View source for Medicine:Mycoplasma

{{short description|Genus of bacteria}}
{{Split portions|date=November 2023 |portion=anything not having to do with the current ''Mycoplasma'', i.e. everything except the two Phylogeny trees and the infobox|1=Mollicutes|discuss={{TALKPAGENAME}}#Gupta, possible move}}
{{Automatic taxobox
| image = M. haemofelis IP2011.jpg
| image_caption = ''[[Biology:Mycoplasma haemofelis|Mycoplasma haemofelis]]''
| taxon = Mycoplasma
| authority = J.Nowak 1929
| type_species = ''Mycoplasma mycoides''
| type_species_authority = (Borrel et al. 1910) Freundt 1955 (Approved Lists 1980)
| subdivision_ranks = Species
| subdivision =
See text
| synonyms =
* "''[[Biology:Asterococcus|Asterococcus]]''" <small>Borrel et al. 1910 non Scherffel 1908 non Borkhsenius 1960</small>
* "''Asteromyces''" <small>Wroblewski 1931 non Moreau & Moreau ex Hennebert 1962</small>
* "''Borrelomyces''" <small>Turner 1935</small>
* "''Bovimyces''" <small>Sabin 1941</small>
* ''Haemobartonella'' <small>Tyzzer & Weinman 1939</small>
* "''[[Medicine:Pleuropneumonia|Pleuropneumonia]]''" <small>Tulasne & Brisou 1955</small>
}}
{{Infobox medical condition (new)
| name            = Mycoplasmosis
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| field           = [[Medicine:Infectious disease (medical specialty)|Infectious disease]]
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'''''Mycoplasma''''' is a genus of [[Biology:Bacteria|bacteria]] that, like the other members of the class ''[[Biology:Mollicutes|Mollicutes]]'', lack a [[Biology:Cell wall|cell wall]] around their [[Biology:Cell membrane|cell membrane]]s.<ref name=Sherris>{{cite book | editor1-last = Ryan | editor1-first = KJ | editor2-last = Ray | editor2-first = CG | title = Sherris Medical Microbiology | pages=409–12 |edition = 4th | publisher = McGraw Hill | year = 2004 | isbn = 978-0-8385-8529-0}}</ref> [[Biology:Peptidoglycan|Peptidoglycan]] (murein) is absent. This characteristic makes them naturally resistant to antibiotics that target cell wall synthesis (like the [[Chemistry:Beta-lactam antibiotics|beta-lactam antibiotics]]). They can be parasitic or saprotrophic. Several species are [[Biology:Pathogen|pathogen]]ic in humans, including ''[[Biology:Mycoplasma pneumoniae|M. pneumoniae]]'', which is an important cause of [[Medicine:Atypical pneumonia|"walking" pneumonia]] and other respiratory disorders, and ''[[Biology:Mycoplasma genitalium|M. genitalium]]'', which is believed to be involved in pelvic inflammatory diseases. ''Mycoplasma'' species (like the other species of the class ''Mollicutes'') are among the smallest organisms yet discovered,<ref>{{cite book|title=Infectious Diseases of the Female Genital Tract |url=https://archive.org/details/infectiousdiseas00swee_0 |url-access=registration | publisher=Lippincott Williams & Wilkins, 2009|author1=Richard L. Sweet |author2=Ronald S. Gibbs |year=1985 |isbn=978-0-683-08038-4 }}</ref> can survive without oxygen, and come in various shapes. For example, ''M. genitalium'' is flask-shaped (about 300 x 600 nm), while ''M. pneumoniae'' is more elongated (about 100 x 1000 nm), many ''Mycoplasma'' species are coccoid. Hundreds of ''Mycoplasma'' species infect animals.<ref name="LarsenHwang2010">{{cite journal|last1=Larsen|first1=Bryan|last2=Hwang|first2=Joseph|title=Mycoplasma, Ureaplasma, and Adverse Pregnancy Outcomes: A Fresh Look|journal=Infectious Diseases in Obstetrics and Gynecology|volume=2010|year=2010|pages=1–7|issn=1064-7449|doi=10.1155/2010/521921|pmid=20706675|pmc=2913664|doi-access=free}}</ref>

In casual speech, the name ''"mycoplasma"'' (plural ''mycoplasmas'' or ''mycoplasms'') generally refers to all members of the [[Biology:Mollicutes|class Mollicutes]]. In formal scientific classification, the designation ''Mycoplasma'' refers exclusively to the genus, a member of the [[Biology:Mycoplasmataceae|Mycoplasmataceae]], the only family in the [[Biology:Mycoplasmatales|order Mycoplasmatales]] (see "scientific classification").

== Etymology ==
The term "mycoplasma", from the Greek μύκης, ''{{lang|grc-Latn|mykes}}'' (fungus) and πλάσμα, ''{{lang|grc-Latn|plasma}}'' (formed), was first used by Albert Bernhard Frank in 1889 to describe an altered state of plant cell cytoplasm resulting from infiltration by fungus-like microorganisms.<ref>{{cite journal |last1=Frank |first1=B. |title=Ueber der Pilzsymbiose der Leguminosen |journal=Berichte der Deutschen Botanischen Gesellschaft |date=1889 |volume=7 |pages=332–346 |url=https://www.biodiversitylibrary.org/item/112170#page/344/mode/1up |trans-title=On fungal symbioses of legumes |language=German |quote=From p. 335: "Die durch die Infection entstandene veränderte Art des Plasmas in den Rindenzellen will ich, da sie offenbar durch die Vermischmung mit einem pilzartigen Wesen entstanden ist, als Mycoplasma bezeichnen." [''I want to designate as "mycoplasma" the altered type of plasma in the cortex cells which arose by infection, since it'' [i.e., the altered type of plasma] ''obviously arose by mixing with a fungal organism.''] }}</ref><ref name=Krass_1973>{{cite journal | vauthors = Krass CJ, Gardner MW | date = January 1973 | title = Etymology of the Term Mycoplasma | journal = Int. J. Syst. Evol. Microbiol. | volume = 23 | issue = 1 | pages = 62–64 | doi = 10.1099/00207713-23-1-62 | doi-access = free }}</ref> Julian Nowak later proposed the name mycoplasma for certain filamentous microorganisms imagined to have both cellular and acellular stages in their lifecycles, which could explain how they were visible with a microscope, but passed through filters impermeable to other bacteria.<ref>{{cite book | editor1-last= Browning | editor1-first=G.F. | editor2-last=Citti | editor2-first=C. | title = Mollicutes Molecular Biology and Pathogenesis | pages=1–14 |edition = 1st | publisher = Caister Academic Press | year = 2014 | isbn = 978-1-908230-30-0}}</ref> Later, the name for these mycoplasmas was '''pleuropneumonia-like organisms''' (PPLO), broadly referring to organisms similar in [[Biology:Colonial morphology|colonial morphology]] and filterability to the causative agent (a ''Mycoplasma'' species) of [[Biology:Contagious bovine pleuropneumonia|contagious bovine pleuropneumonia]].<ref name=Edward>{{cite journal |vauthors=Edward DG, Freundt EA | title = The classification and nomenclature of organisms of the pleuropneumonia group | journal = J. Gen. Microbiol. | volume = 14 | issue = 1 | pages = 197–207 | date = February 1956 | pmid = 13306904 | doi = 10.1099/00221287-14-1-197 | url = http://mic.sgmjournals.org/cgi/reprint/14/1/197.pdf | doi-access = free }}</ref> At present, all these organisms are classified as Mollicutes, and the term ''Mycoplasma'' solely refers to the genus.{{cn|date=January 2023}}

==Species that infect humans==
Species of ''Mycoplasma'', other than those listed below, have been recovered from humans, but are assumed to have been contracted from a non-human host. The following species use humans as the primary host:{{cn|date=January 2023}}
{{div col|colwidth=12em}}
* ''[[Biology:Mycoplasma amphoriforme|M. amphoriforme]]''
* ''[[Biology:Mycoplasma buccale|M. buccale]]''
* ''[[Biology:Mycoplasma faucium|M. faucium]]''
* ''[[Biology:Mycoplasma fermentans|M. fermentans]]''
* ''[[Biology:Mycoplasma genitalium|M. genitalium]]''
* ''[[Biology:Mycoplasma hominis|M. hominis]]''
* ''[[Biology:Mycoplasma incognitus|M. incognitus]]''
* ''[[Biology:Mycoplasma lipophilum|M. lipophilum]]''
* ''[[Biology:Mycoplasma orale|M. orale]]''
* ''[[Biology:Mycoplasma penetrans|M. penetrans]]''
* ''[[Biology:Mycoplasma pirum|M. pirum]]''
* ''[[Biology:Mycoplasma pneumoniae|M. pneumoniae]]''
* ''[[Biology:Mycoplasma primatum|M. primatum]]''
* ''[[Biology:Mycoplasma salivarium|M. salivarium]]''
* ''[[Biology:Mycoplasma spermatophilum|M. spermatophilum]]''<ref name="WaitesKatz2005">{{cite journal|last1=Waites|first1=K. B.|last2=Katz|first2=B.|last3=Schelonka|first3=R. L.|title=Mycoplasmas and Ureaplasmas as Neonatal Pathogens|journal=Clinical Microbiology Reviews|volume=18|issue=4|year=2005|pages=757–789|issn=0893-8512|doi=10.1128/CMR.18.4.757-789.2005|pmid=16223956|pmc=1265909|citeseerx=10.1.1.336.7047}}</ref>
{{div col end}}

