%.The predominant gene for constitutive MLB(cMLS)resistance to clindamycin was ermA.The predominant gene for inducible MLS (iMLS) resistance to clindamycin was ermC.Conclusions The detection results of inducible clindamycin resistance in Staphylococcus by MicroScan Gram-positive composite plate show a coincidence with D test.PC33 composite plate has good clinical significance.The detection of inducible clindamycin resistance should be paid attention in laboratories in order to guide physicians to select antimicrobial agents correctly.