Murine yeast gut flora affected by tetracycline, metronidazole and norfloxacin.

Three-month old, male Crl:CD1(ICR) BR mice, were fed food containing Candida albicans, while other mice of the same type were fed regular food. Both groups of mice were subsequently given orally either antibiotics or normal saline for a 10-day period. The stools of all mice were cultured before, at the end, and one week after the end of the antibiotic treatment, to determine the level of gut colonization by the yeast. The mice fed Candida and treated with antibiotics had substantially higher Candida counts in their stools than control mice fed C. albicans and treated with saline. The concentrations of Candida in the stools of mice treated with tetracycline were much higher when compared to those of mice treated with metronidazole and norfloxacin. Tetracycline was associated with a statistically significant increase of gastrointestinal Candida colonization. Yeast was not found in the stools of mice fed regular food and treated with antibiotics or saline. Histopathologic examination did not reveal dissemination of Candida in the visceral organs of any mouse.