== Pathophysiology ==
''Mycoplasma'' species have been isolated from women with [[Medicine:Bacterial vaginosis|bacterial vaginosis]].<ref name="LarsenHwang2010"/> ''M. genitalium'' is found in women with [[Medicine:Pelvic inflammatory disease|pelvic inflammatory disease]].<ref>{{Cite journal|last1=Wiesenfeld|first1=Harold C.|last2=Manhart|first2=Lisa E.|date=2017-07-15|title=Mycoplasma genitalium in Women: Current Knowledge and Research Priorities for This Recently Emerged Pathogen|journal=The Journal of Infectious Diseases|volume=216|issue=suppl_2|pages=S389–S395|doi=10.1093/infdis/jix198|issn=1537-6613|pmid=28838078|pmc=5853983}}</ref> In addition, infection is associated with increased risk of [[Medicine:Cervicitis|cervicitis]], [[Medicine:Infertility|infertility]], [[Medicine:Preterm birth|preterm birth]] and spontaneous abortion.<ref name="LisRowhani-Rahbar2015">{{cite journal|last1=Lis|first1=R.|last2=Rowhani-Rahbar|first2=A.|last3=Manhart|first3=L. E.|title=Mycoplasma genitalium Infection and Female Reproductive Tract Disease: A Meta-Analysis|journal=Clinical Infectious Diseases|year=2015|issn=1058-4838|doi=10.1093/cid/civ312|volume=61|issue=3|pages=418–426|pmid=25900174|doi-access=free|hdl=1773/26479|hdl-access=free}}</ref> ''Mycoplasma genitalium'' has developed resistance to some antibiotics.<ref>{{Cite journal| url=https://www.who.int/yaws/2013_Yaws_seminar_Lancet.pdf?ua=1&ua=1|
last1= Mitjà| first1=Oriol| last2=Asiedu| first2=Kingsley| last3=Mabey| first3=David| doi=10.1016/S0140-6736(12)62130-8| title=2013 Yaws Seminar|
journal= Lancet| date=13 February 2013|
volume= 381|
issue= 9868|
pages= 763–73| via=World Health Organization| publisher=The Lancet|
pmid= 23415015|
s2cid= 208791874| format=PDF| access-date=28 March 2020}}</ref> ''Mycoplasma'' species are associated with [[Medicine:Infant respiratory distress syndrome|infant respiratory distress syndrome]], [[Medicine:Bronchopulmonary dysplasia|bronchopulmonary dysplasia]], and [[Medicine:Intraventricular hemorrhage|intraventricular hemorrhage]] in preterm infants.<ref name="LarsenHwang2010"/>
<!--==History==
 removed uncited section
The lack of a cell wall conveys some unique properties of mycoplasmas such as sensitivity to osmotic shock and detergents, resistance to penicillin and other beta-lactam antibiotics, and formation of fried-egg shaped colonies. Sections of mycoplasmas reveal that their cells are essentially built of three organelles: the cell membrane, ribosomes, and a circular double-stranded DNA tightly packed molecule. Their mode of replication is no different from that of other prokaryotes dividing by [[Binary fission|binary fission]]. For binary fission to happen, cytoplasmic division must fully synchronize with genome replication and in mycoplasma, cytoplasmic replication lags behind genome replication, which ultimately results in the formation of multinucleated filaments.

From ''in vitro'' cultivation of mycoplasmas, it has been discovered that they are "fastidious", i.e. difficult to cultivate. The reason for these difficulties for species such as ''Mycoplasma genitalium'' and ''Mycoplasma pneumoniae'' is the lack of all the genes involved in amino acid synthesis, making them dependent on exogenous supply of amino acids and other nutrients. This dependence on exogenous supplies of fatty acids and cholesterol serves as an advantage to conduct further studies on these organisms. In order to compensate for these deficiencies mycoplasmas are grown on complex media, usually consisting of beef heart infusion, peptone, yeast extract, and serum with various supplements.

Mycoplasmas' lack of a cell wall makes them good models for membrane studies. Due to this reason the availability of these membranes in pure state have enabled their chemical, enzymatic and antigenic characterization. The membrane is made of 60% to 70% protein with the remaining 20% to 30% being lipids.<ref name = "Razin">{{cite journal |vauthors=Razin S, Hayflick L | title = Highlights of mycoplasma research—An historical perspective | journal = Biologicals | volume = 38 | issue = 2 | pages = 183–90 | year = 2010 | pmid = 20149687 | doi = 10.1016/j.biologicals.2009.11.008 }}</ref>-->

== Characteristics ==
Over 100 species have been included in the genus ''Mycoplasma'', a member of the class ''[[Biology:Mollicutes|Mollicutes]].'' They are [[Biology:Parasite|parasite]]s or commensals of humans, animals, and plants. The genus ''Mycoplasma'' uses [[Biology:Vertebrate|vertebrate]] and [[Biology:Arthropod|arthropod]] hosts.<ref>{{cite journal|url= |title=Infection with Hemotropic Mycoplasma Species in Patients with or without Extensive Arthropod or Animal Contact|volume=51|issue=10|last1=Maggi|first1=Ricardo G.|last2=Compton|first2=Sarah M.|date=1 October 2013|journal=Journal of Clinical Microbiology|pages=3237–3241|doi=10.1128/JCM.01125-13|pmid=23863574|pmc=3811635|last3=Trull|first3=Chelsea L.|last4=Mascarelli|first4=Patricia E.|last5=Mozayeni|first5=B. Robert|last6=Breitschwerdt|first6=Edward B.}}</ref> Dietary nitrogen availability has been shown to alter [[Biology:Codon usage bias|codon bias]] and genome evolution in ''Mycoplasma'' and ''Phytoplasma''.<ref name="pmid27842572">{{Cite journal | doi = 10.1186/s13059-016-1087-9| title = Dietary nitrogen alters codon bias and genome composition in parasitic microorganisms| journal = Genome Biology| volume = 17| issue = 226| pages = 3–15| year = 2016| last1 = Seward| first1 = Emily| last2 = Kelly | first2 = Steve | pmid = 27842572 | pmc=5109750| doi-access = free}}</ref>

''Mycoplasma'' species are among the smallest free-living organisms (about 0.2 - 0.3&nbsp;µm in diameter).<ref>{{cite web |url=https://www.lecturio.com/concepts/mycoplasma/| title=Mycoplasma|website=The Lecturio Medical Concept Library |access-date= 8 July 2021}}</ref><ref name=":0">{{Cite journal |last1=Kandler |first1=Gertraud |last2=Kandler |first2=Otto |date=1954 |others=(Article in English available) |title=Untersuchungen über die Morphologie und die Vermehrung der pleuropneumonie-ähnlichen Organismen und der L-Phase der Bakterien. I. Lichtmikroskopische Untersuchungen |trans-title=Studies on morphology and multiplication of pleuropneumonia-like organisms and on bacterial L-phase, I. Light microscopy (now mycoplasmas and L-form bacteria) |url=https://badw.de/fileadmin/members/K/1501/1954-Kandler_Kandler-PPLO-I-English2015-03-11.pdf |journal=Archiv für Mikrobiologie |language=German |volume=21 |issue=2 |pages=178–201 |doi=10.1007/BF01816378 |pmid=14350641|s2cid=21257985 }}</ref> They have been found in the pleural cavities of cattle suffering from pleuropneumonia. These organisms are often called MLO (mycoplasma-like organisms) or, formerly, PPLO (pleuropneumonia-like organisms).<ref name="Edward" />

===Important characteristics of ''Mycoplasma'' species===

# Cell wall is absent and [[Biology:Cell membrane|plasma membrane]] forms the outer boundary of the cell.
# Due to the absence of cell walls these organisms can change their shape and leads to [[Biology:Pleomorphism (cytology)|pleomorphic]].
# Lack of nucleus and other membrane-bound organelles.
# Genetic material is a single [[Biology:DNA|DNA]] duplex and is naked.
# Ribosomes are [[Biology:Ribosome|70S]] type.
# Possess a replicating disc at one end which assists replication process and also the separation of the genetic materials.
# [[Biology:Heterotrophic nutrition|Heterotrophic nutrition]]. Some live as [[Biology:Saprotrophic nutrition|saprophytes]] but the majority are parasites of plants and animals. The parasitic nature is due to the inability of mycoplasmal bacteria to synthesise the required growth factor.

