評估BluePointTM MycoID及MALDI-TOF MS在分枝桿菌生長指示管系統進行非結核分枝桿菌鑑定

Evaluation of BluePointTM MycoID and MALDI-TOF MS for Identification of Nontuberculous Mycobacteria from the Flagged Mycobacterium Growth Indicator Tube system

本研究評估BluePointTM MycoID及MALDI-TOF MS（Bruker Biotyper）在陽性Mycobacterium Growth Indicator Tube（MGIT）（BACTEC, MGIT 960 system, Becton-Dickinson, Sparks）系統中菌種鑑定情況，並以16S–23S rDNA ITS定序確認不相符結果，藉以探討最合適的快速非結核分枝桿菌鑑定方法。本次收集的91支陽性MGIT中，BluePointTM MycoID和M ALDI-TOF MS（Bruker Biotyper）準確度分別為97.8%及91.2%。其中11%的MGIT檢體BluePointTM MycoID僅能鑑定到Mycobacterium spp，可知BluePointTM MycoID適合快速提供臨床菌種名稱，但有11%的檢體因菌量不足或菌種資料庫有限，僅能鑑定為Mycobacterium spp。MALDI-TOF MS雖能鑑定較多分枝桿菌菌種，但需等待菌落生成及專業人員經驗累積，因此時效性較差。

BluePointTM MycoID and MALDI-TOF MS(MALDI Biotyper)were evaluated to find accurate and rapid identification of nontuberculous mycobacteria from the positively flagged Mycobacterium Growth Indicator Tube(MGIT)system(BACTEC, MGIT 960 system, Becton-Dickinson, Sparks). The discordant results were checked by 16S–23S rDNA ITS sequencing. Among 91 consecutively positive MGIT cultures, the accuracy of BluePointTM MycoID and MALDI-TOF MS(Bruker Biotyper)were 97.8% and 91.2% respectively. BluePointTM MycoID identified 11% of 91 consecutively positive MGIT cultures only as Mycobacterium species. Although it could provide faster identification of single or multiple NTM species/genus directly from the positively flagged MGIT system, BluePointTM MycoID identified 11% of all samples as Mycobacterium species due to the limited NTM targets included. MALDI-TOF MS(MALDI Biotyper)could identify more species t han those from BluePointTM MycoID, it is time-consuming and need professional experience.