GUT COLONIZATION OF MICE BY YEAST - EFFECTS OF METHYLPREDNISOLONE ANDANTIBIOTICS

Background/Aims: This study evaluated the effects of broad spectrum an tibiotics and methylprednisolone on the gut colonization of mice by C. albicans. Methodology: Male Crl:CD1 (ICR) BR mice, 3 months of age, w ere fed chow containing Candida albicans, while similar mice were fed regular chow. The gut of the Candida-fed mice was colonized by yeast. Groups of mice were subsequently treated for 10 days, with either ceft riaxone, ticarcillin-clavulanic acid, or methylprednisolone, each alon e or with the combination, of methylprednisolone and each antibiotic. Other Candida-colonized mice received normal saline, and non-colonized mice, serving as controls, received the same drugs and drug combinati ons or saline. Results: Candida-colonized mice treated with each antib iotic alone had significantly higher yeast counts in their stool, whil e those treated with methylprednisolone alone did not. Colonized mice treated with the combination, of each antibiotic with methylprednisolo ne had similar stool concentrations of Candida as mice treated with ea ch antibiotic alone. Saline did not change Candida in the stool concen tration, Yeast was not found in the stool of non-colonized mice treate d with the drugs under investigation or saline. Dissemination of Candi da did not occur in any mouse. Conclusions: Ceftriaxone and ticarcilli n-clavulanic acid significantly increase gut colonization of mice by y east, while methylprednisolone, either alone or in combination with th ese antibiotics, does not.