=== Cell and colony morphology ===
Due to the lack of a rigid cell wall, ''Mycoplasma'' species (like all ''Mollicutes'')  can contort into a broad range of shapes, from round to oblong. They are [[Biology:Pleomorphism (cytology)|pleomorphic]] and therefore cannot be identified as rods, cocci or spirochetes.<ref>{{Cite book|title=Clinical Microbiology made ridiculously simple|last1=Gladwin |first1=Mark|last2=Trattler |first2=William|last3=Mahan |first3=C. Scott|publisher=MedMaster, Inc.|year=2014|isbn=978-1-935660-15-6|location=Miami, Fl|page=156}}</ref>
[[File:Mycoplasma Howe Bovine Mastitis 2022.jpg|thumb|Colony morphology of Mycoplasma on Hayflick agar]]
Colonies show the typical "fried egg" appearance (about 0.5&nbsp;mm in diameter).<ref name=":0" />

=== Reproduction ===
In 1954, using phase-contrast microscopy, continual observations of live cells have shown that ''Mycoplasma'' species ("mycoplasmas", formerly called pleuropneumonia-like organisms, PPLO, now classified as ''Mollicutes'') and [[Biology:L-form bacteria|L-form bacteria]] (previously also called L-phase bacteria) do not proliferate by binary fission, but by a uni- or multi-polar [[Biology:Budding|budding]] mechanism. Microphotograph series of growing microcultures of different strains of PPLOs, L-form bacteria and, as a control, a Micrococcus species (dividing by binary fission) have been presented.<ref name=":0" />  Additionally, electron microscopic studies have been performed.<ref>{{Cite journal |last1=Kandler |first1=Gertraud |last2=Kandler |first2=Otto |last3=Huber |first3=Oskar |date=1954 |others=(Article in English available) |title=Untersuchungen über die Morphologie und die Vermehrung der pleuropneumonie-ähnlichen Organismen und der L-Phase der Bakterien. II. Elektronenmikroskopische Untersuchungen |trans-title=Studies on morphology and multiplication of pleuropneumonia-like organisms and on bacterial L-phase, II. Electron microscopy (now mycoplasmas and L-form bacteria) |url=https://badw.de/fileadmin/members/K/1501/1954-Kandler_Kandler-PPLO-II-English2015-03-11.pdf |journal=Archiv für Mikrobiologie |language=German |volume=21 |issue=2 |pages=202–216 |doi=10.1007/BF01816379 |pmid=14350642|s2cid=45546531 }}</ref>

== Taxonomy ==

=== History of taxonomy ===
Previously, ''Mycoplasma'' species (often commonly called "mycoplasmas", now classified as ''[[Biology:Mollicutes|Mollicutes]]'') were sometimes considered stable [[Biology:L-form bacteria|L-form bacteria]] or even viruses, but phylogenetic analysis has identified them as bacteria that have lost their cell walls in the course of evolution.<ref>{{Cite journal |last1=Woese |first1=Carl R. |last2=Maniloff |first2=J. |last3=Zablen |first3=L.B. |date=1980 |title=Phylogenetic analysis of the mycoplasmas |url=https://www.pnas.org/content/pnas/77/1/494.full.pdf |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=77 |issue=1 |pages=494–498 |doi=10.1073/pnas.77.1.494 |pmid=692864|bibcode=1980PNAS...77..494W |doi-access=free }}</ref>

<!-- posible WP:COPYVIOThe [[Biology:Bacteria|bacteria]] of the genus ''Mycoplasma'' (trivial name: mycoplasmas) and their close relatives are characterized by lack of a [[Biology:Cell wall|cell wall]] which makes them resistant to antibiotics such as penicillin, cephalosporin and vancomysin, the major antigen determinants are their cell membrane glycolipids and proteins. Furthermore, the lack of cell walls (no peptidoglycan layer) is the reason that they are gram-negative. Despite this, the cells often present a certain shape, with a characteristic small size (it is the smallest free-living bacteria), with typically about 10% of the volume of an ''[[Biology:Escherichia coli|Escherichia coli]]'' cell. These cell shapes presumably contribute to the ability of mycoplasmas to thrive in their respective environments. Most are [[Biology:Coccus|pseudococcoidal]], but there are notable exceptions. Species of the ''M. fastidiosum'' cluster are rod-shaped. Species of the ''M. pneumoniae'' cluster, including ''[[Biology:Mycoplasma pneumoniae|M. pneumoniae]]'', possess a polar extension protruding from the pseudococcoidal cell body. This tip structure, designated an attachment organelle or terminal organelle, is essential for adherence to host cells and for movement along solid surfaces (gliding motility) and is implicated in normal cell division. ''M. pneumoniae'' cells are pleomorphic, with an attachment organelle of regular dimensions at one pole and a trailing filament of variable length and uncertain function at the other end, whereas other species in the cluster typically lack the trailing filament. Other species like ''[[Biology:Mycoplasma mobile|M. mobile]]'' and ''M. pulmonis'' have similar structures with similar functions.

Mycoplasmas are unusual among bacteria in that most require sterols for the stability of their cytoplasmic membrane. Sterols are acquired from the environment, usually as cholesterol from the animal host. Mycoplasmas generally possess a relatively small [[Biology:Genome|genome]] of 0. 58-1. 38 megabases, which results in drastically reduced biosynthetic capabilities and explains their dependence on a host. Additionally they use an alternate [[Biology:Genetic code|genetic code]] in which the codon UGA encodes the amino acid [[Chemistry:Tryptophan|tryptophan]] instead of the usual [[Biology:Stop codon|stop codon]]. They have a low [[Biology:GC-content|GC-content]] (23–40 [[Mole (unit)|mol]]).-->
<!--== First isolation ==
 posible WP:COPYVIO In 1898 Nocard and Roux reported the cultivation of the causative agent of CBPP, which was at that time a grave and widespread disease in cattle herds.<ref name="Nocard_Roux_1898">{{cite journal |vauthors=Nocard EIE, Roux E | title = The microbe of pleuropneumonia. 1896 | journal = Rev. Infect. Dis. | volume = 12 | issue = 2 | pages = 354–8 | year = 1990 | pmid = 2184501 | doi = 10.1093/clinids/12.2.354 | quote = translation of ''Le microbe de la péripneumonie. '' Ann Inst Pasteur '''12''', 240–262, 1898 }}</ref><ref name="Hayflick">{{cite journal | author = Hayflick L, Chanock RM | title = Mycoplasma Species of Man | journal = Bacteriol Rev | volume = 29 | issue = 2 | pages = 185–221 | date = June 1965 | pmid = 14304038 | pmc = 441270 | doi = 10.1128/mmbr.29.2.185-221.1965}}</ref> The disease is caused by ''[[Biology:Mycoplasma mycoides|M. mycoides]]'' subsp. mycoides SC (small-colony type), and the work of Nocard and Roux represented the first isolation of a mycoplasma species. Cultivation was, and still is difficult because of the complex growth requirements.

These researchers succeeded by inoculating a semipermeable pouch of sterile medium with pulmonary fluid from an infected animal and depositing this pouch intraperitoneally into a live rabbit. After fifteen to twenty days, the fluid inside of the recovered pouch was opaque, indicating the growth of a microorganism. Opacity of the fluid was not seen in the control. This turbid broth could then be used to inoculate a second and third round and subsequently introduced into a healthy animal, causing disease. However, this did not work if the material was heated, indicating a biological agent at work. Uninoculated media in the pouch, after removal from the rabbit, could be used to grow the organism [[In vitro|in vitro]], demonstrating the possibility of cell-free cultivation and ruling out viral causes, although this was not fully appreciated at the time.<ref name="Nocard_Roux_1898"/>-->
<!--== Small genome ==
 posible WP:COPYVIO
Recent advances in [[Biology:Molecular biology|molecular biology]] and [[Biology:Genomics|genomics]] have brought the genetically simple mycoplasmas, particularly ''M. pneumoniae'' and its close relative ''[[Biology:Mycoplasma genitalium|M. genitalium]]'', to a larger audience. The second published complete bacterial genome sequence was that of ''M. genitalium'', which has one of the smallest genomes of free-living organisms.<ref name="Fraser">{{cite journal |vauthors=Fraser CM, Gocayne JD, White O, Adams MD, Clayton RA, Fleischmann RD, Bult CJ, Kerlavage AR, Sutton G, Kelley JM, Fritchman RD, Weidman JF, Small KV, Sandusky M, Fuhrmann J, Nguyen D, Utterback TR, Saudek DM, Phillips CA, Merrick JM, Tomb JF, Dougherty BA, Bott KF, Hu PC, Lucier TS, Peterson SN, Smith HO, Hutchison CA, Venter JC | title = The minimal gene complement of Mycoplasma genitalium | journal = Science | volume = 270 | issue = 5235 | pages = 397–403 | date = October 1995 | pmid = 7569993 | doi = 10.1126/science.270.5235.397 | bibcode = 1995Sci...270..397F }}</ref> The ''M. pneumoniae'' genome sequence was published soon afterwards and was the first genome sequence determined by [[Biology:Primer walking|primer walking]] of a [[Biology:Cosmid|cosmid]] library instead of the whole-genome shotgun method.<ref name="pmid8948633">{{cite journal |vauthors=Himmelreich R, Hilbert H, Plagens H, Pirkl E, Li BC, Herrmann R | title = Complete sequence analysis of the genome of the bacterium Mycoplasma pneumoniae | journal = Nucleic Acids Res. | volume = 24 | issue = 22 | pages = 4420–49 | date = November 1996 | pmid = 8948633 | pmc = 146264 | doi = 10.1093/nar/24.22.4420 }}</ref> ''Mycoplasma'' genomics and [[Biology:Proteomics|proteomics]] continue in efforts to understand the
so-called [[Mycoplasma laboratorium|minimal cell]],<ref name="isbn0-306-47287-2">{{cite book |vauthors=Hutchison CA, Montague MG | chapter = Mycoplasmas and the minimal genome concept |veditors=Razin S, Herrmann R | title = Molecular biology and pathogenicity of mycoplasmas | publisher = Kluwer Academic/Plenum | location = New York | year = 2002 | isbn = 0-306-47287-2 }}</ref> to catalog the entire protein content of a cell,<ref name="pmid11271496">{{cite journal |vauthors=Regula JT, Ueberle , Boguth G, Görg A, Schnölzer M, Herrmann R, Frank R | title = Towards a two-dimensional proteome map of Mycoplasma pneumoniae | journal = Electrophoresis | volume = 21 | issue = 17 | pages = 3765–80 | date = November 2000 | pmid = 11271496 | doi = 10.1002/1522-2683(200011)21:17<3765::AID-ELPS3765>3.0.CO;2-6 }}</ref> and generally continue to take advantage of the small genome of these organisms to understand broad biological concepts.-->

