臨床檢體中致病菌的鑑定－毛細管電泳／串聯質譜儀的應用

Identification of Pathogens in Clinical Samples-Application of Capillary Electrophoresis-Selective Tandem Mass Spectrometry

林呈穎(Cheng-Ying Lin) ； 何彥鵬(Yen-Peng Ho)

《科儀新知》 168期 (2009/02) Pp. 52-60

https://doi.org/10.29662/IT.200902.0005

摘要

利用質譜分析檢體這種複雜樣品是一個很大的挑戰，因為樣品中可能含有多種細菌或其他干擾物。在本研究中我們成功的利用資料庫，搜尋藉由細菌蛋白質萃取後消化所得到的毛細管電泳串聯質譜圖與病菌所特有的蛋白質比對，鑑定出檢體中所含有的病菌，34個檢體分別是從尿液、痰、膿汁與創傷所獲得，而且已經使用生化方法確定其中皆含有革蘭氏陽性菌和革蘭氏陰性菌。利用選擇性串聯質譜的方法進行鑑定，所需的樣品直接由檢體中培養，沒有事先作純化，結果顯示與生化方法比較，可以高達91%的重複性，且如果扣除2個培養失敗的檢體，重複性可以高達97%。

並列摘要

Analysis of microbial mixtures in complex systems, such as clinical samples, using mass spectrometry can be challenging because the specimens may contain mixtures of several pathogens or both pathogens and nonpathogens. We have successfully applied capillary electrophoresis-selective MS/MS of unique peptide marker ions to the identification of common pathogens in clinical diagnosis. The identified peptides that matched a protein associated with a particular pathogen were selected as marker ions to identify that bacterium in clinical specimens. Thirty-four clinical specimens, obtained from pus, wound, sputum, and urine samples, were analyzed using both biochemical and selective MS/MS methods. The bacteria in these clinical samples were cultivated directly, without prior isolation of a pure colony, before performing the selective MS/MS analyses. The match with respect to the pathogens identified was good between the biochemical and the selective MS/MS methods; the matching rate was 91%. The rate was as high as 97% when not considering two specimens where the bacteria were not grown successfully.