Effect of ketoconazole, itraconazole and fluconazole on the gastrointestinal colonization of mice by Candida albicans

Cr1:CD1 (ICR) BR mice were colonized in the gastrointestinal (GI) tract wit h Candida albicans. This strain was susceptible to ketoconazole (MIC=0.25 m ug/ml), itraconazole (minimum inhibitory concentration, MIC=0.25 mug/ml), a nd fluconazole (MIC=4 mug/ml). Subsequently the animals received monotherap y with ketoconazole by mouth (equivalent to human dose of 2.9 mg/kg/day), o r itraconazole by mouth (equivalent to human dose of 2.9 mg/kg/day), or flu conazole either subcutaneously (equivalent to human dose of 2.2 mg/kg/day), or by mouth (equivalent to human dose of 2.2 mg/kg/day), for 10 days. Quan titative stool cultures at the end and one week after the end of treatment revealed that all three azoles caused a small and statistically non signifi cant reduction of C. albicans concentration in the stools. The different ro ute of administration of fluconazole did not produce different results. In conclusion, these azoles, used at the present doses and schedules, have min imal effect on murine GI colonization by this strain of C. albicans which i s susceptible but with rather increased MICs.