The medical and agricultural importance of members of the genus ''Mycoplasma'' and related genera have led to the extensive cataloging of many of these organisms by culture, [[Biology:Serology|serology]], and small sub-unit [[Biology:Ribosomal RNA|rRNA]] gene and whole-genome sequencing. A recent focus in the sub-discipline of [[Biology:Molecular phylogenetics|molecular phylogenetics]] has both clarified and confused certain aspects of the organization of the class ''Mollicutes''.<ref>{{cite book |vauthors=((Johansson K-E)), Pettersson B | chapter = Taxonomy of Mollicutes | title=Molecular Biology and Pathogenicity of Mycoplasmas (Razin S, Herrmann R, eds.)| pages=1–30 | publisher = Kluwer Academic/Plenum | location=New York |year = 2002 | isbn = 0-306-47287-2 }}</ref>

Originally, the [[Biology:Bacterial taxonomy#Vernacular names|trivial name]] "mycoplasmas" commonly denoted all members of the class [[Biology:Mollicutes|Mollicutes]]. The name "Mollicutes" is derived from the Latin Mollis (soft) and cutis (skin), and all of these bacteria do lack a cell wall and the genetic capability to synthesize [[Biology:Peptidoglycan|peptidoglycan]].

Taxonomists once classified ''Mycoplasma'' and relatives in the Phylum [[Biology:Firmicutes|Firmicutes]], consisting of low G+C [[Biology:Gram-positive bacteria|Gram-positive bacteria]] such as ''[[Biology:Clostridium|Clostridium]]'', ''[[Biology:Lactobacillus|Lactobacillus]]'', and ''[[Biology:Streptococcus|Streptococcus]]'', but modern polyphasic analyses situate them in the Phylum [[Biology:Tenericutes|Tenericutes]].<ref>{{cite book | author = Brown DR | chapter = Phylum XVI. Tenericutes Murray 1984a, 356VP | title=Bergey's Manual of Systematic Bacteriology, Second Edition, Vol. 4, (Krieg NR, Staley JT, Brown DR, et al., eds.)| pages=567–568 | publisher = Springer | location=New York |year = 2011 | isbn = 978-0-387-95042-6 }}</ref>

=== Historical approach to genera ===
Historically, the description of a bacterium lacking a cell wall was sufficient to classify it to the genus ''Mycoplasma'' and as such it is the oldest and largest genus of the class with about half of the class' species (107 validly described), each usually limited to a specific host and with many hosts harboring more than one species, some pathogenic and some commensal. In later studies, many of these species were found to be phylogenetically distributed among at least three separate orders. A limiting criterion for inclusion within the genus ''Mycoplasma'' was that the organism has a vertebrate host.

By the 1990s, it had become readily apparent that this approach was problematic: the [[Biology:Type species|type species]], ''[[Biology:Mycoplasma mycoides|M. mycoides]]'', along with other significant mycoplasma species like ''M. capricolum'', is evolutionarily more closely related to the genus ''[[Biology:Spiroplasma|Spiroplasma]]'' in the order [[Biology:Entomoplasmatales|Entomoplasmatales]] than to the other members of the genus ''Mycoplasma''. As a result, if the group was to be rearranged to match phylogeny, a number of medically important species (e.g. ''M. pneumoniae'', ''M. genitalium'') would have to be put in a different genus, causing widespread confusion in medical and agricultural communities. The genus was discussed multiple times by the International Committee on Systematic Bacteriology's (ICSB) subcommittee on Mollicutes between 1992 and 2011, to no effect.<ref name=LPSN/>

Regardless of taxonomy, by 2007 it is solidly known that Molicutes can be divided into four nontaxonomic lineages.<ref name="pmid17687503">{{cite journal |vauthors=Oshima K, Nishida H | title = Phylogenetic relationships among mycoplasmas based on the whole genomic information | journal = J. Mol. Evol. | volume = 65 | issue = 3 | pages = 249–58 | date = September 2007 | pmid = 17687503 | doi = 10.1007/s00239-007-9010-3 }}</ref><ref name=Gupta18/>
* An "Acholeplasma" group consisting of Acholeplasmatales. This group is non-problematic, as it contains no species classified in what was then "Mycoplasma".
* A "[[Biology:Spiroplasma|Spiroplasma]]" or ''mycoides'' group containing ''M. mycoides'' and the aforementioned closely-related species in "Spiroplasma" and [[Biology:Entomoplasmatales|Entomoplasmatales]].
* A ''pneumoniae'' group containing ''M. pneumoniae'' and closely-related species (''M. muris'', ''M. fastidiosum'', ''[[Biology:Ureaplasma urealyticum|U. urealyticum]]''), the currently unculturable haemotrophic mollicutes, informally referred to as haemoplasmas (recently transferred from the genera ''Haemobartonella'' and ''Eperythrozoon''), and ''[[Biology:Ureaplasma|Ureaplasma]]''. This medically important group contains ''M. alvi'' (bovine), ''[[Biology:Mycoplasma amphoriforme|M. amphoriforme]]'' (human), ''[[Biology:Mycoplasma gallisepticum|M. gallisepticum]]'' (avian), ''[[Biology:Mycoplasma genitalium|M. genitalium]]'' (human), ''M. imitans'' (avian), ''[[Biology:Mycoplasma pirum|M. pirum]]'' (uncertain/human), ''M. testudinis'' (tortoises), and ''[[Biology:Mycoplasma pneumoniae|M. pneumoniae]]'' (human). Most, if not all, of these species share some otherwise unique characteristics including an attachment organelle, homologs of the ''M. pneumoniae'' cytadherence-accessory proteins, and specialized modifications of the cell division apparatus.
* A ''hominis'' group containing ''M. hominis'', ''[[Biology:Mycoplasma bovis|M. bovis]]'', ''M. pulmonis'', and ''[[Biology:Mycoplasma hominis|M. hominis]]'', among others.

=== Current taxonomy (Gupta) ===
In 2018, Gupta et al. re-circumscribed the genus ''Mycoplasma'' around ''M. mycoides''. A total of 78 species was removed from ''Mycoplasma'', creating five new genera and a number of higher taxonomic levels. Under this new scheme, a new family Mycoplasmoidaceae was created to correspond to the "pneumoniae" group, with ''M. pneumoniae'' and related species transferred to a new genus ''Mycoplasmoides''. Another new family Metamycoplasmataceae was created to correspond to the "hominis" group. Both families belong to a new order Mycoplasmoitales, distinct from the [[Biology:Mycoplasmatales|Mycoplasmatales]] of ''Mycoplasma''.<ref name=Gupta18>{{cite journal| last1=Gupta|first1=R.S.| last2=Sawnani|first2=S.| last3=Adeolu|first3=M.| last4=Alnajar|first4=S.| last5=Oren|first5=A.| title=Phylogenetic framework for the phylum Tenericutes based on genome sequence data: proposal for the creation of a new order Mycoplasmoidales ord. nov., containing two new families Mycoplasmoidaceae fam. nov. and Metamycoplasmataceae fam. nov. harbouring Eperythrozoon, Ureaplasma and five novel genera| journal=Antonie van Leeuwenhoek| volume=111| issue=9| pages=1583–1630| year=2018| doi=10.1007/s10482-018-1047-3|pmid=29556819 |s2cid=254226604 }}</ref> The taxonomy was accepted by the ICSB with validation list 184 in 2018 and became the [[Biology:Correct name|correct name]]. Both List of Prokaryotic names with Standing in Nomenclature (LPSN)<ref name=LPSN>{{cite web| author=A.C. Parte| url=https://lpsn.dsmz.de/genus/Mycoplasma| title=Mycoplasma| access-date=2022-09-09| publisher=List of Prokaryotic names with Standing in Nomenclature (LPSN)| display-authors=et al.}}</ref> and [[Organization:National Center for Biotechnology Information|National Center for Biotechnology Information]] (NCBI) now use the new nomenclature.<ref name=NCBI>{{cite web| author = Sayers| url=https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Undef&id=2093&lvl=3&keep=1&srchmode=1&unlock| title=Mycoplasma| access-date=2022-09-09| publisher=[[Organization:National Center for Biotechnology Information|National Center for Biotechnology Information]] (NCBI) taxonomy database| display-authors=et al.}}</ref>

