Effects of erythromycin and gentamicin in experimental peritonitis

Erythromycin and gentamicin were used to analyse the concept of bacterial synergy in an experimental model of acute appendicitis. Erythromycin given orally suppressed the aerobic flora other than the Enterobacteriaceae. When given by injection, a notable reduction in the counts of bacteroides and other anaerobic Gram-negative bacteria was also achieved. The addition of gentamicin, itself inactive against bacteroides, resulted in their total suppression. The implications of these findings are discussed.