[The importance of the use of antibiotics after surgical procedures on the abdominal cavity].

Surgical drainage is the most important treatment of infections of the abdomen. In severe cases supplementary antibiotic treatment is needed. Rational selection of antimicrobial therapy is based on a thorough knowledge of the invading pathogens. It should be taken into account that most abdominal infections are polymicrobic from which both aerobes, mainly enterobacteria, and anaerobes, mainly bacteria of the genus Bacteroides, are isolated. Such infections are synergistic processes, in which multiple bacteria act together to produce the disease. A group of 75 patients with infections following abdominal surgery was entered into the study. The in vitro results demonstrated that cefoxitin with or without an aminoglycoside or clindamycin plus an aminoglycoside was effective against the isolated bacteria. Cefoxitin was active against 94.7% of strains Bacteroides, against 98.1% of strains E. coli and against the majority of other (less frequent) bacteria, except against Pseudomonas aeruginosa, Enterococci and Peptococci. Clindamycin was active against anaerobic bacteria, and against some aerobic bacteria too; but it had no effect against E. coli and the majority of other enterobacteria. The aminoglycoside were effective against enterobacteria but they showed no activity against Gram-negative non-sporing anaerobes. The clinical outcome demonstrated that clindamycin plus an aminoglycoside and cefoxitin without or (sometimes) with an aminoglycoside were effective in the therapy of mixed abdominal infections.