Gupta's proposed taxonomy, as expected, moved the medically important "pneumoniae" group out of ''Mycoplasma'' into its own genus. As a result, a number of mycoplasmologists petitioned to the ICSB to reject the name in 2019. They argue that although Gupta's phylogenetic methods were likely solid, the proposed name changes are too sweeping to be practically adopted, citing some principles of the Code such as "name stability".<ref>{{Cite journal |last1=Balish |first1=Mitchell |last2=Bertaccini |first2=A. |last3=Blanchard |first3=A. |last4=Brown |first4=D. |last5=Browning |first5=G.|last6=Chalker |first6=V.|last7=Frey |first7=J.|last8=Gasparich |first8=G.|last9=Hoelzle |first9=L.|last10=Knight |first10=T.|last11=Knox |first11=C.|last12=Chih-Horng |first12=K.|last13=Manso-Silván |first13=L.|last14=May |first14=M.|last15=Pollack |first15=J.D.|last16=Ramírez |first16=A.|last17=Spergser |first17=J.|last18=Taylor-Robinson |first18=D.|last19=Volokhov |first19=D.|last20=Zhao |first20=Y.|date= 2019|title=Recommended rejection of the names Malacoplasma gen. nov., Mesomycoplasma gen. nov., Metamycoplasma gen. nov., Metamycoplasmataceae fam. nov., Mycoplasmoidaceae fam. nov., Mycoplasmoidales ord. nov., Mycoplasmoides gen. nov., Mycoplasmopsis gen. nov. [Gupta, Sawnani, Adeolu, Alnajar and Oren 2018] and all proposed species comb. nov. placed therein
 |journal=International Journal of Systematic and Evolutionary Microbiology |volume=69 |issue=11 |pages=3650–3653 |doi= 10.1099/ijsem.0.003632 |pmid=31385780 |doi-access=free |hdl=11585/720151 |hdl-access=free }}</ref> Gupta and Oren wrote a rebuttal in 2020, further detailing the pre-existing taxonomic problems.<ref>{{cite journal |last1=Gupta |first1=Radhey S. |last2=Oren |first2=Aharon |title=Necessity and rationale for the proposed name changes in the classification of Mollicutes species. Reply to: 'Recommended rejection of the names Malacoplasma gen. nov., Mesomycoplasma gen. nov., Metamycoplasma gen. nov., Metamycoplasmataceae fam. nov., Mycoplasmoidaceae fam. nov., Mycoplasmoidales ord. nov., Mycoplasmoides gen. nov., Mycoplasmopsis gen. nov. [Gupta, Sawnani, Adeolu, Alnajar and Oren 2018] and all proposed species comb. nov. placed therein', by M. Balish et al. (Int J Syst Evol Microbiol, 2019;69:3650–3653) |journal=International Journal of Systematic and Evolutionary Microbiology |date=1 February 2020 |volume=70 |issue=2 |pages=1431–1438 |doi=10.1099/ijsem.0.003869|doi-access=free }}</ref><ref name="ipsn_gen">{{cite web |title=Genus: Mycoplasmoides |url=https://lpsn.dsmz.de/genus/mycoplasmoides |website=lpsn.dsmz.de |language=en}}; see also LPSN FAQ on [https://lpsn.dsmz.de/text/faq#why-and-how-does-lpsn-assign-the-status-correct-name correct name]</ref> In 2022, the ICSP's Judicial Opinion 122 ruled in favor of the name changes proposed by Gupta, meaning they remain valid under the [[Biology:International Code of Nomenclature of Prokaryotes|Prokaryotic Code]]<ref name=JO122/> (and for the purpose of the LPSN, they remain the "[[Biology:Correct name|correct name]]s").<ref name="ipsn_gen"/> However, the older names also remain valid; their use remains acceptable under the Code.<ref name=JO122>{{cite journal |last1=Arahal |first1=David R. |last2=Busse |first2=Hans-Jürgen |last3=Bull |first3=Carolee T. |last4=Christensen |first4=Henrik |last5=Chuvochina |first5=Maria |last6=Dedysh |first6=Svetlana N. |last7=Fournier |first7=Pierre-Edouard |last8=Konstantinidis |first8=Konstantinos T. |last9=Parker |first9=Charles T. |last10=Rossello-Mora |first10=Ramon |last11=Ventosa |first11=Antonio |last12=Göker |first12=Markus |title=Judicial Opinions 112–122 |journal=International Journal of Systematic and Evolutionary Microbiology |date=10 August 2022 |volume=72 |issue=8 |doi=10.1099/ijsem.0.005481 |url=https://www.researchgate.net/publication/362626093}}</ref>

Gupta ''et al.'' 2019 performed some uncontroversial sorting of the order Mycoplasmatales.<ref>{{cite journal |last1=Gupta |first1=Radhey S. |last2=Son |first2=Jeen |last3=Oren |first3=Aharon |title=A phylogenomic and molecular markers based taxonomic framework for members of the order Entomoplasmatales: proposal for an emended order Mycoplasmatales containing the family Spiroplasmataceae and emended family Mycoplasmataceae comprising six genera |journal=Antonie van Leeuwenhoek |date=April 2019 |volume=112 |issue=4 |pages=561–588 |doi=10.1007/s10482-018-1188-4}}</ref>

{| class="wikitable"
|-
! colspan=1 | 16S rRNA based LTP_08_2023<ref name=LTP>{{cite web|title=The LTP |url=https://imedea.uib-csic.es/mmg/ltp/#LTP| access-date=20 November 2023}}</ref><ref>{{cite web|title=LTP_all tree in newick format|url=https://imedea.uib-csic.es/mmg/ltp/wp-content/uploads/ltp/LTP_all_08_2023.ntree |access-date=20 November 2023}}</ref><ref>{{cite web|title=LTP_08_2023 Release Notes| url=https://imedea.uib-csic.es/mmg/ltp/wp-content/uploads/ltp/LTP_08_2023_release_notes.pdf |access-date=20 November 2023}}</ref>
! colspan=1 | 120 marker proteins based GTDB 08-RS214<ref name="about">{{cite web |title=GTDB release 08-RS214 |url=https://gtdb.ecogenomic.org/about#4%7C |website=Genome Taxonomy Database|access-date=10 May 2023}}</ref><ref name="tree">{{cite web |title=bac120_r214.sp_label |url=https://data.gtdb.ecogenomic.org/releases/release214/214.0/auxillary_files/bac120_r214.sp_labels.tree |website=Genome Taxonomy Database|access-date=10 May 2023}}</ref><ref name="taxon_history">{{cite web |title=Taxon History |url=https://gtdb.ecogenomic.org/taxon_history/ |website=Genome Taxonomy Database|access-date=10 May 2023}}</ref>
|-
| style="vertical-align:top|
{{Clade | style=font-size:90%;line-height:80%
|label1=''Mycoplasma'' s.s.
|1={{clade
  |1={{clade
    |1=''M. putrefaciens'' <small>Tully et al. 1974</small>
    |2={{clade
      |1=''M. cottewii'' <small>Da Massa et al. 1994</small>
      |2=''M. yeatsii'' <small>Da Massa et al. 1994</small>
       }}
     }}
  |2={{clade
    |1=''M. capri'' <small>(Edward 1953) Hudson, Cottew & Adler 1967 non El Nasri 1966</small>
    |2={{clade
      |1=''[[Biology:Mycoplasma mycoides|M. mycoides]]'' <small>(Borrel et al. 1910) Freundt 1955</small>
      |2={{clade
        |1=''[[Biology:Mycoplasma capricolum|M. capricolum]]'' <small>Tully et al. 1974</small>
        |2={{clade
          |1=''M.  capricolum capripneumoniae'' <small>Leach, Erno & MacOwan 1993</small>
          |2=''M. leachii'' <small>Manso-Silván et al. 2009</small>
           }}
         }}

