Mycobacteroides
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Genus: | Mycobacteroides Gupta et al. 2018 |
Mycobacteroides is a genus of Gram-Positive rod-shaped bacteria in the family Mycobacteriaceae from the order Mycobacteriales.[1] The type species of this genus is Mycobacteroides abscessus.
Members of Mycobacteroides were demarcated from the larger genus Mycobacterium in 2018 by Gupta et al. based on evidence from various phylogenetic trees constructed based on conserved genome sequences, comparative genomic analyses and average amino acid identity values.[1] In addition to this genus, the study proposed the division of Mycobacterium into a total of five distinct genera, which was met with some resistance by some of the scientific community. The resistance was based on the grounds that Mycobacterium contains some clinically relevant species and name changes might cause confusion among clinicians and other researchers.[2]
In 2020, Yamada et al. analyzed the fundamental morphological properties of the new genera, including the cell diameter, cell length, cell perimeter, cell circularity and aspect ratio, and determined that there were significant differences between the five genera, thus supporting the new division.[3]
The name Mycobacteroides is derived from the Latin noun Mycobacterium (referring to the bacterial genus) and the Latin suffix "-oides" (translates to resembling). Together the name refers to a genus resembling Mycobacterium.[1]
Biochemical Characteristics and Molecular Signatures[1]
Members of Mycobacteroides are rapidly growing bacteria, forming colonies in less than seven days. Some characteristics of this genus include: negative for nitrate reductase, iron uptake and demonstrating resistance to polymyxin B. The optimal growth temperature is at 30°C, although growth can occur at 35°C. Members also demonstrate a positive result for the 3 day arylsulfatase test. The genome size for Mycobacteroides species are between 4.5-5.6 Mbp, and their G+C content is between 63.9-64.8 mol%. Some species are pathogenic and demonstrated to be involved in infections of the lung, skin and soft tissues. In addition, some species are also resistant to several antimicrobial drugs.
27 conserved signature indels (CSIs) were identified as uniquely present in this genus in proteins such as: DEAD/DEAH box helicase, anion transporter, a membrane protein, nicotinate-nucleotide adenylyltransferase, CoA ester lyase, uracil phosphoribosyltransferase, L-histidine N(alpha)-methyltransferase, DUF58 domain-containing protein, NADH-quinone oxidoreducatase subunit G, ATP-dependent helicase, tRNA (cytidine(34)-2′-O)-methyltransferase, glutamine-fructose-6-phosphate transaminase (isomerizing), error-prone DNA polymerase, and 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphokinase.[1] These molecular signatures were identified through analyses of genome sequences from Mycobacteroides species and provides a reliable molecular method for distinguishing this genus from the other genera within the family Mycobacteriaceae and all other bacteria. Additionally, 24 unique conserved signature proteins (CSPs) were identified for this genus.
References
- 1 2 3 4 5 Gupta, Radhey S.; Lo, Brian; Son, Jeen (2018-02-13). "Phylogenomics and Comparative Genomic Studies Robustly Support Division of the Genus Mycobacterium into an Emended Genus Mycobacterium and Four Novel Genera". Frontiers in Microbiology. 9: 67. doi:10.3389/fmicb.2018.00067. ISSN 1664-302X. PMC 5819568. PMID 29497402.
- ↑ Tortoli, Enrico; Brown-Elliott, Barbara A.; Chalmers, James D.; Cirillo, Daniela M.; Daley, Charles L.; Emler, Stefan; Floto, R. Andres; Garcia, Maria J.; Hoefsloot, Wouter; Koh, Won-Jung; Lange, Christoph (2019-07-01). "Same meat, different gravy: ignore the new names of mycobacteria". European Respiratory Journal. 54 (1). doi:10.1183/13993003.00795-2019. ISSN 0903-1936. PMID 31296783. S2CID 195893005.
- ↑ Yamada, Hiroyuki; Chikamatsu, Kinuyo; Aono, Akio; Murata, Kazuyoshi; Miyazaki, Naoyuki; Kayama, Yoko; Bhatt, Apoorva; Fujiwara, Nagatoshi; Maeda, Shinji; Mitarai, Satoshi (2020). "Fundamental Cell Morphologies Examined With Cryo-TEM of the Species in the Novel Five Genera Robustly Correlate With New Classification in Family Mycobacteriaceae". Frontiers in Microbiology. 11: 562395. doi:10.3389/fmicb.2020.562395. ISSN 1664-302X. PMC 7701246. PMID 33304323.