Efficacy of antibacterial drugs in mice with complex infection by Candida albicans and Escherichia coli

We investigated the effect of seven antibacterial antibiotics: kanamycin, g entamicin, tetracycline, minocycline, ampicillin, piperacillin and cefotaxi me, on survival of mice infected sequentially with a lethal dose of Candida albicans and a sublethal dose of Escherichia coli. The mortality of C. alb icans-infected mice was facilitated by the superinfection with E. coli. Whe n administered to mice with C. albicans/E. coli complex infection, aminogly cosides and tetracyclines significantly prolonged the survival period as co mpared with the infected and untreated controls. The recovery of viable cou nts of E. coli from the renal tissues was rapidly reduced by the treatment with gentamicin or minocycline, compared to the untreated control. Thus it was concluded that nullification by the treatment with aminoglycosides or t etracyclines of the enhancing effect of E. coli superinfection on the letha lity of C. albicans-infected mice is due to early elimination of E. coli fr om the kidney.