Mycoplasmataceae is a family of

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

in the order

Mycoplasmatales Mycoplasmatales is an order of bacteria in the class Mollicutes. The order consists of the families Spiroplasmataceae and Mycoplasmataceae. As currently (2025) defined by LPSN, this class is synonymous to Entomoplasmatales, a class originally in ...

. This family consists of ''

Mycoplasma ''Mycoplasma'' is a genus of bacteria that, like the other members of the class ''Mollicutes'', lack a cell wall, and its peptidoglycan, around their cell membrane. The absence of peptidoglycan makes them naturally resistant to antibiotics ...

'' and four more genera. In 1967, the order Mycoplasmatales was incorporated into the class Mollicutes. Sexually-transmitted species and ''Ureaplasma'' are classified in

Mycoplasmoidaceae Mycoplasmoidaceae is a family of bacteria under the order Mycoplasmoidales. It contains the genera '' Eperythrozoon'', '' Malacoplasma'', '' Mycoplasmoides'', and ''Ureaplasma''. Members infect animals, including humans. Before 2018, they were k ...

since 2018.

Taxonomy

''Mycoplasma''

'' is a

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 ...

that lack a

cell wall A cell wall is a structural layer that surrounds some Cell type, cell types, found immediately outside the cell membrane. It can be tough, flexible, and sometimes rigid. Primarily, it provides the cell with structural support, shape, protection, ...

and possess a three-layered cellular membrane. They can be

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

saprotrophic Saprotrophic nutrition or lysotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed (dead or waste) organic matter. It occurs in saprotrophs, and is most often associated with fungi ...

. Several species formerly classified as ''Mycoplasma'' are sexually transmitted and

pathogen In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...

ic in humans (see ). Others are found on cats, dogs, and barnyard fowl.

Taxa infecting insects

A few genera infecting insects were added to this family in 2019 using molecular phylogenetic evidence. These genera were originally called Entomoplasmataceae and believed to be monophyletic.Revised taxonomy of the class Mollicutes: proposed elevation of a monophyletic cluster of arthropod-associated mollicutes to ordinal rank (Entomoplasmatales ord. nov.), with provision for familial rank to separate species with nonhelical morphology (Entomoplasmataceae fam. nov.) from helical species (Spiroplasmataceae), and emended descriptions of the order Mycoplasmatales, family Mycoplasmataceae. Tully J.G., Bove J.M., Laigret F. and Whitcomb R.F., Int. J. Syst. Bacteriol., 1993, volume 43, pages 378-385
article
However, work in 2019 found it to be a paraphyletic group by the exclusion of ''Mycoplasma''. The two original genera (''

Mesoplasma ''Mesoplasma'' is a genus of bacteria belonging to the class Mollicutes. Mesoplasma is related to the genus Mycoplasma but differ in several respects. Phylogeny The currently accepted taxonomy is based on the List of Prokaryotic names with Stan ...

'' and ''

Entomoplasma ''Entomoplasma'' is a mollicute bacteria genus. '' Entomoplasma freundtii'' (now a member of the genus ''Williamsoniiplasma'') can be isolated from the green tiger beetle ('' Cicindela campestris'', Coleoptera: Cicindelidae). Phylogeny The curr ...

'') were also found to be in need of breaking up due to polyphyly. As a result five genera were finally added: * ''

'' (formerly "Mesoplasma clade I") * ''

'' (formerly "Entomoplasma clade I") * '' Tullyiplasma'' (formerly "Mesoplasma clade II") * '' Williamsoniiplasma'' (formerly "Entomoplasma clade II") * '' Edwardiiplasma'' (formerly "Mesoplasma clade III")

Phylogeny

The currently accepted taxonomy is based on the

List of Prokaryotic names with Standing in Nomenclature List of Prokaryotic names with Standing in Nomenclature (LPSN) is an online database that maintains information on the naming and taxonomy of prokaryotes, following the taxonomy requirements and rulings of the International Code of Nomenclatu ...

(LPSN) and

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is lo ...

(NCBI).

References

External links

Ureaplasma Infection: eMedicine Infectious Diseases
{{Authority control Mollicutes Bacteria families