Objective To compare how effective cornmeal agar incorporating caffeic acid(CACA)and black rice agar are at isolating Cryptococcus neoformans from pigeon droppings. Methods Sterile bamboo sticks were used to randomly collect pigeon droppings from a pigeonry.A suspension was created from 0.6g of pigeon droppings and 10ml of sterile normal saline,and plates were then separately furnished with 100μl of CACA and black rice agar.The shape and color of colonies were observed and mycelial morphology was examined using an optical microscope.The URA gene was amplified using the specific primers CN4 and CN5.The number of positive strains was counted in the 2 culture media. ResultsC.neoformans colonies in the black rice agar were tan in color and moist,like glue.Twenty three strains of C.neoformans were isolated at a rate of 32.86%.C.neoformans colonies in CACA were smaller in size than the colonies on the black rice agar.The colonies on CACA were brown and dry.Eleven strains of C.neoformans were isolated from the medium at a rate of 15.71%.C.neoformans was isolated from black rice agar at a significantly(P0.05)higher rate than from CACA.Fewer plates with CACA were covered with filamentous fungal growth and plates with CACA had less contamination.India ink staining revealed round or oval cells and a thick capsule when C.neoformans was observed under an optical microscope,and PCR amplification yielded products in target bands. Conclusion Black rice agar was better as a selective medium than CACA.

Objective:To investigate the positive rate of Cryptococcus neoformans in pigeon droppings in Dali and provide a basis for effectively avoiding its infection. Methods: A black rice culture medium was used for isolation and identification of Cryptococcus neoformans in 140 pigeon droppings. Results:46 strains of Cryptococcus neoformans were isolated and urea tests all proved positive. Conclusion:The positive rate of Cryptococcus neoformans in pigeon droppings in Dali was very high(32.9%).

Objective To isolate and identify Cryptococcus neoformansfrom pigeon droppings in parts of Yunnan Province and to investigate the rate at which those droppings tested positive for C.neoformans. Methods Sterile bamboo sticks were used to randomly collect pigeon droppings from a pigeonry.A suspension was created from 0.6g of pigeon droppings and 10 ml of sterile normal saline,and plates were coated with 100μl of black rice agar medium.The shape and color of colonies were observed and mycelial morphology was examined using an optical microscope.The plates were also used to isolate C.neoformans from pigeon droppings.The URA5 gene was amplified using the specific primers CN4 and CN5,and the serotype and mating type were verified using specific primers. Results C.neoformans was isolated from152 of 473total specimens.On average,C.neoformans was isolated at a rate of 32.13%.C.neoformans was isolated in Dali at a rate of 26.08%,in Zhaotong at a rate of 30.05%,in Qujing at a rate of 81.81%,and in Lincang at a rate of 37.03%.There were significant differences(χ2=41.87,P0.01)in the rates at which C.neoformans was isolated from these 4locations. Conclusion Pigeon droppings in Yunnan tested positive for C.neoformans at a relatively high rate(32.13%).Pigeon droppings in different areas tested positive for C.neoformans at different rates.