A group of micro-organisms which plays a larger part in the causation of disease than was at one time suspected. One of them, Ureaplasma urealyticum, is now recognised as a cause of chronic prostatitis and might also be responsible for some urethral irritation or vaginal discharge in women. Treatment, if required, is with docycycline (see under PROSTATE GLAND, DISEASES OF), NON-SPECIFIC URETHRITIS (NSU) – see also URETHRA, DISEASES OF AND INJURY TO – and INFERTILITY.