Editing Mycobacterium smegmatis (section)

{{Short description|Species of bacterium}}
{{Speciesbox
| image = Mycobacterium_smegmatis.tif
| taxon = Mycobacterium smegmatis
| authority = (Trevisan 1889)<br>Lehmann &amp; Neumann 1899
}}

'''''Mycobacterium smegmatis''''' is an [[acid-fast]] [[bacterium|bacterial]] species in the [[phylum]] ''[[Actinomycetota]]'' and the [[genus]] ''[[Mycobacterium]]''.  It is 3.0 to 5.0&nbsp;μm long with a [[bacillus (shape)|bacillus]] shape and can be stained by Ziehl–Neelsen method and the auramine-rhodamine fluorescent method. It was first reported in November 1884, who found a [[bacillus]] with the staining appearance of tubercle bacilli in [[syphilis|syphilitic]] [[chancres]].  Subsequent to this, Alvarez and Tavel found organisms similar to that described by Lustgarten also in normal [[genital]] [[secretions]] ([[smegma]]). This organism was later named ''M. smegmatis''.<ref>{{cite journal | vauthors = Gordon RE, Smith MM | title = Rapidly growing, acid fast bacteria. I. Species' descriptions of Mycobacterium phlei Lehmann and Neumann and Mycobacterium smegmatis (Trevisan) Lehmann and Neumann | journal = Journal of Bacteriology | volume = 66 | issue = 1 | pages = 41–8 | date = July 1953 | pmid = 13069464 | pmc = 357089 | doi = 10.1128/jb.66.1.41-48.1953 }}</ref>

Some species of the genus ''Mycobacterium'' have recently been renamed to ''[[Mycolicibacterium]]'', so that ''M. smegmatis'' is now ''Mycolicibacterium smegmatis''.<ref>{{cite journal |vauthors=Gupta RS, Lo B, Son J |title=Phylogenomics and Comparative Genomic Studies Robustly Support Division of the Genus ''Mycobacterium'' into an Emended Genus ''Mycobacterium'' and Four Novel Genera |language=English |journal=Frontiers in Microbiology |volume=9 |pages=67 |date=2018 |pmid=29497402 |pmc=5819568 |doi=10.3389/fmicb.2018.00067 |doi-access=free}}</ref><ref>{{Cite web|last=taxonomy|title=Taxonomy browser (Mycolicibacterium smegmatis) |url= https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=1772&lvl=3&lin=f&keep=1&srchmode=1&unlock |access-date=2021-06-16|website=www.ncbi.nlm.nih.gov}}</ref>

''M. smegmatis'', which was previously considered a nonmotile organism, uses a sliding mechanism that allows it to move around its environment. Henrichsen<ref>{{Cite journal |last=Henrichsen |first=J |date=1972-12-01 |title=Bacterial surface translocation: a survey and a classification |journal=Bacteriological Reviews |language=en |volume=36 |issue=4 |pages=478–503 |doi=10.1128/br.36.4.478-503.1972 |doi-access=free |issn=0005-3678 |pmc=408329 |pmid=4631369}}</ref> defines it as, “a kind of surface translocation produced by the expansive forces in a growing culture in combination with special surface properties of the cells resulting in reduced friction between cell and substrate”. Essentially, the bacteria form a single-layered sheet and are able to move slowly together without the use of any extracellular structures, like flagella or pili. Although it hasn’t been determined exactly how this mechanism works, the surface properties of the unique cell wall of ''M. smegmatis'' have been found to play a role. For example, this sliding ability is correlated with the presence of glycopeptidolipids (GPLs) on the outermost part of the cell wall. GPLs are amphiphilic molecules that could potentially decrease surface interactions or create a conditioning film that allows movement. Although the exact role of GPLs in sliding is not known, without them ''M. smegmatis'' does not have the ability to translocate.<ref>{{Cite journal |last1=Martínez |first1=Asunción |last2=Torello |first2=Sandra |last3=Kolter |first3=Roberto |date=1999-12-01 |title=Sliding Motility in Mycobacteria |journal=Journal of Bacteriology |language=en |volume=181 |issue=23 |pages=7331–7338 |doi=10.1128/JB.181.23.7331-7338.1999 |doi-access=free |issn=0021-9193 |pmc=103697 |pmid=10572138}}</ref>

[[File:M. smegmatis plaque.jpg|thumb|[[Viral plaque|Plaques]] from a [[virus]] isolated from a [[compost]] heap near [[UCLA]]. The [[bacterium]] is ''M. smegmatis'']]