Recovery of anaerobic bacteria from clinical specimens in 12 years at two military hospitals.

Examination of 15,844 clinical specimens submitted over 12 years (1973 to 1985) to the anaerobic microbiology laboratories in two military hospitals demonstrated the recovery of anaerobic bacteria in 4,458 (28.1%) specimens. The specimens yielded 6,557 anaerobic isolates (1.47 isolates per specimen). Bacteroides spp. accounted for 43% of all isolates; anaerobic gram-positive cocci, 26%; Clostridium spp., 7%; and Fusobacterium spp., 4%. Bacteroides spp. predominated in abscesses, obstetrical and gynecological (OBG) infections, abdominal infections, cysts, wounds, and tumors. Members of the Bacteroides fragilis group accounted for 44% of all Bacteroides spp., and of them, B. fragilis was mostly isolated in abscesses, wounds, abdomen, and blood. Pigmented Bacteroides spp. accounted for 21% of all Bacteroides sp. isolates and were mostly isolated in sinus, eye, chest, bone, and ear infections. Bacteroides melaninogenicus accounted for 42% of this group's isolates. Bacteroides bivius accounted for 9% of Bacteroides spp., and most isolates were found in OBG infections. Anaerobic gram-positive cocci were mostly isolated in OBG infections, abscesses, and wounds. The predominant anaerobic gram-positive cocci were Peptostreptococcus magnus (18%), Peptostreptococcus asaccharolyticus (17%), Peptostreptococcus anaerobius (16%), and Peptostreptococcus prevotii (13%). Clostridium spp. were mostly isolated from wounds, abscesses, abdominal infections, and blood. The predominant strain was Clostridium perfringens (48%). Fusobacterium spp. were recovered in abscesses and abdominal and OBG infections. The predominant isolate was Fusobacterium nucleatum (47%). These data illustrate the relative frequency of the different anaerobic bacteria in a variety of infections and demonstrate the predominance of certain isolates at different sites.