Gastrointestinal and systemic candidosis in immunocompromised mice

Area of Science:

• Mycology
• Immunology
• Infectious Diseases

Background:

• Candida albicans commonly colonizes the gastrointestinal (GI) tract.
• In non-immunocompromised mice, C. albicans primarily localizes to the stomach and intestines.
• Hyphal elements are associated with the stomach's stratified squamous epithelium.

Purpose of the Study:

• To investigate the effect of immunosuppression on C. albicans colonization and dissemination in mice.
• To establish an animal model for studying invasive candidiasis in immunocompromised hosts.
• To explore methods for preventing C. albicans dissemination and testing anti-Candida drug efficacy.

Main Methods:

• Oral-intragastric inoculation of C. albicans in 6-day-old mice.
• Immunosuppression induced by cyclophosphamide and cortisone acetate.
• Sacrifice at 20 days post-challenge for tissue culture and histological examination.

Main Results:

• Immunocompromised mice showed a high density of invasive hyphae in the stomach.
• A 100-fold increase in C. albicans colony-forming units (c.f.u.) in stomach homogenates compared to controls.
• Positive cultures for C. albicans in esophagus and organs of immunocompromised mice, with abscesses in liver, lungs, and kidneys.
• Delayed immunosuppression resulted in less systemic spread.

Conclusions:

• Immunosuppression significantly enhances C. albicans invasion and systemic spread from the GI tract.
• The developed animal model mimics focal hepatic candidosis seen in immunocompromised patients.
• This model is valuable for developing strategies to prevent candidiasis dissemination and evaluate antifungal treatments.