Isolation and identification of yeast from 143 samples of pigeon droppings

Objective To study the diversity of yeast and the carriage rate of Cryptococcus neoformans in pigeon droppings. Methods Yeast strain isolation and identification from 143 pigeon dropping samples were conducted by using Sabouraud Dextrose Agar medium, CHROM Agar Candida medium, DOPA medium, Christensen's medium, API 20C AUX and blast analysis of ITS sequence. Results Totally 123 yeast strains were isolated from the 143 samples, including 46 strains of Cryptococcus (6 strains of Cryptococcus neoformans, 4.87%), 33 strains of Rhodotorula, 32 strains of Filobasidium, 6 strains of Candida, 3 strains of Debaryomyces hansenii, 3 strains of Saccharomyces, accounting for 37.40%, 26.83%, 26.02%, 4.87%, 2.44% and 2.44%, respectively. Conclusion Most yeasts in pigeon dropping are non-pathogenic, human infection is occasionally reported. The isolation rate of Cryptococcus neoformans in pigeon droppings in our study was much lower than that reported by others (20%-50%). It is necessary to take disinfection measures in pigeon raising household to protect the health of young children, elderly people and immunosuppression patients.