临床分离的金黄色葡萄球菌mecA和qacA/B基因检测

Detection of mecA and qacA/B Genes in Clinical Isolates of Staphylococcus aureus

目的了解临床分离的金黄色葡萄球菌对常用抗菌药物的耐药性及mecA基因和qacA/B基因携带现状。方法收集临床分离的111株金黄色葡萄球菌,采用K-B药敏纸片法检测其对抗菌药物的耐药性,用聚合酶链反应检测mecA和qacA/B基因。结果 111株金黄色葡萄球菌对青霉素G、氨苄西林、红霉素和苯唑西林的耐药率较高,分别为97.3%、93.4%、86.5%和82.9%,对万古霉素和替考拉宁均敏感;mecA基因和qacA/B基因的检出率分别为63.9%和13.5%;将部分菌株的mecA和qacA/B基因扩增产物进行测序,并将测序结果登录NCBI进行比对。结论临床分离的金黄色葡萄球菌mecA基因检出率较高且呈多药耐药趋势;大部分MRSA和少部分MSSA中携带消毒剂抵抗基因qacA/B;临床应重视由此类金黄色葡萄球菌所引起的感染的诊断、治疗和医院感染的控制,并合理使用消毒剂。

OBJECTIVE To analyze the antibiotics resistance and detection rates of mecA gene and qacA/B gene in clinically isolated Staphylococcus aureus.METHODS A total of 111 strains of S.aureus isolated from clinical specimens were used in this study.Antimicrobial susceptibility tests were performed by K-B method,and the mecA and qacA/B genes were detected by polymerase chain reaction（PCR）.RESULTS Among 111 strains of S.aureus,the resistance rates to penicillin G,ampicillin,erythromycin and oxacillin were noted to be 97.3%,93.4%,86.5% and 82.9%,respectively.And all strains were susceptive to vancomycin and teicoplanin.The detection rates of mecA gene and qacA/B gene were 63.9% and 13.5%.The PCR products were partially purified and subsequently analyzed by direct sequencing.Multiple sequence alignments were carried out using the web site at the National Center for Biotechnology Information（NCBI）.CONCLUSIONS The detection rate of clinical isolates of S.aureus carrying mecA gene is high,and most of them have the trend of multidrug resistance.Most MRSA strains and a few of MSSA strains carry the disinfectant-resistance gene,qacA/B.Thus,we should pay more attention to the diagnosis,therapy and control of nosocomial infection caused by these kinds of MRSA and use disinfectants properly.