MALDI-TOF MS在短期培养后胸腹腔积液中细菌快速鉴定的应用

目的 对临床胸腹腔积液样本进行短期培养,使用基质辅助激光解析电离飞行时间质谱仪(MALDI-TOF MS)进行细菌鉴定,以建立可用于胸腹腔积液的快速细菌检测方法。方法 收集360例细菌感染的胸腹腔积液(胸腔积液163例、腹腔积液197例),所有样本分为三份:一份常规培养并使用微生物鉴定仪检测; 第二份直接离心集菌后用MALDI-TOF MS鉴定; 第三份与营养肉汤混合并短期培养2 h,离心洗涤后用MALDI-TOF MS鉴定。以微生物鉴定仪结果作为金标准,评估MALDI-TOF MS对短期培养后胸腹腔积液中致病菌的鉴定效能。结果 MALDI-TOF MS对短期培养后两种样本的正确检出率分别为94.5%和90.9%,总的未检出率只有7.5%; 单一细菌生长的样本鉴定结果与常规方法符合率达到94.1%; 能从混合细菌生长的样本中准确鉴定优势菌。结论 经过短期培养后的胸腹腔积液样本,MALDI-TOF MS检出率高,结果可靠; 所需时间比常规培养缩短至少12 h,可为临床准确快速提供病原菌报告。

Application of MALDI-TOF MS for Rapid Identification ofBacteria in Hydrothorax and Ascites after Short-term Culturing

Abstract:Objective To construct a rapid identification method of bacteria in clinical pleural and peritoneal effusion by using matrix assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS)combined with short-term culturing.Methods Atotal of 360 samples of bacterial pleural and peritoneal effusion were collected,including 163 pleural effusion and 197 ascites.Each sample was divided into three parts.One was used for routine culturing and identification,the second was directly identified by MALDI-TOF MS after centrifugal washing,the last was short-term-culturled for 2 hours mixed with nutrient broth,then identified by MALDI-TOF MS after centrifugal washing.The identification efficiencyof MALDI-TOF MS combined with short-term culture method for clinical pleural and peritoneal effusion of pathogenic bacteria was evaluated by using microbial identification instrument as a gold standard.Results Thecorrect detected rates of MALDI-TOF MS combined with short-term culture methodwere 94.5% and 90.9% in the two kinds of samples,while the undetected rate was only 7.5%.The coincidence rate between identification results of single bacterial growth samples and the conventional method was 94.1%.The predominant bacteria could be accurately identified from samples grown with mixed bacteria.Conclusion After short-term cultured,MALDI-TOF MS has a high detection rate,and the result was reliable.The time required for this method was shortened by at least 12 hours compared with hydrothorax and ascites routine colturing.It could provide accurate and rapid reports of pathogenic bacteria for the clinical.