Isolation and identification of Candida tropicalis in sows with fatal infection: a case report

BACKGROUND: Candida is the common conditionally pathogenic fungus that infected human and animal clinically. C. tropicalis had been isolated from the skin and hair of healthy pigs, but with no report of fatal infection in gastrointestinal diseases. CASE PRESENTATION: In a pig farm in Henan Province of China, about 20 % of pregnant and postpartum sows suffered from severe gastrointestinal diseases, with a mortality rate higher than 60 % in the diseased animals. The sows had gastrointestinal symptoms such as blood in stool and vomiting. Necropsy revealed obvious gastric ulcers, gastrointestinal perforation, and intestinal hemorrhage in the gastrointestinal tract, but no lesions in other organs. The microbial species in gastric samples collected from gastric ulcer of the diseased sows then was initially identified as Candida by using routine systems of microscopic examination, culture characteristics on the medium Sabouraud dextrose agar medium. The fungus was further identified as C. tropicalis by species-specific PCR and sequencing. This study revealed an infection of C. tropicalis in sows through gastrointestinal mucosa could cause fatal digestive system disease and septicemia. CONCLUSIONS: For the first time, a strain of C. tropicalis was isolated and identified from the gastric tissue of sows with severe gastrointestinal diseases. PCR and sequencing of ITS-rDNA combined with morphology and histopathological assay were reliable for the identification of Candida clinically.