       }}
     }}
   }}
}}
|
{{Clade | style=font-size:90%;line-height:80%
|label1=''Mycoplasma'' s.s.
|1={{clade
  |1={{clade
    |1=''M. putrefaciens''
    |2={{clade
      |1=''M. cottewii''
      |2=''M. yeatsii''
       }}
     }}
  |2={{clade
    |1=''M. feriruminatoris'' <small>Fischer et al. 2015</small><ref name=Mycoplasma>[https://lpsn.dsmz.de/genus/mycoplasma LPSN lpsn.dsmz.de]</ref>
    |2={{clade
      |1={{clade
        |1=''M. capri''
        |2=''[[Biology:Mycoplasma mycoides|M. mycoides]]''
         }}
      |2={{clade
        |1=''[[Biology:Mycoplasma capricolum|M. capricolum]]''
        |2=''M. leachii''
         }}
       }}
     }}
   }}
}}
|}
Unassigned species:
{{div col|colwidth=20em}}
* "''Ca.'' M. aoti" <small>Barker et al. 2011</small>
* "''M. bradburyae''" <small>Ramírez et al. 2023</small>
* "''Ca.'' M. corallicola" <small>Neulinger et al. 2009</small>
* "''Ca.'' M. coregoni" <small>corrig. Rasmussen et al. 2021</small>
* "''Ca.'' M. didelphidis" <small>corrig. Pontarolo et al. 2021</small>
* "''Ca.'' M. erythrocervae" <small>Watanabe et al. 2010</small>
* "''Ca.'' M. haematocervi" <small>corrig. Watanabe et al. 2010</small>
* "''Ca.'' M. haematodidelphidis" <small>corrig. Messick et al. 2002</small>
* "''Ca.'' M. haematohydrochoeri" <small>corrig. Vieira et al. 2021</small>
* "''Ca.'' M. haematomacacae" <small>corrig. Maggi et al. 2013</small>
* "''Ca.'' M. haematominiopteri" <small>corrig. Millán et al. 2015</small>
* "''M. haematomyotis''" <small>Volokhov et al. 2023</small>
* "''M. haematophyllostomi''" <small>Volokhov et al. 2023</small>
* "''Ca.'' M. haematonasuae" <small>corrig. Collere et al. 2021</small>
* "''Ca.'' M. haematoparvum" <small>Sykes et al. 2005</small>
* "''Ca.'' M. haematosphigguri" <small>corrig. Valente et al. 2021</small>
* "''Ca.'' M. haematotapirus" <small>Mongruel et al. 2022</small>
* "''Ca.'' M. haematoterrestris" <small>Mongruel et al. 2022</small>
* "''Ca.'' M. haematovis" <small>corrig. Hornok et al. 2009</small>
* "''Ca.'' M. haemoalbiventris" <small>Pontarolo et al. 2021</small>
* "''Ca.'' M. haemobovis" <small>Meli et al. 2010</small>
* "''Ca.'' M. haemomeles" <small>Harasawa, Orusa & Giangaspero 2014</small>
* "''Ca.'' [[Biology:Mycoplasma haemomuris|M. haemomuris]]" <small>(Mayer 1921) Neimark et al. 2002</small>
* "''Ca.'' M. haemoparvum" <small>Kenny et al. 2004</small>
* ''M. hafezii'' <small>Ziegler et al. 2019</small>
* "''[[Biology:Mycoplasma incognitus|M. incognitus]]''" <small>Lo et al. 1989</small>
* "''M. insons''" <small>May et al. 2007</small>
* "''Ca.'' M. kahanei" <small>Neimark et al. 2002</small>
* "''Ca.'' M. mahonii" <small>Aroh, Liles & Halanych 2023</small>
* "''M. monodon''" <small>Ghadersohi & Owens 1998</small>
* ''M. phocimorsus'' <small>Skafte-Holm et al. 2023</small>
* "''M. pneumophila''" <small>Lyerova et al. 2008</small>
* "''Ca.'' M. ravipulmonis" <small>Neimark, Mitchelmore & Leach 1998</small>
* "''Ca.'' M. salmoniarum" <small>corrig. Rasmussen et al. 2021</small>
* ''M. seminis'' <small>Fischer et al. 2021</small>
* "''M. sphenisci''" <small>Frasca et al. 2005</small>
* "''M. timone''" <small>Greub & Raoult 2001</small>
* "''Ca.'' M. tructae" <small>Sanchez et al. 2020</small>
* "''Ca.'' M. turicense" <small>corrig. Willi et al. 2006</small>
* "''M. volis''" <small>Dillehay et al. 1995</small>
* "''M. vulturii''" <small>Oaks et al. 2004</small>
{{div col end}}

== Laboratory contaminant ==
''Mycoplasma'' species are often found in research laboratories as contaminants in [[Biology:Cell culture|cell culture]]. Mycoplasmal cell culture contamination occurs due to contamination from individuals or contaminated cell culture medium ingredients.<ref>{{cite journal|author1=Drexler HG |author2=Uphoff CC |title=Mycoplasma contamination of cell cultures: Incidence, sources, effects, detection, elimination, prevention |journal=Cytotechnology |volume=39 |issue=2 |pages=75–90 |date=2002 |doi=10.1023/A:1022913015916 |pmid=19003295 |pmc=3463982}}</ref> ''Mycoplasma'' cells are physically small – less than 1&nbsp; µm, so are difficult to detect with a conventional [[Engineering:Microscope|microscope]].{{citation needed|date=April 2021}}

Mycoplasmae may induce cellular changes, including [[Biology:Chromosome|chromosome]] aberrations, changes in [[Biology:Metabolism|metabolism]] and cell growth. Severe ''Mycoplasma'' infections may destroy a cell line. Detection techniques include DNA probe, enzyme immunoassays, [[Biology:Polymerase chain reaction|PCR]], plating on sensitive [[Biology:Agar|agar]] and staining with a [[Biology:DNA|DNA]] stain including [[Chemistry:DAPI|DAPI]] or [[Biology:Hoechst stain|Hoechst]].<ref>{{cite book |url=https://www.ncbi.nlm.nih.gov/books/NBK7637/|title=Mycoplasmas|last=Razin|first=S |publisher= The University of Texas Medical Branch at Galveston|date=2001 |via=National Center for Biotechnology Information, U.S. National Library of Medicine |pmid= 21413254 |isbn=978-0-9631172-1-2|access-date= 8 July 2021}}</ref>

An estimated 11 to 15% of U.S. laboratory cell cultures are contaminated with mycoplasma.
A Corning study showed that half of U.S. scientists did not test for ''Mycoplasma'' contamination in their cell cultures. The study also stated that, in former Czechoslovakia, 100% of cell cultures that were not routinely tested were contaminated while only 2% of those routinely tested were contaminated (study p.&nbsp;6). Since the U.S. contamination rate was based on a study of companies that routinely checked for ''Mycoplasma'', the actual contamination rate may be higher. European contamination rates are higher and that of other countries are higher still (up to 80% of Japanese cell cultures).<ref name=Corning>{{cite news | author = John Ryan | title = Understanding and Managing Cell Culture Contamination | page = 24 | publisher = Corning Incorporated | year = 2008 | url = http://catalog2.corning.com/Lifesciences/media/pdf/cccontamination.pdf | access-date = 4 August 2010 | archive-url = https://web.archive.org/web/20110708193101/http://catalog2.corning.com/Lifesciences/media/pdf/cccontamination.pdf | archive-date = 8 July 2011 }}</ref>
About 1% of published [[Biology:Gene Expression Omnibus|Gene Expression Omnibus]] data may have been compromised.<ref name="Astarloa: 2009: BT">{{cite journal |vauthors=Aldecoa-Otalora E, Langdon W, Cunningham P, Arno MJ | title = Unexpected presence of mycoplasma probes on human microarrays | journal = BioTechniques | volume = 47 | issue = 6 | pages = 1013–5 | date = December 2009 | pmid = 20047202 | doi = 10.2144/000113271 | doi-access = free }}</ref><ref name="wlangdon">[http://bioinformatics.essex.ac.uk/users/wlangdon/rnanet/scatter.html#1570561_at.pm1,1570561_at.pm3 Link] {{Webarchive|url=https://web.archive.org/web/20120330212013/http://bioinformatics.essex.ac.uk/users/wlangdon/rnanet/scatter.html#1570561_at.pm1,1570561_at.pm3 |date=30 March 2012 }} into RNAnet showing contamination of GEO. Press plot and drag blue crosshairs to expose links to description of experiments on human RNA samples</ref> Several antibiotic-containing formulations of antimycoplasmal reagents have been developed over the years.<ref name="anti-mycoplasma reagents">[http://www.roche-applied-science.com/proddata/gpip/3_5_3_2_5_1.html BM-Cyclin] {{webarchive|url=https://archive.today/20130202160734/http://www.roche-applied-science.com/proddata/gpip/3_5_3_2_5_1.html |date=2 February 2013 }} by Roche, MRA by ICN, [http://www.invivogen.com/plasmocin Plasmocin] by Invivogen and more recently [http://www.de-plasma.com/Technical.html De-Plasma] {{Webarchive|url=https://web.archive.org/web/20130409211326/http://www.de-plasma.com/Technical.html |date=9 April 2013 }} by TOKU-E.</ref>

== Synthetic mycoplasma genome ==

A chemically synthesized genome of a mycoplasmal cell based entirely on synthetic DNA which can self-replicate has been referred to as ''[[Mycoplasma laboratorium]]''.<ref name="pmid20488990">{{cite journal |vauthors=Gibson DG, Glass JI, Lartigue C, Noskov VN, Chuang RY, Algire MA, Benders GA, Montague MG, Ma L, Moodie MM, Merryman C, Vashee S, Krishnakumar R, Assad-Garcia N, Andrews-Pfannkoch C, Denisova EA, Young L, Qi ZQ, Segall-Shapiro TH, Calvey CH, Parmar PP, Hutchison CA, Smith HO, Venter JC | title = Creation of a bacterial cell controlled by a chemically synthesized genome | journal = Science | volume = 329 | issue = 5987 | pages = 52–6 | date = July 2010 | pmid = 20488990 | doi = 10.1126/science.1190719 | bibcode = 2010Sci...329...52G | doi-access = free }}</ref>

