Anaerobic bacteria which are flora members of humans and which are found widespread in nature had been attracting attention of scientists since 19th century as causative agents of serious infections. Although antibiotic resistance is an important problem among these bacteria, antibiotic susceptibility testings haven't been standardized yet.

Species identification and antibiotic susceptibilities of anaerobic bacteria, isolated from various materials which had been referred to our laboratory for the last 7 years are evaluated in this study. 131 anaerobic bacteria isolated from a total of 1503 materials were identified by conventional biochemical tests and API Rapid ID32A (Bio Merieux). Antibiotic susceptibilities were searched by API ATB ANA (Bio Merieux). 60 (47.2%) Bacteroides spp., 37 (29.1%) Peptostreptococcus spp., 6 (4.7%) Gemella spp., 6 (4.7%) Clostridium spp., 6 (4.7%) Propionibacterium spp., 4 (3.2%) Capnocytophaga spp., 4 (3.2%) Prevotella spp., 4 (3.2%) Actinomyces spp., 2 (1.6%) Veillonella spp., 1 (0.8%) Fusobacterium spp., 1 (0.8%) Bifidobacterium spp. were identified.

It has been shown that resistance rates for penicillin, clindamycin, and metronidazole are increasing in Bacteroides and Peptostreptococcus strains and imipenem and beta-lactamase inhibitory agents are the most efficacious antimicrobials.

Treatment of infections caused by anaerobic microorganisms is generally empirical at the beginning. Determination of susceptibility patterns of hospitals periodically, will help the clinicians to decide about the antibiotic choice when they meet these kind of infections.