AUTHOR=Zhu Yelei , Liu Zhengwei , Peng Lina , Liu Bin , Wu Kunyang , Zhang Mingwu , Wang Xiaomeng , Pan Junhang 

TITLE=Evaluation of nucleotide MALDI-TOF-MS for the identification of Mycobacterium species

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=14

YEAR=2024

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2024.1335104

DOI=10.3389/fcimb.2024.1335104

ISSN=2235-2988

ABSTRACT=<sec><title>Background</title><p>The accurate identification of the <italic>Mycobacterium</italic> tuberculosis complex (MTBC) and different nontuberculous mycobacteria (NTM) species is crucial for the timely diagnosis of NTM infections and for reducing poor prognoses. Nucleotide matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been extensively used for microbial identification with high accuracy and throughput. However, its efficacy for <italic>Mycobacterium</italic> species identification has been less studied. The objective of this study was to evaluate the performance of nucleotide MALDI-TOF-MS for <italic>Mycobacterium</italic> species identification.</p></sec><sec><title>Methods</title><p>A total of 933 clinical <italic>Mycobacterium</italic> isolates were preliminarily identified as NTM by the MPB64 test. These isolates were identified by nucleotide MALDI-TOF-MS and Sanger sequencing. The performance of nucleotide MALDI-TOF MS for identifying various <italic>Mycobacterium</italic> species was analyzed based on Sanger sequencing as the gold standard.</p></sec><sec><title>Results</title><p>The total correct detection rate of all 933 clinical <italic>Mycobacterium</italic> isolates using nucleotide MALDI-TOF-MS was 91.64% (855/933), and mixed infections were detected in 18.65% (174/933) of the samples. The correct detection rates for <italic>Mycobacterium intracellulare</italic>, <italic>Mycobacterium abscessus</italic>, <italic>Mycobacterium kansasii</italic>, <italic>Mycobacterium avium</italic>, MTBC, <italic>Mycobacterium gordonae</italic>, and <italic>Mycobacterium massiliense</italic> were 99.32% (585/589), 100% (86/86), 98.46% (64/65), 94.59% (35/37), 100.00% (34/34), 95.65% (22/23), and 100% (19/19), respectively. For the identification of the MTBC, <italic>M. intracellulare</italic>, <italic>M. abscessus</italic>, <italic>M. kansasii</italic>, <italic>M. avium</italic>, <italic>M. gordonae</italic>, and <italic>M. massiliense</italic>, nucleotide MALDI-TOF-MS and Sanger sequencing results were in good agreement (<italic>k</italic> &gt; 0.7).</p></sec><sec><title>Conclusion</title><p>In conclusion, nucleotide MALDI-TOF-MS is a promising approach for identifying MTBC and the most common clinical NTM species.</p></sec>