ackground: The aim of our study was to evaluate the incidence of fungi in the stomach in patients with gastric ulcer and chronic gastritis in comparison to healthy humans, and to identify the fungus species isolated from these patients and their susceptibility to antifungal agents. We also assessed the coincidence of the presence of antifungal antibodies and fungal mannan antigen in serum with the concentration of fungi in the stomach.
Material/Methods: We investigated 293 patients, aged 20-80, who visited the Gastroenterology Outpatient Clinic at the Jagellonian University's Collegium Medicum in Cracow, complaining of dyspeptic symptoms or clinical manifestations of ulcer disease. The examinations included endoscopy of the upper part of the alimentary tract with sampling of gastric contents, as well as surface brushing and biopsy from the bottom of the ulceration for mycological analysis. Also, biopsy specimens from the margin of the ulceration or inflammatory mucosa were collected for histological examination and urease testing.
Results: Gastric mucosa and stomach contents are often an area of fungal colonization, which was detected in 54.2% of the gastric ulcer cases and 10.3% of the chronic gastritis cases. The most frequently isolated fungus species was Candida albicans, although other fungi, previously considered rare or uncommon, were also found. A difference in growth in vitro between the C. albicans, C. tropicalis and C. lusitaniae strains was discovered: C. albicans and C. tropicalis grew from pH 2.0, while C. lusitaniae grew from pH 3.0. This finding suggests differentiation in the properties of these fungi.
Conclusions: The lack of correlation between the concentration of fungi, the titre of antifungal antibodies and the presence of fungal antigen in serum suggests that fungal colonization is secondary in nature.

Keywords: Candida albicans, fungal colonisation, gastric ulcer, chronic gastritis, myco-serology