Development of the rapid diagnosis system of the infectious disease using MALDI-TOF-MS

MALDI-TOF-MS作为一种快速鉴定细菌菌落的方法已在医院实验室中流行起来。我们已经开发了一种系统，可以通过应用这种方法快速识别尿液中的致病菌。检测尿液中细菌所需的最小细菌数为100,000个细菌/mL，与革兰氏染色所需的最小细菌数几乎相等。在属水平上，革兰氏阴性杆菌的鉴定一致性达90%以上，革兰氏阳性球菌的鉴定一致性接近65%。整个过程在20分钟内完成。此外，我们试图建立一种方法来检测碳青霉烯酶的生产分离和培养菌落。从产碳青霉烯酶的无性系中提取肽的回收率可达60%以上。然而，由于其他污染蛋白的影响，大多数产生碳青霉烯酶的临床分离株无法检测到。我们将继续研究这个问题。

MALDI-TOF-MS has become prevalent in hospital laboratories as a method to rapidly identify bacterial colonies. We have developed a system that quickly identifies the pathogenic bacteria in urine by applying this method. The minimum bacterial count required for the detection of bacteria in urine was 100,000 bacteria/mL, which was almost equal to that required in Gram staining. At the genus level, the concordance rates of identification were 90% and above in Gram-negative bacillus and nearly 65% in Gram-positive cocci. The whole process was completed within 20 minutes. Furthermore, we tried to develop a method that detected the production of carbapenemase by using isolated and cultured colonies. The recovery of peptides from carbapenemase-producing clones was more than 60%. However, most carbapenemase-producing clinical isolates could not be detected because of the influence of other contaminant proteins. We will continue the study of this issue.