Characterization, enzymatic activity and biofilm formation of Candida species isolated from goat milk.

BACKGROUND: Data regarding yeast microbiota in goat milk is scarce.

AIMS: To isolate and identify species of the genus Candida in milk samples from clinically healthy goats, and evaluate their enzymatic activity and biofilm formation.

METHODS: 1092 milk samples from clinically healthy goats were collected and processed. The yeast isolates were identified by phenotypic, methods and their enzymatic activity (phospholipase, hemolysin and protease) and biofilm formation evaluated.

RESULTS: We obtained 221 Candida isolates belonging to six species: Candida kefyr (35.7%), Candida guilliermondii (33%), Candida famata (23.5%), Candida glabrata (5.9%), Candida albicans (1.35%) and Candida parapsilosissensu lato (0.45%). Protease activity was detected in all Candida species while hemolysin activity was only present in C. kefyr, C. guilliermondii, C. famata and C. albicans. Only C. albicans showed phospholipase activity. With the exception of C. parapsilosis sensu lato, all Candida species formed biofilm, with 60.19% of the isolates being poor producers, 9.93% moderate producers, and 1.35% strong producers.

CONCLUSIONS: The milk of clinically healthy goats contains several species of the genus Candida that could play a role as opportunistic pathogens in mastitis.