Evaluation of the performance of MALDI-TOF MS and DNA sequence analysis in the  identification of mycobacteria species

Deniz Ece KAYA,Süheyla SÜRÜCÜOĞLU,Işın AKYAR,Yeşim BEŞLİ,Arzu İLKİ,Meltem AYAŞ,Cengiz ÇAVUŞOĞLU

doi:10.3906/sag-1801-198

Abstract

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry is an alternative way of identifying mycobacteria via the analysis of biomolecules. It is being increasingly used in routine microbiology practice since it permits early, rapid, and cost-effective identification of pathogens of clinical importance. In this study, we aimed to evaluate the efficacy of phenotypic identification of mycobacteria by the MALDI-TOF MS MBT Mycobacteria Library (ML) 4.0 (Bruker, Daltonics) compared to standard sequence analysis. A total of 155 Mycobacterium clinical and external quality control isolates, comprising nontuberculous mycobacteria (NTM) (n = 95) and the Mycobacterium tuberculosis complex (MTC) (n = 60), were included in the study. Identification by MBT ML4.0 was correctly performed in 100% of MTC and in 91% of NTM isolates. All of the MTC isolates were correctly differentiated from NTM isolates. Based on our results, MBT ML4.0 may be used reliably to identify both NTM and MTC.

Highlights

Mycobacterium species constitute an important group of microorganisms that thrive in different natural environments
We aimed to evaluate the efficacy of phenotypic identification of mycobacteria by the MALDI-TOF MS MBT Mycobacteria Library (ML) 4.0 (Bruker, Daltonics) compared to standard sequence analysis
Identification by MBT ML4.0 was correctly performed in 100% of Mycobacterium tuberculosis complex (MTC) and in 91% of nontuberculous mycobacteria (NTM) isolates

Summary

Introduction

Mycobacterium species constitute an important group of microorganisms that thrive in different natural environments. The taxonomy of Mycobacterium consists of more than 177 species, which have been evolving continuously in the recent past, and some species in the genus are human pathogens. The Mycobacterium tuberculosis complex (MTC) is responsible for tuberculosis infection, which is associated with high morbidity and mortality rates [1]. The MTC includes species such as Mycobacterium tuberculosis, Mycobacterium africanum, and Mycobacterium bovis. Other less known species within the MTC are Mycobacterium caprae, Mycobacterium microti, Mycobacterium pinnipedii, Mycobacterium mungi, Mycobacterium suricattae, Mycobacterium orygis, and Mycobacterium canettii [2]. Nontuberculous mycobacteria (NTM) are a group of Mycobacterium species commonly found in the environment, some

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