Alterations in the human oropharyngeal microflora related to therapy with aztreonam, moxalactam and ampicillin plus sulbactam.

Abstract

33 patients undergoing colorectal surgery were treated prophylactically with aztreonam (19 patients), moxalactam (10 patients) and ampicillin plus sulbactam (4 patients). The effect on the normal oropharyngeal microflora and new colonization of oropharynx were studied during and after the treatment. Aztreonam had minor effect on the normal flora but induced colonization with staphylococci. Moxalactam suppressed gram-negative aerobic and anaerobic bacteria and promoted colonization with Candida albicans. Ampicillin plus sulbactam had marked effect on the normal flora and suppressed aerobic as well as anaerobic bacteria. New colonization with enteric gram-negative rods or fungi was observed in all patients.