High Prevalence of Cryptococcus neoformans and Isolation of Other Opportunistic Fungi From Pigeon (Columba livia) Droppings in Northeast Iran.

Cryptococcus neoformans is an opportunistic human pathogen that causes cryptococcosis, a life-threatening infection that usually manifests as meningoencephalitis in immunocompromised patients. Pigeon (Columba livia) droppings can spread pathogenic yeasts and mold fungi, such as C neoformans, in the environment. The objective of this study was to isolate C neoformans and other opportunistic fungi from feral pigeon droppings. One hundred twenty samples of feral pigeon droppings were suspended 1:10 in saline solution and then cultured. The fungi were identified by standard mycological techniques. Fungal contamination was detected in all examined samples. Yeast and mold fungi were isolated from 114 samples (95%) and 103 samples (85.8%), respectively, out of 120 samples. The highest frequency of yeast and mold fungi isolated from collected samples was C neoformans 77.5% and Rhizopus species 38.3%, respectively. Several types of fungi exist in pigeon droppings that can be spread in the environment and transmitted to children and elderly, as well as immunocompromised patients who are at increased risk of contracting opportunistic diseases.