Mycolicibacterium
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| Genus: | Mycolicibacterium Gupta et al. 2018 |
Mycolicibacterium 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 Mycolicibacterium fortuitum.
Members of Mycolicibacterium 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 Mycolicibacterium is derived from the Latin noun acidum mycolicum (translates to mycolic acid) and the Latin noun bacterium (translates to small rod). Together the name refers to a genus of mycolic acid containing rod-shaped bacteria.[1]
Biochemical characteristics and molecular signatures[1]
Mycolicibacterium is a genus of rapidly-growing bacteria, taking less than seven days to form colonies. Members are also non-chromogenic (does not produce pigment), and are positive for the 3 day arylsulfatase activity test, nitrate reductase and iron uptake. Most species are saprophytic and are able to process decaying organic matter for nutrients. While members of this genus are not considered to be pathogenic, some species have been reported to cause infections and diseases. The genome size for Mycolicibacterium is between 3.95-8.0 Mbp and their G+C content is between 65.4-70.3 mol%.
Four conserved signature indels (CSIs) were identified through genomic analyses as uniquely present in this genus in the following proteins: LacI family transcriptional regulator, cyclase, CDP-diacylglycerol–glycerol-3-phosphate 3-phosphatidyltransferase and CDP-diacylglycerol–serine O-phosphatidyltransferase.[1] These CSIs serve as a reliable molecular means for distinguishing members of this Mycolicibacterium from other genera in the family Mycobacteriaceae and all other bacteria. Additionally, 10 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.