''Mycobacteroides'' is a genus of

Gram-Positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. The Gram stain is ...

rod-shaped bacteria Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archaea ...

in the family ''Mycobacteriaceae'' from the order

Mycobacteriales The Mycobacteriales are an order of bacteria. The current description is genome-based, per Gupta 2019 emendation. Most members produce mycolic acids. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Standi ...

. Members of ''Mycobacteroides'' were demarcated from the larger genus ''

Mycobacterium ''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis (''Mycobacterium tuberculo ...

'' 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. 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. 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. 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''.

Biochemical characteristics and molecular signatures

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 loath 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 and 5.6 Mbp, and their G+C content is between 63.9 and 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 An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth (bacteriostatic agent). Antimicrobial medicines can be grouped according to the microorganisms they are used to treat. For example, antibiotics are used aga ...

drugs. 27

conserved signature indels Conserved signature inserts and deletions (CSIs) in protein sequences provide an important category of molecular markers for understanding phylogenetic relationships. CSIs, brought about by rare genetic changes, provide useful phylogenetic markers ...

(CSIs) were identified as uniquely present in this genus in proteins such as: DEAD/DEAH box helicase, anion transporter, a

membrane protein Membrane proteins are common proteins that are part of, or interact with, biological membranes. Membrane proteins fall into several broad categories depending on their location. Integral membrane proteins are a permanent part of a cell membrane ...

, 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. These molecular signatures were identified through analyses of genome sequences from ''Mycobacteroides'' species and provides a reliable molecular method for distinguishing this genus from theoretical other genera within the family ''Mycobacteriaceae'' and all other bacteria. Additionally, 24 unique conserved signature proteins (CSPs) were identified for this

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

. Whole-genome sequencing is the best way to distinguish members of this genus from each other.

Phylogeny

The phylogeny of ''Mycobacteroides'' is based on whole-genome analysis.

References

{{Taxonbar, from=Q107335170 Mycobacteriales Bacteria genera