Neisseria gonorrhoeae
"Chlamydia trachomatis" and "Neisseria gonorrhoeae" are usually the main cause of PID. Data suggest that PID is often polymicrobial. Isolated anaerobes and facultative microorganisms have been obtained from the upper genital tract. "N. gonorrhoeae" has been isolated from fallopian tubes, facultative and anaerobic organisms were recovered from endometrial tissues.