The aim of this study was to study the effects of metronidazole on the establishment of oral candidosis and Candida albicans
colonization in the oral cavity of rats. Forty-eight male rats, negative for yeasts in the oral cavity, were used in the study. The rats were inoculated with a suspension of Candida albicans
and treated with metronidazole or plain water (control group). The rats of the candidosis experimental group were sacrificed 7, 15, or 30 days after inoculation and their tongues were analyzed by light microscopy. Colonization by Candida albicans
was evaluated 1, 2, 5 and 7 days after inoculation and progressively at 15-day intervals, with a total of 18 collections. The results demonstrated the development of candidosis on the tongue dorsum was similar between the Control and Metronidazole groups for each sacrifice period. However, the colonization results showed that yeasts were recovered in the Metronidazole group in greater numbers than in the Control group after the 37th
day of the experiment (6th
collection). According this, the long term metronidazole therapy favored the colonization of C. albicans
in the oral cavity of rats.