Which of the following mycoplasmas has been implicated as a cause of nongonococcal urethritis (NGU)?

Ureaplasma urealyticum has been associated with nongonococcal urethritis (NGU) as well as infeility. Mycoplasma pneumoniae is the etiologic agent of primary atypical pneumonia. M. hominis, although isolated from up to 30% of patients with NGU, has yet to be implicated as a cause of that disease. M. fermentans has on rare occasions been isolated from the oropharynx and genital tract. M. mycoides causes bovine pleuropneumonia. Note: Ureaplasmas can be distinguished from mycoplasmas by their ability to produce the enzyme urease, which degrades urea to ammonia and carbon dioxide. Ref: Brooks G.F., Carroll K.C., Butel J.S., Morse S.A., Mietzneron T.A. (2010). Chapter 25. Mycoplasmas & Cell Wall-Defective Bacteria. In G.F. Brooks, K.C. Carroll, J.S. Butel, S.A. Morse, T.A. Mietzneron (Eds), Jawetz, Melnick, & Adelberg's Medical Microbiology, 25e.