Efficacy of amphotericin B and fluconazole in the murine mycotie (Candida albicans) mastitis model

Abstract

The majority of animal models in antifungal tests use systemic infection and mortality and survival of infected animals as the experimental end—point. We developed a murine model of localised eandidiasis (murine myeotic mastitis) and assessed
its effectiveness through infection with Candida albicans followed by intraperitoneal administration of the antifungal drugs flunazole (FLU) and amphotericin B (AmB). Lactating BALB/cJ mice at day 5 post partum were inoculated (two glands) with a high dose of a human pathogenic C. albicans wild-type strain SC5314. Animals were treated immediately after infection with either FLU or AmB intraperitoneally for 4 days and euthanized by intracardiae exsanguination and cervical dislocation following anaesthesia with a mixture of Ketamine arid Xylazine. One infected gland was fixed in formalin and examined histopathologically and the other was homogenised for quantitative fungal cultures. There were severe changes in the untreated control animals (some animals had systemic candidiasis) compared to the treatment groups which had milder lesions. Fungal burden, determined as log [colony forming units (CFU)/g of mammary gland tissue], was similar in the untreated control group (n = 10) and FLU treated group (n = 6). However, there was significantly lower CFU/g in the mammary glands in AmB treated animals (n : 6) compared to both control and FLU treated animals (p < 0.05). The results indicate that AmB is more effective in prevention of murine mycotic mastitis than FLU and that the murine mycotic mastitis model may be an attractive animal model for antifungal chemotherapy studies.