MALDI-TOF MS在人工关节置换术后病原菌快速鉴定中的价值

Identification of MALDI-TOF MS in determining the bacteria from artificial joint replacement infection

目的了解基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)联合HB&L微生物培养系统(简称HB&L系统)在人工关节置换术后病原菌快速鉴定中的价值。方法收集104例人工关节置换术后患者关节液样本,分别接种于血培养瓶及常规培养琼脂平板,将阳性培养物分别进行2种直接MALDI-TOF MS鉴定、常规MALDI-TOF MS鉴定和平板培养鉴定,比较4种方法鉴定结果及鉴定时间。结果直接和常规MALDI-TOF MS均检测到84.8%(84/99)的阳性结果,但平板培养仅检测到60.6%(60/99)的阳性结果。HB&L系统处理后直接MALDI-TOF MS鉴定革兰阳性菌和革兰阴性菌,检出率分别为86.9%和91.9%,高于分离胶富集细菌后直接MALDI-TOF MS(78.3%和83.8%)和平板培养(70.1%和67.6%)。HB&L系统处理后直接MALDI-TOF MS鉴定的阳性结果中,金黄色葡萄球菌、表皮葡萄球菌、大肠埃希菌和肺炎克雷伯菌检出率较高。HB&L系统处理后直接MALDI-TOF MS的鉴定时间为5~14 h,低于常规MALDI-TOF MS(45.2 h)和平板培养(54.3 h)。结论与常规培养比较,HB&L系统处理后直接MALDI-TOF MS鉴定病原菌用时短,且具有一定的准确率,对人工关节置换术后病原菌的快速诊断有一定价值。

Objective To study the role of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS)combined with HB&L system to rapidly determine the bacteria from artificial joint replacement infection.Methods The synovial fluid samples of 104 patients with artificial joint replacement infection were collected and inoculated into blood culture flasks and conventional culture agar plates.Positive blood cultures were directly or routinely identified by MALDI-TOF MS,and the type and time of identification were recorded.Results Both direct and conventional MALDI-TOF MS determined a positive result of 84.8%(84/99),but only 60.6%(60/99)was isolated by plate culture.The determination rates of Gram-positive and Gram-negative bacteria by HB&L direct MALDI-TOF MS were 86.9%and 91.9%,respectively,which were higher than those by gel direct MALDI-TOF MS(78.3%and 83.8%)and plate culture(70.1%and 67.6%).Among the positive results of HB&L direct MALDI-TOF MS group,the determination rates of Staphylococcus aureus,Staphylococcus epidermidis,Escherichia coli and Klebsiella pneumoniae were high.The identification time of HB&L direct MALDI-TOF MS was shortened to 5-14 h,which was different from 45.2 h of conventional MALDI-TOF MS or 54.3 h of conventional culture.Conclusions Compared with conventional culture,HB&L direct MALDI-TOF MS shortens the time for microbial identification and has an accuracy rate,which provides a reference for the rapid diagnosis of pathogens in artificial joint replacement.