Abstract
Wound cultures from 54 patients with infections after gastrointestinal surgery were examined. Cultures from wounds after surgery on the upper gastrointestinal tract grew few organisms, mainly aerobic gram-positive cocci. Cultures from wounds on the lower gastrointestinal tract grew strains of bacteria, aerobic and anaerobic gram-negative rods dominating. Indirect immunofluorescence studies on acute and convalescent phase sera showed significant immune response against Bacteroides fragilis in a majority of cases. Immune response against anaerobic cocci was seldom found. Very high antibody titres against Clostridium perfringens were often found, both in patients' and control sera.