導入MALDI-TOF及流程改進以提升厭氧菌鑑定效能

Enhancement of Identification Performance of Anaerobic Bacteria by Implementing MALDI-TOF and Lean Process

厭氧菌可感染身體多種部位，嚴重者會造成菌血症，並且有相當高的致死率。傳統的厭氧菌培養與生化鑑定存在著許多困難與限制，導致鑑定率差及時效長，是臨床微生物實驗室急需改善的一環。本院微生物組於2013年6月導入基質輔助雷射脫附游離飛行時間質譜儀(MALDI-TOF MS)進行厭氧菌鑑定作業，並進一步於2015年1月取消aero-tolerance test操作。藉由此二個步驟，增加鑑定出許多耐氧厭氧菌，如Actinomyces及部分革蘭氏陽性不具芽胞桿菌，厭氧菌培養陽性率因而從15.7%提升至16.9%；菌名鑑定的平均天數亦從7.0天提前至4.4天，於第4天及第6天發出厭氧菌名報告比率分別由0%；40.2%提升至62.1%；88.5%，此外厭氧菌鑑定結果可發出種名之比例由52.9%增加至86.9%，種名的數目由30種提升至大於120種，因此臨床上有意義的厭氧菌種大幅度地被鑑定出來，有效地提升了檢驗品質。此改善成果將可提供臨床醫師更快速診斷及精準的厭氧菌治療方向。 Anaerobes bacteria can infect many body sites and cause sepsis with high mortality rate. Conventional anaerobic culture process and biochemical identification exist unresolvable limitation. Those technical problems lead to poor identification rate and long turnaround time and need efforts for clinical microbiology laboratory to improve. Therefore, in June 2013, our laboratory implemented matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for improvement of anaerobes identification. Furthermore, aero-tolerance test was cancelled for shortening identification process after January 2015. After serially introducing two major process changes, the anaerobes culture rate was increased from 15.7% to 16.9% by added identification of oxygen-tolerant anaerobes such as Actinomyces and Gram positive non spore forming bacillus. The identification turnaround time was also improved from average 7.0 days to 4.4 days. The reporting rate at 4th day and 6th day was increased from 0% and 62.1% to 40.2% and 88.5％ respectively. Besides, the level of identification to species was elevated from 52.9% to 86.9% and the number for species type was enlarged from 30 types to more than 120 ones. That means more clinically significant anaerobes can be identified. In conclusion, by implementing MALDI-TOF and lean process, we successfully improve the identification performance of anaerobic bacteria and it can provide physicians more accurate diagnosis and treatment direction for anaerobic infection.