应用显色培养基快速检测血培养中耐甲氧西林金黄色葡萄球菌

目的 评价CHRMOgenic MRSA显色培养基在耐甲氧西林金黄色葡萄球菌(MRSA)所致血流感染的快 速诊断方面应用价值.方法 对2009年1-12月临床常规送检的血培养使用全自动仪器孵育,仪器报警阳性后及时取出血培养瓶,涂片镜检后如发现镜下细菌为革兰阳性球菌、呈葡萄状排列者,转种CHRMOgenic MRSA显色培养基；琼脂稀释法检测耐甲氧西林金黄色葡萄球菌的抗菌药物最低抑菌浓度,双重PCR方法检测菌株nuc、mecA基因；比较CH RMOgenic MRSA显色培养基鉴定结果与实验室常规鉴定及PCR方法鉴定结果.结果 2009年1-12月医院阳性血培养瓶中检出金黄色葡萄球菌72份,其中耐甲氧西林金黄色葡萄球菌48份,凝固酶阴性葡萄球菌491份,血培养分离MRSA耐药率除对万古霉素、替考拉宁、米诺环素较敏感外,对其他多种抗菌药物的耐药率均＞90.0％,CHRMOgenic MRSA显色培养基直接检测阳性血培养瓶中MRSA结果,与常规鉴定及PCR检测结果的符合率高,特异性为98.8％,敏感性为97.9％.结论 阳性血培养涂片镜检与CH RMOgenic MRSA显色培养基相结合,将实验室诊断MRSA血流感染的平均报告时间提前1d,是一种快速有效的简易方法,适于临床实验室的广泛应用.

Rapid detection of methicillin-resistant Staphylococcus aureus in blood culture with CHRMOgenic MRSA medium

OBJECTIVE To evaluate the application of CHRMOgenic MRSA medium in rapid detection of bloodstream infections due to methicillin-resistant Staphylococcus aureus.METHODS Blood culture bottles were incubated in automated system.After the automated system alarmed positive,the specimens were smeared and the ones which showed to be gram-positive cocci in clusters microscopically were subcultured on CHRMOgenic MRSA media from Jan 2009 to Dec 2009;agar dillution method was adopted to measure the MIC of MRSA to antibiotics.PCR method detecting nuc gene and mecA gene was used to verify the MRSA stains.The identification results were compared.RESULTS From Jan 2009 to Dec 2009,72 Staphylococcus aureus(including of 48 MRSA isolates) and 491 coagulase-negative Staphylococcus were isolated from blood culture in laboratory.The resistant rate of MRSA strains isolated from blood was high,with higher than 90.0% to all antibiotics except vancomycin,teicoplanin,and minocycline.The accordance rate of CHRMOgenic MRSA medium screening method with routine identification methods and PCR method was high.The specificity and sensitivity of CHRMOgenic MRSA medium were 98.8% and 97.9%.CONCLUSION Combination smear staining with CHRMOgenic MRSA screening medium,which put forward the reporting time for almost one day,can provide an efficient and rapid method to detect MRSA in positive blood bottle and can be widely applied in clinical laboratories.