MALDI-TOF MS结合短时培养法在阳性血培养病原菌鉴定中的临床应用

目的评估基质辅助激光电离解析-飞行时间质谱(MALDI-TOF MS)结合短时培养法在阳性血培养病原菌鉴定中的应用价值。方法前瞻性收集北京友谊医院2017年3月至10月的162例单一病原菌血培养阳性标本,取3 ml培养液离心后刮取分离胶表层浓集的病原菌,血平板培养1~4 h,直接用菌膜涂靶板,MALDI-TOF MS菌株鉴定,同时与常规培养后再鉴定的传统方法比较菌种鉴定结果的准确性。结果共收集革兰阳性细菌73株,革兰阴性细菌89株。与传统培养法相比,MALDI-TOF MS结合短时培养法的鉴定时间由1~2 d缩短至1~4 h,革兰阳性细菌和革兰阴性细菌的鉴定准确率分别为87.7%和98.9%。结论用MALDI-TOF MS结合短时培养法可以大大缩短阳性血培养病原菌鉴定时间,尤其适用于革兰阴性杆菌所致的血流感染。该方法操作简单,结果可靠,有良好的临床应用价值。

Clinical application of MALDI-TOF MS combined with short-term culture method in the identification of pathogenic organisms positive for blood culture

Objective To evaluate the clinical application of Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry(MALDI-TOF MS)combined with short-term culture method in the identification of pathogenic organisms positive for blood culture.Methods One hundred and sixty-two specimens of single bacterial infection in blood cultures were prospectively collected in Beijing Friendship Hospital from March to October 2017.An aliquot(3 ml)of each culture was transferred into a tube with gel separator and centrifuged,the bacterial membrane was selected on the target plate after incubation for 1-4 hours,and the pathogens were identified by MALDI-TOF MS.The accuracy of this novel method of bacteria identification was compared with the conventional method.Results There were seventy-three Gram-positive and eighty-nine Gram-negative bacteria.Compared with the conventional method,the identification time of the MALDI-TOF MS combined with short-term culture method decreased from 1~2 days to 1~4 hours.The identification rates of Gram-positive bacteria and Gram-negative bacteria were 98.9%and 87.7%respectively.Conclusion MALDI-TOF MS combined with short-term culture method can greatly shorten the identification time of positive blood culture pathogens,especially for Gram-negatives.This easy-to-perform and result reliable method is a practical approach for blood infections.