== Pathogenicity ==

Several ''Mycoplasma'' species can [[Biology:Pathogen|cause disease]], including ''M. pneumoniae'', which is an important cause of [[Medicine:Atypical pneumonia|atypical pneumonia]] (formerly known as "walking pneumonia"), and ''M. genitalium'', which has been associated with pelvic inflammatory diseases. Mycoplasma infections in humans are associated with skin eruptions in 17% of cases.<ref name="Andrews">{{cite book |author1=James, William D. |author2=Berger, Timothy G. |title=Andrews' Diseases of the Skin: clinical Dermatology |publisher=Saunders Elsevier |year=2006 |isbn=978-0-7216-2921-6 |display-authors=0}}</ref>{{rp|293}}

=== P1 antigen ===

The P1 antigen is the primary [[Biology:Virulence factor|virulence factor]] of mycoplasma, specifically the Pneumoniae group. P1 is a membrane associated protein that allows adhesion to epithelial cells. The P1 receptor is also expressed on erythrocytes which can lead to autoantibody [[Medicine:Agglutination|agglutination]] from mycobacteria infection.<ref>{{cite book | last1 = Parija | first1 = Subhash Chandra | title = Textbook of Microbiology & Immunology | year = 2014 | isbn = 978-81-312-3624-6 | publisher = Elsevier Health Sciences }}</ref>

===Sexually transmitted infections===
''Mycoplasma'' and ''Ureaplasma'' species are not part of the normal vaginal flora. Some Mollicutes species are spread through sexual contact.<ref name=Sternak/> These species have a negative effect on fertility.<ref name="Sternak">{{cite journal|last1=Ljubin-Sternak|first1=Suncanica|last2=Mestrovic|first2=Tomislav|title=Review: Chlamydia trachonmatis and Genital Mycoplasmias: Pathogens with an Impact on Human Reproductive Health|journal=Journal of Pathogens|page= 183167|date=2014|volume=2014|issue=183167|doi=10.1155/2014/183167|pmid=25614838|pmc=4295611|doi-access=free |quote=The term "mycoplasma" is often used to refer to any members of the class Mollicutes (for the purposes of this review as well), irrespective of the fact whether they truly belong to the genus Mycoplasma}}</ref> Mollicutes species colonizing the human genital tract are:<ref name="Sternak"/>
* ''U. urealyticum''
* ''M. hominis''
* ''M. genitalium''
* ''M. penetrans''
* ''M. primatum'' (considered nonpathogenic)
* ''M. spermatophilum'' (considered nonpathogenic)

''[[Biology:Mycoplasma hominis|M. hominis]]'' causes ''[[Medicine:Male infertility|male sterility]]/Genitals inflammation'' in humans.{{cn|date=January 2023}}

====Infant mortality====

Low birth-weight, preterm infants are susceptible to ''Mycoplasma'' and ''Ureaplasma'' infections.<ref name="WaitesKatz2005"/>

=== Links to cancer ===

Several species of ''Mycoplasma'' are frequently detected in different types of [[Medicine:Cancer|cancer]] cells.<ref name="pmid 11819772">{{cite journal |vauthors=Huang S, Li JY, Wu J, Meng L, Shou CC | title = Mycoplasma infections and different human carcinomas | journal = World Journal of Gastroenterology | volume = 7 | issue = 2 | pages = 266–269 | date = April 2001 | pmid = 11819772 | doi=10.3748/wjg.v7.i2.266 | pmc=4723534 | doi-access = free }}</ref><ref name="pmid22076306">{{cite journal | author = Sinkovics JG | title = Molecular biology of oncogenic inflammatory processes. I. Non-oncogenic and oncogenic pathogens, intrinsic inflammatory reactions without pathogens, and microRNA/DNA interactions (Review) | journal = International Journal of Oncology | volume = 40 | issue = 2 | pages = 305–349 | date = February 2012 | pmid = 22076306 | doi = 10.3892/ijo.2011.1248 | doi-access = free }}</ref><ref name="pmid7479753">{{cite journal |vauthors=Tsai S, Wear DJ, Shih JW, Lo SC | title = Mycoplasmas and oncogenesis: Persistent infection and multistage malignant transformation | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 92 | issue = 22 | pages = 10197–10201 | date = October 1995 | pmid = 7479753 | doi = 10.1073/pnas.92.22.10197 | pmc=40763| bibcode = 1995PNAS...9210197T | doi-access = free }}</ref> These species are:
* [[Biology:Mycoplasma fermentans|''M. fermentans'']]<ref name="pmid 11819772"/><ref name="pmid22076306" /><ref name="pmid7479753" /><ref name="pmid 11575494 ">{{cite journal | author = Cimolai N | title = Do mycoplasmas cause human cancer? | journal = Canadian Journal of Microbiology | volume = 47 | issue = 8 | pages = 691–697 | date = August 2001 | pmid = 11575494 | doi = 10.1139/w01-053 }}</ref><ref name="pmid18059017">{{cite journal |vauthors=Jiang S, Zhang S, Langenfeld J, Lo SC, Rogers MB | title = Mycoplasma infection transforms normal lung cells and induces bone morphogenetic protein 2 expression by post-transcriptional mechanisms | journal = [[Biology:Journal of Cellular Biochemistry|Journal of Cellular Biochemistry]] | volume = 104 | issue = 2 | pages = 580–594 | date = May 2008 | pmid = 18059017 | doi = 10.1002/jcb.21647 | s2cid = 23871175 }}</ref><ref name="pmid16674811">{{cite journal |vauthors=Zhang S, Tsai S, Lo SC | title = Alteration of gene expression profiles during mycoplasma-induced malignant cell transformation | journal = BMC Cancer | volume = 6 | page = 116 | date = May 2006 | pmid = 16674811 | doi = 10.1186/1471-2407-6-116 | pmc=1559712 | doi-access = free }}</ref>
* [[Biology:Mycoplasma genitalium|''M. genitalium'']]<ref name="pmid19721714">{{cite journal |vauthors=Namiki K, Goodison S, Porvasnik S, Allan RW, Iczkowski KA, Urbanek C, Reyes L, Sakamoto N, Rosser CJ | title = Persistent exposure to mycoplasma induces malignant transformation of human prostate cells | journal = PLOS ONE | volume = 4 | issue = 9 | pages = e6872 | date = September 2009 | pmid = 19721714 | pmc = 2730529 | doi = 10.1371/journal.pone.0006872 | bibcode = 2009PLoSO...4.6872N | doi-access = free }}</ref>
* [[Biology:Mycoplasma hyorhinis|''M. hyorhinis'']]<ref name="pmid 11819772"/><ref name="pmid19721714"/><ref name="pmid 8910637 ">{{cite journal |vauthors=Chan PJ, Seraj IM, Kalugdan TH, King A | title = Prevalence of mycoplasma conserved DNA in malignant ovarian cancer detected using sensitive PCR–ELISA | journal = Gynecologic Oncology | volume = 63 | issue = 2 | pages = 258–260 | date = November 1996 | pmid = 8910637 | doi = 10.1006/gyno.1996.0316 }}</ref>
* [[Biology:Mycoplasma penetrans|''M. penetrans'']]<ref name="pmid 11819772"/><ref name="pmid22076306" /><ref name="pmid7479753" /><ref name="pmid 11575494 "/><ref name="pmid16674811"/>
* [[Biology:Ureaplasma urealyticum|''U. urealyticum'']]<ref>{{cite journal |vauthors=Xiaolei C, Taot H, Zongli S, Hongying Y |title=The role of ureaplasma urealyticum infection in cervical intraepithelial neoplasia and cervical cancer |journal=European Journal of Gynaecological Oncology |volume=35 |issue=5 |pages=571–5 |year=2014 |pmid=25423707 }}</ref>

The majority of these ''Mycoplasma'' species have shown a strong correlation to [[Biology:Malignant transformation|malignant transformation]] in mammalian cells ''[[In vitro|in vitro]]''.

