一种PCR检测耐甲氧西林金黄色葡萄球菌株新方法的建立

Establishment of a new method for detecting methicillin-resistant Staphylococcus aureus by PCR

目的建立一种PCR检测耐甲氧西林金黄色葡萄球菌株新方法。方法收集2016年1月至2018年12月入住本院ICU的重症患者的脓液、分泌物、血液等标本中分离培养病原菌株,共43个样本,且均为初次分离所得。以mecA基因检测呈阳性为"金标准",对样本分别进行实时荧光PCR检测和纸片扩散法检测。结果实时荧光PCR方法检测法准确度高于头孢西丁及苯唑西林纸片扩散法;所有耐甲氧西林葡萄球菌对青霉素和苯唑西林药耐药性最强,对红霉素和克林霉素次之,对万古霉素、利奈唑胺、替加环素、利福平均表现为敏感,对四环素、庆大霉素等具备一定的敏感性。结论新建立的荧光PCR检测法相比头孢西丁纸片扩散法和苯唑西林纸片扩散法不仅准确度高,而且特异性好,能够准确检测出耐甲氧西林金黄色葡萄球菌。

Objective To establish a new PCR method for the detection of methicillin-resistant Staphylococcus aureus strains. Methods Pathogenic bacteria strains were isolated and cultured from pus,secretions,blood and other specimens of severe patients admitted to ICU of our hospital from January 2016 to December,2018. A total of 43 samples were collected. All strains originated from different patients and were obtained from initial isolation. Samples were detected by real-time fluorescence PCR and disk diffusion methods,respectively. Results The accuracy of real-time fluorescence PCR method was higher than that of cefoxitin and oxacillin disk diffusion method. All methicillin-resistant staphylococci are resistant to oxacillin and penicillin and more resistant to erythromycin and clindamycin. They are sensitive to vancomycin,linezolid,tigecycline,rifampicin,tetracycline,gentamicin. Conclusion Compared with cefoxitin and oxacillin disk diffusion methods,the newly established fluorescent PCR method not only has high accuracy,but also has good specificity,and can accurately detect methicillin-resistant Staphylococcus aureus.