In many intra-abdominal infections, aerobic or facultative organisms such as Escherichia coli , Klebsiella , Proteus , and enterococci are also present. Thus, antibiotic therapy often consists of combinations of drugs directed at several organisms. The normal vagina and cervix harbor the same range of anaerobic bacteria as is found in the gastrointestinal tract. These bacteria are frequently implicated in nongonococcal infections of the female genital tract, including vulvovaginal and Bartholin's gland abscesses, endometritis, salpingitis, tubo-ovarian abscesses, and pelvic peritonitis. A similar range of organisms cause infections after gynecologic surgery, parturition, and abortion.
Anaerobes play an important role in chorioamnionitis.
Anaerobic infections of the skin and soft tissues, although less common, can be of unrivaled clinical severity. In addition to clostridial species, other anaerobes can participate in these processes. Multiple aerobic and anaerobic organisms can cause synergistic skin infections such as Meleney's progressive synergistic gangrene, necrotizing fasciitis, or Fournier's gangrene. In addition to broad-spectrum antibiotics, extensive surgical drainage is mandatory. Mortality is high, even with treatment.