Multilocus sequence typing of Candida albicans isolates from wild and farm animals from southern Italy

Candida albicans is the leading cause of invasive candidiasis in humans and animals and is recognized as a critical priority pathogen by the World Health Organization. However, despite the growing attention paid to this pathogen, few studies have investigated its genetic diversity, population structure, and evolution in non-human hosts. We report, for the first time, genotyping data from C. albicans isolates recovered from wild and farm animals in Italy, highlighting the potential role of animal hosts in C. albicans evolution and transmission. Twenty-seven Candida albicans isolates collected from faecal samples of laying hens (n = 15), wild boars (Sus scrofa) (n = 9), and three from different lizard species (Tarentola mauritanica, Chalcides ocellatus, Podarcis filfolensis) were characterized by multilocus sequence typing (MLST), based on seven housekeeping genes (i.e., AAT1a, ACC1, ADP1, MPIb, SYA1, VPS13, and ZWF1b). Of 27 diploid sequence types (DSTs) identified, 22 (81.5 %) were novel. DNA mutations were most frequent in the VPS13 gene while little genetic variation was observed in the ACC1 gene. The C. albicans DSTs from laying hens, lizards and wild boars clustered with clinical isolates from humans and domestic and wild animals of different geographical provenance. The phylogenetic tree analysis reveals intricate and interconnected relationships, highlighting the complex evolutionary dynamics of C. albicans. Global optimal eBURST analysis revealed 16 genotypes (59 %) were classified as singletons, while the remaining 11 genotypes (41 %) were placed in 6 different clonal complexes, none of which were exclusively composed with isolates of animal origin. Our data showed a close genetic relationship between human clinical and animal isolates suggesting potential cross-transmission of C. albicans between animals and the community.