Treatment of intraabdominal infection.

Intraabdominal infections are derived from the flora of the gastrointestinal tract. The upper intestine, from the stomach to the mid-ileum, harbors a sparse microflora. The lower tract harbors a luxuriant flora comprised predominantly of anaerobic bacteria. Bacteriodes fragilis is the leading pathogen in anaerobic infections. In a recent nationwide survey of the susceptibility patterns of B. fragilis the most active beta-lactam antibiotics were cefoxitin, piperacillin and moxalactam. The other active drugs included metronidazole, clindamycin, and chloramphenicol. Many other penicillins and cephalosporins, as well as tetracyclines, showed poor activity. Clinical trials of antimicrobial drugs in intraabdominal infections generally have verified in vitro susceptibility tests. Before accepting a new drug for treating anaerobic infections, it is necessary to establish its efficacy in susceptibility tests, animal models and clinical trials.