Mycoplasma genitalium is a small parasitic bacterium that lives on the ciliated epithelial cells of the primate genital and respiratory tracts. It is the smallest known free-living bacterium. Up until 2002 it was also considered to be the organism with the smallest genome.
M. genitalium was isolated in 1980 from urethral specimens of two male patients with non-gonococcal urethritis. Infection is fairly common and can be transmitted between partners during unprotected sex. It can be treated with antibiotics although its role in genital disease is still unclear.
The genome consists of 521 genes in one circular chromosome of 582, 970 base pairs. Infections include Urethritis, discharge, burning while urinating, arthritis, vaginal itching, and pain during intercourse. Infection is associated with bacterial vaginosis. If it persists it is suspected to cause pelvic inflammatory disease.