Sustained gastrointestinal colonization and systemic dissemination by Candida albicans, Candida tropicalis and Candida parapsilosis in adult mice

The ability of nine clinical isolates of Candida species (three C. albicans , three C. tropicalis and three C. parapsilosis) to colonize and invade the gastrointestinal (GI) tract of adult male CD-1 OCR) mice was determined. T he effect of dietary tetracycline plus glucose supplementation on colonizat ion was evaluated. Strains were intragastrically inoculated. Tetracycline a nd glucose altered substantially aerobic flora, especially streptococci (av erage fall 1.1 +/- 0.3 log(10) CFU/g, p < 0.01 by the Student's t test). At two weeks after oral challenge, sustained and high colonization of GI trac t by Candida (mean 5,28 +/- 0.18 log(10) CFU/g, p < 0.01) was achieved in a ll mice receiving glucose-tetracycline supplementation, excepting in animal s inoculated with one of C. tropicalis isolates. Histologic sections of the stomachs revealed multiple intraepithelial micro-abscesses associated with hyphae in the region of the cardial-atrium fold. Under immunosuppression, systemic spread of C. albicnns and C. tropicalis was observed in 62% and 24 % of animals receiving dietary supplementation respectively. Dissemination was not noted for C. parapsilosis isolates. We have developed a simple and inexpensive murine model of sustained colonization of GI tract. This model could be useful for analyzing prophylaxis, treatment and diagnosis of syste mic Candida infections and for evaluating virulence of strains. (C) 2000 El sevier Science Inc. All rights reserved.