Ecological impact of antimicrobial prophylaxis on intestinal microflora in patients undergoing colorectal surgery.

: During recent years the impact of different antimicrobial agents on the intestinal microflora in patients undergoing colorectal surgery has been investigated by our research group. Thus the effects on the microflora by parenteral administration of piperacillin, cefoxitin, cefbuperazone, moxalactam, aztreonam, imipenem, ampicillin + sulbactam, clindamycin, tinidazole, ciprofloxacin and ofloxacin have been studied. Pronounced changes were observed in the aerobic microflora in patients receiving ciprofloxacin and ofloxacin, in the anaerobic microflora in patients receiving clindamycin and tinidazole and in both the aerobic and anaerobic microflora in those patients receiving piperacillin, cefoxitin, cefbuperazone, moxalactam, aztreonam, imipenem and ampicillin + sulbactam. Postoperative infections were observed in patients receiving piperacillin (2), ampicillin + sulbactam (1), cefoxitin (1), aztreonam (3), tinidazole (6), clindamycin (5) and ofloxacin (5). In the patient groups receiving cefbuperazone, moxalactam, imipenem and ciprofloxacin, no postoperative infections occurred.