==== ''Mycoplasma'' infection and host cell transformation ====

The presence of ''Mycoplasma'' was first reported in samples of cancer tissue in the 1960s.<ref name="pmid7479753" /> Since then, several studies tried to find and prove the connection between ''Mycoplasma'' and cancer, as well as how the bacterium might be involved in the formation of cancer.<ref name="pmid22076306" /> Several studies have shown that cells that are chronically infected with the bacteria go through a multistep transformation. The changes caused by chronic mycoplasmal infections occur gradually and are both [[Biology:Morphology|morphological]] and [[Biology:Genetics|genetic]].<ref name="pmid22076306" /> The first visual sign of infection is when the cells gradually shift from their normal form to sickle-shaped. They also become hyperchromatic due to an increase of DNA in the nucleus of the cells. In later stages, the cells lose the need for solid support to grow and proliferate,<ref>{{Cite journal|last1=Lopes|first1=B. R. P.|last2=Ribeiro|first2=A. G.|last3=Silva|first3=T. F.|last4=Barbosa|first4=L. V.|last5=Jesus|first5=T. I.|last6=Matsuda|first6=B. K.|last7=Costa|first7=M. F.|last8=Toledo|first8=K. A.|date=February 2021|title=Diagnosis and treatment of HEp-2 cells contaminated with mycoplasma|journal=Brazilian Journal of Biology|volume=81|issue=1|pages=37–43|doi=10.1590/1519-6984.215721|pmid=32321065|issn=1678-4375|doi-access=free|hdl=11449/205878|hdl-access=free}}</ref> as well as the normal contact-dependent inhibition cells.<ref name="pmid7479753" />

==== Possible intracellular mechanisms of mycoplasmal malignant transformation ====

=====Karyotypic changes related to mycoplasma infections=====

Cells infected with ''Mycoplasma'' for an extended period of time show significant chromosomal abnormalities. These include the addition of chromosomes, the loss of entire chromosomes, partial loss of chromosomes, and [[Biology:Chromosomal translocation|chromosomal translocation]]. All of these genetic abnormalities may contribute to the process of malignant transformation. Chromosomal translocation and extra chromosomes help create abnormally high activity of certain proto-oncogenes, which caused by these genetic abnormalities and include those encoding c-myc, [[Biology:HRAS|HRAS]],<ref name="pmid 11575494 "/> and [[Biology:Vav (protein)|vav]].<ref name="pmid22076306" /> The activity of proto-oncogenes is not the only cellular function that is affected; tumour suppressor genes are affected by the chromosomal changes induced by mycoplasma, as well. Partial or complete loss of chromosomes causes the loss of important genes involved in the regulation of cell proliferation.<ref name="pmid7479753" /> Two genes whose activities are markedly decreased during chronic infections with mycoplasma are the [[Biology:Retinoblastoma protein|Rb]] and the [[Biology:P53|p53]] tumour suppressor genes.<ref name="pmid22076306" /> Another possible mechanism of carcinogenesis is [[Biology:RAC1|RAC1]] activation by a small GTPase-like protein fragment of Mycoplasma.<ref name=" pmid = 24172987 ">{{cite journal |vauthors=Hu X, Yu J, Zhou X, Li Z, Xia Y, Luo Z, Wu Y | title = A small GTPase-like protein fragment of Mycoplasma promotes tumor cell migration and proliferation in vitro via interaction with Rac1 and Stat3. | journal = Mol Med Rep | volume = 9 | issue = 1 | pages = 173–179 | date = Jan 2014 | pmid = 24172987 | url = http://www.spandidos-publications.com/mmr/9/1/173 | doi=10.3892/mmr.2013.1766| doi-access = free }}</ref> A major feature that differentiates mycoplasmas from other carcinogenic pathogens is that the mycoplasmas do not cause the cellular changes by insertion of their own genetic material into the host cell.<ref name="pmid 11575494 "/> The exact mechanism by which the bacterium causes the changes is not yet known.{{cn|date=January 2023}}

=====Partial reversibility of malignant transformations=====

The malignant transformation induced by ''Mycoplasma'' species is also different from that caused by other pathogens in that the process is reversible. The state of reversal is, however, only possible up to a certain point during the infection. The window of time when reversibility is possible varies greatly; it depends primarily on the ''Mycoplasma'' involved. In the case of ''M. fermentans'', the transformation is reversible until around week 11 of infection and starts to become irreversible between weeks 11 and 18.<ref name="pmid7479753" /> If the bacteria are killed using antibiotics<ref name="pmid7479753" /> (i.e. [[Chemistry:Ciprofloxacin|ciprofloxacin]]<ref name="pmid22076306" /> or [[Chemistry:Clarithromycin|Clarithromycin]]<ref name="pmid15708077">{{cite journal |vauthors=Pehlivan M, Pehlivan S, Onay H, Koyuncuoglu M, Kirkali Z | title = Can mycoplasma-mediated oncogenesis be responsible for formation of conventional renal cell carcinoma? | journal = Urology | volume = 65 | issue = 2 | pages = 411–414 | date = February 2005 | pmid = 15708077 | doi = 10.1016/j.urology.2004.10.015 }}</ref>) before the irreversible stage, the infected cells should return to normal.

==== Connections to cancer ''in vivo'' and future research ====

Epidemiologic, genetic, and molecular studies suggest infection and inflammation initiate certain cancers, including those of the prostate. ''M. genitalium'' and ''M. hyorhinis'' induce malignant phenotype in benign human prostate cells (BPH-1) that were not tumorigenic after 19 weeks of exposure.
<ref name="pmid19721714"/>

==== Types of cancer associated with ''Mycoplasma'' ====

Colon cancer: In a study to understand the effects of ''Mycoplasma'' contamination on the quality of cultured human colon cancer cells, a positive correlation was found between the number of ''M. hyorhinis'' cells present in the sample and the percentage of CD133-positive cells (a glycoprotein with an unknown function).<ref name="pmid 20353562">{{cite journal |vauthors=Mariotti E, Gemei M, Mirabelli P, D'Alessio F, Di Noto R, Fortunato G, Del Vecchio L | title = The percentage of CD133+ cells in human colorectal cancer cell lines is influenced by Mycoplasma hyorhinis infection | journal = BMC Cancer | volume = 10 | pages = 120–125 | date = March 2010 | pmid = 20353562 | doi = 10.1186/1471-2407-10-120 | pmc=2854114 | doi-access = free }}</ref>

Gastric cancer: Strong evidence indicates the infection of ''M. hyorhinis'' contributes to the development of cancer within the stomach and increases the likelihood of malignant cancer cell development.<ref name="pmid21062494">{{cite journal |vauthors=Yang H, Qu L, Ma H, Chen L, Liu W, Liu C, Meng L, Wu J, Shou C | title = Mycoplasma hyorhinis infection in gastric carcinoma and its effects on the malignant phenotypes of gastric cancer cells | journal = BMC Gastroenterology | volume = 10 | pages = 132–140 | date = November 2010 | pmid = 21062494 | doi = 10.1186/1471-230X-10-132 | pmc=2993648 | doi-access = free }}</ref>

Lung cancer: Studies on lung cancer have supported the belief that more than a coincidental positive correlation exists between the appearance of ''Mycoplasma'' strains in patients and the infection with tumorigenesis.<ref name="pmid21999143">{{cite journal |vauthors=Apostolou P, Tsantsaridou A, Papasotiriou I, Toloudi M, Chatziioannou M, Giamouzis G | title = Bacterial and fungal microflora in surgically removed lung cancer samples | journal = Journal of Cardiothoracic Surgery | volume = 6 | page = 137 | date = October 2011 | pmid = 21999143 | doi = 10.1186/1749-8090-6-137 | pmc=3212932 | doi-access = free }}</ref>

[[Medicine:Prostate cancer|Prostate cancer]]: p37, a protein encoded for by ''M. hyorhinis'', has been found to promote the invasiveness of prostate cancer cells. The protein also causes the growth, morphology, and gene expression of the cells to change, causing them to become a more aggressive phenotype.<ref name="pmid21663671">{{cite journal |vauthors=Urbanek C, Goodison S, Chang M, Porvasnik S, Sakamoto N, Li CZ, Boehlein SK, Rosser CJ | title = Detection of antibodies directed at M. hyorhinis p37 in the serum of men with newly diagnosed prostate cancer | journal = BMC Cancer | volume = 11 | issue = 1 | pages = 233–238 | date = June 2011 | pmid = 21663671 | doi = 10.1186/1471-2407-11-233 | pmc=3129326 | doi-access = free }}</ref>

Renal cancer: Patients with renal cell carcinoma (RCC) exhibited a significantly high amount of Mycoplasma sp. compared with the healthy control group. This suggests ''Mycoplasma'' may play a role in the development of RCC.<ref name="pmid15708077"/>

== See also ==
* [[Organization:International Organization for Mycoplasmology|International Organization for Mycoplasmology]] (IOM)
* Sexually transmitted disease
* Vaginal flora
* Vaginal infection
* [[Medicine:Vaginal disease|Vaginal disease]]
* Vaginal health
* [[Biology:Phytoplasma|Phytoplasma]]
* Smallest organisms
* [[Biology:List of bacterial orders|List of bacterial orders]]
* [[Biology:List of bacteria genera|List of bacteria genera]]

== References ==
{{Reflist}}

== External links ==
{{Medical resources
| ICD11           = {{ICD11|XN1W2}}
|  ICD10 = {{ICD10|A49.3}}
|  ICD9 = {{ICD9|041.81}}
}}
{{refbegin}}
* [http://emedicine.medscape.com/article/231470-overview Ureaplasma Infection: eMedicine Infectious Diseases]
{{refend}}

{{Bacteria classification|state=collapsed}}
{{Taxonbar|from=Q210975}}

[[Category:Mycoplasma| ]]
[[Category:Mycoplasmataceae]]
[[Category:Bacteria genera]]
[[Category:Rodent-carried diseases]]
[[Category:Infertility]]
[[Category:Bacterial vaginosis]]

{{Sourceattribution|Mycoplasma}}