Identification of Clinically Relevant Yeasts from Avian Isolates Using API ID32C, MALDI-TOF MS, and ITS Sequencing:...

Wild and synanthropic birds harbour a diverse range of yeasts, including species of recognised clinical relevance. Given their close interaction with human activities, these birds represent a valuable source for investigating environmental yeasts and assessing the performance of identification methods. We investigated yeasts recovered from cloacal and crop samples of birds from Gran Canaria and compared routine identification methods with molecular sequencing. Twenty-four isolates were examined by biochemical profiling (API ID32C) and MALDI-TOF MS. Molecular identification based on ITS sequencing was carried out only for the sixteen isolates for which the two routine methods yielded discordant results, allowing resolution of their taxonomic identification. Phenotypic and proteomic methods showed limited agreement at the species level (8/24; 33.3%), with 16 discordant identifications resolved by sequencing. Pigeon isolates were dominated by members of the Kazachstania telluris complex, chiefly K. bovina (11/24; 45.8%), while partridges yielded taxa of clinical importance, including Candida parapsilosis and Pichia kudriavzevii (formerly Candida krusei). Rhodotorula mucilaginosa, Debaryomyces spp., and Saccharomyces cerevisiae were also detected. Comparative tests confirmed significant host-associated differences in species distribution (p < 0.05), and Cohen's kappa indicated substantial agreement between API and MALDI-TOF at the genus level when benchmarked against ITS (κ = 0.71), although concordance was lower at the species level. In conclusion, these findings strengthen the case for integrating sequencing into diagnostic workflows, highlight the potential One Health relevance of yeast carriage by wild birds, and underscore the need for targeted surveillance at urban and game-handling interfaces where human exposure is likely.