Application of MALDI-TOF MS for Rapid Identification of Bacteria in Hydrothorax and Ascites after Short-term Culturing / 现代检验医学杂志

ABSTRACT

Objective To construct a rapid identification method of bacteria in clinical plcural and peritoneal effusion by using matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF MS) combined with short-term culturing.Methods A total of 360 samples of bacterial pleural and peritoneal effusion were collected,including 163 plcural 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 efficiency of 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 The correct detected rates of MALDI-TOF MS combined with short term culture method were 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 con ventional method was 94.1 ％.The predominant bacteria could be accurately identified from samples grown with mixed bac teria.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 ascitcs routine colturing.It could provide accurate and rapid reports of pathogenic bacteria for the clinical.