My.co.plas'ma. Gr. masc. n.
myces
a fungus; Gr. neut. n.
plasma
something formed or molded, a form; N.L. neut. n.
Mycoplasma
fungus form.
Tenericutes / Mollicutes / Mycoplasmatales / Mycoplasmataceae / Mycoplasma
Pleomorphic
cells, 300–800 nm in diameter, varying in shape from spherical, ovoid or flask‐shaped, or twisted rods, to slender branched filaments ranging in length from 50 to 500 nm.
Cells lack a cell wall
and are bounded by a single plasma membrane. Gram‐stain‐negative due to the absence of a cell wall. Some have a complex internal cytoskeleton. Some have a specific
tip structure
that mediates attachment to host cells or other surfaces.
Usually nonmotile
, but gliding motility has been demonstrated in some species.
Aerobic or facultatively anaerobic
. Optimum growth at 37°C is common, but permissive growth temperatures range from 20 to 45°C.
Chemo‐organotrophic
, usually using either sugars or arginine as the major energy source.
Require cholesterol
or related sterols for growth. Colonies are usually less than 1 mm in diameter. The typical colony has a
fried‐egg appearance
. The
genome size
of species examined ranges from
580 kbp to about 1350 kbp
. The codon UGA encodes tryptophan in all species examined.
Commensals or pathogens
in a wide range of vertebrate hosts.
DNA G
+
C content
(
mol
%): 23–40.
Type species
:
Mycoplasma mycoides
(Borrel, Dujardin‐Beaumetz, Jeantet and Jouan 1910) Freundt 1955, 73 (
Asterococcus mycoides
Borrel, Dujardin‐Beaumetz, Jeantet and Jouan 1910, 179).