Open AccessThe influence of culture conditions on the identification of M ycobacterium species by MALDI ‐ TOF MS profiling
Author(s) -
Balážová Tereza,
Makovcová Jitka,
Šedo Ondrej,
Slaný Michal,
Faldyna Martin,
Zdráhal Zbyněk
Publication year - 2014
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/1574-6968.12408
Subject(s) - mycobacterium , matrix assisted laser desorption/ionization , mass spectrometry , microbiology and biotechnology , chromatography , biology , chemistry , mycobacterium smegmatis , bacteria , desorption , genetics , medicine , mycobacterium tuberculosis , pathology , organic chemistry , adsorption , tuberculosis
Matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry ( MALDI ‐ TOF MS ) represents a simple reliable approach for rapid bacterial identification based on specific peptide/protein fingerprints. However, cell‐wall characteristics of mycobacterial species, and their well known stability, complicate MALDI ‐ TOF MS profiling analysis. In this study, we tested two recently published protocols for inactivation and disruption of mycobacteria, and we also examined the influence of different culture conditions (four culture media and five cultivation times) on mass spectral quality and the discriminatory power of the method. We found a significant influence of sample pretreatment method and culture medium on species identification and differentiation for a total of 10 strains belonging to Mycobacterium phlei and Mycobacterium smegmatis . Optimum culture conditions yielding the highest identification success rate against the BioTyper database (Bruker Daltonics) and permitting the possibility of automatic acquisition of mass spectra were found to be distinct for the two mycobacterial species examined. Similarly, individual changes in growth conditions had diverse effects on the two species. For these reasons, thorough control over cultivation conditions should always be employed to maximize the performance and discriminatory power of MALDI ‐ TOF MS profiling, and cultivation conditions must be optimized separately for individual groups of mycobacterial species/strains.