Mycoplasmas are bacteria that lack a cell wall and are the smallest prokaryotes (0.2–0.8 μm in diameter). They have complex nutritional requirements but will grow on specialized artificial medium containing serum. Growth in broth and on agar media is slow (5–21 days), and the small (0.1–1 mm diameter) colony morphology typically has a "fried egg" appearance under low magnification. Mycoplasmas do not survive for more than a few days outside the host and are vulnerable to common disinfectants.
Several Mycoplasma species have been isolated from avian hosts; M gallisepticum, M synoviae, M meleagridis, and M iowae are the most important. Each has distinctive epidemiologic and pathologic characteristics.
Last full review/revision September 2013 by David H. Ley, DVM, PhD