Ureaplasma is a type of bacteria in the family of bacteria known as Mycoplasma. These bacteria are incredibly tiny (even in the context of microscopic bacteria) and are unique in that they lack a cell wall. Because the cell wall is the part of the bacteria attacked by a number of antibiotics, some common antibiotics such as those in the beta lactam family (for example, penicillin) are not effective against these bacteria. Mycoplasma organisms, when they infect humans, usually infect the respiratory or urogenital tracts. As the name implies, ureaplasma are generally found in the urogenital tract and are the cause of some urinary tract infections.
Ureaplasma infection is associated with non-gonococcal, non-chlamydial urethritis (inflammation of the urethra) in young men. The organism has also been found in 40-80% of asymptomatic sexually active young women. That is, they are sometimes present even in the absence of disease. When they do cause disease, the symptoms can include genital discharge or burning or pain with urination. Like any bacteria, these can be passed from person to person secondary to direct contact (that is, sexual contact can cause infection); however, they are not considered sexually transmitted infections (STIs) because there is not a high rate of transmission as there is with common STIs such as chlamydia and gonorrhea. It is also not an STI because it is often found in the genital tracts of normal, healthy individuals, whereas STIs almost always cause disease.
Treatment is with an antibiotic course (not a beta lactam!) such as with tetracycline or a fluoroquinolone, such as ciprofloxacin.