Anaerobic bacterial flora of intra-abdominal infections and their antimicrobial susceptibility pattern in Kuwait

Abstract

Clinical samples obtained from 200 patients with intra-abdominal infections were investigated for the presence of anaerobic bacteria. The majority of samples were from patients with appendicitis (108, 54%) followed by peritoneal abscess/peritonitis (37, 18.5%). A total of 153 anaerobes were isolated from 83 culture positive specimens with an isolation rate of 1.8 per sample. Ninety (59%) yielded Bacteroides fragilis group and B. fragilis stricto sensu accounted for half of them. Other isolates were 36 (23.5%) Prevotella species and 15 (9.8%)Peptostreptococcus micros . The susceptibility of the 153 isolates against eight antibiotics was determined by the E-test. All the isolates were susceptible to metronidazole, MIC₉₀s varying between 1-2 μg/mL. ThePrevotella spp., Peptostreptococcus spp., Fusobacterium spp. and Porphyromonas spp. were all susceptible to clindamycin (MIC₉₀s=0.25-2 μg/mL respectively), imipenem (MIC₉₀s=0.12-0.5μg/mL respectively) and meropenem (MIC₉₀=0.25 μg/mL each). About 25% of the B. fragilis group were resistant to clindamycin with MIC more than 256 μg/mL. Piperacillin-tazobactam also exhibited excellent in vitro activity against all the isolates (MIC₉₀=0.25 μg/mL).