General Information: Causative agent of contagious pleuropneumonia in livestock. This genus belongs to the class Mollicutes (phylum Tenericutes), a taxonomic group of small (0.3-0.8 micron diameter) monoderm bacteria characterized by the lack of cell walls, reduced genome sizes, and obligate parasitic lifestyles (Krieg et al., 2010). Over 120 obligate parasitic species found in a wide spectrum of hosts, including humans, animals, insects and plants. Infection typically proceeds through the attachment of bacteria to host cells via assorted adhesins or, in some species, through highly specialized surface protein appendages. In some cases, subsequent invasion of host cells results in a prolonged intracellular persistence that may cause lethality. These adaptive strategies are involved in host cell attachment and invasion, as well as immune evasion. Although mycoplasmas are dependent on their association with eukaryotic host tissue in nature, most can be cultivated axenically if their fastidious growth requirements are met. Nearly all mycoplasmas derive energy only from glycolytic pathways, whereas some can hydrolyze arginine. Assigned to the genus Mycoplasma by historic taxonomic precedent, organism in the Mycoplasma mycoides phylogenetic cluster are in fact more closely related to other genera in the Mollicutes (Krieg et al., 2010).