Contreras Samuel, Rodríguez David, Vera Francisco, Balcells María Elvira, Celis Luis, Legarraga Paulette, Román Juan Carlos, García Patricia
Laboratorio de Microbiología, Servicio de Laboratorios Clínicos, Red de Salud UC-CHRISTUS, Santiago, Chile.
Departamento de Laboratorios Clínicos, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
Rev Chilena Infectol. 2020 Jun;37(3):252-256. doi: 10.4067/s0716-10182020000300252.
Mycobacterial diseases are very important both clinically and epidemiologically. Mycobacterium tuberculosis complex (MTBc) infections confer higher morbidity and mortality rate than non-tuberculous mycobacteria (NTM) infections. Traditional species identification techniques are based on phenotypic characteristics which take a long time by laborious processes and in occasions are no conclusive. Currently, most used techniques are based on molecular methods, which are accurate but are expensive and complex. Matrix Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS) is a simple, cheap and fast identification method based on comparing protein spectra with a reference database.
To assess the performance of MALDI-TOF MS in the identification of MTBc and NTM, compared with molecular methods.
For that purpose, 28 isolates of 9 different species were analyzed through MALDI-TOF MS.
78.5% (22/28) of isolates were correctly identified, 100% (9/9) of rapidly growers NTM, 60% (9/15) of slow growing NTM and 100% (4/4) of MTBc. Every unidentified isolate (6/6) corresponded to M. avium/intracellulare complex.
MALDI-TOF MS is fast, simple and cheaper than molecular methods and also has adequate accuracy.
分枝杆菌病在临床和流行病学方面都非常重要。结核分枝杆菌复合群（MTBc）感染比非结核分枝杆菌（NTM）感染导致更高的发病率和死亡率。传统的菌种鉴定技术基于表型特征，过程繁琐且耗时，有时还无法得出结论。目前，最常用的技术基于分子方法，虽然准确，但昂贵且复杂。基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）是一种基于将蛋白质谱与参考数据库进行比较的简单、廉价且快速的鉴定方法。
与分子方法相比，评估MALDI-TOF MS在鉴定MTBc和NTM方面的性能。
为此，通过MALDI-TOF MS对9个不同菌种的28株分离株进行了分析。
78.5%（22/28）的分离株被正确鉴定，快速生长的NTM为100%（9/9），缓慢生长的NTM为60%（9/15），MTBc为100%（4/4）。每株未鉴定的分离株（6/6）均属于鸟分枝杆菌/胞内分枝杆菌复合群。
MALDI-TOF MS快速、简单，比分子方法更便宜，且具有足够的准确性。
