Isolation of Cryptococcus neoformans from pigeon droppings in Ahwaz, Iran

Abstract

Aim: Cryptococcus neoformans is an opportunistic human pathogen that causes cryptococcosis, a life-threatening infection that is usually manifested as menigeoencephalitis mainly in immunocompromised patients. The objective of this study was to evaluate the presence of Cryptococcus neoformans in Ahwaz, Iran. Materials and methods: Sixty-five samples of pigeon droppings were collected from 10 different regions in Ahwaz. Each sample was suspended 1:10 in saline solution and then cultured in Sabouraud's dextrose agar medium including chloramphenicol. Identification of C. neoformans was performed on the basis of melanin synthesis on bird seed agar, presence of a capsule on India ink preparation, urease production on urea agar medium, and ability to grow at 37 °C. An assimilation test was also used to confirm C. neoformans. Results: Of the 65 samples, 22 (34%) were positive for C. neoformans. The highest frequency was observed in droppings from site 7 (86%). The lowest frequency was obtained on samples from sites 2, 3, and 4 (17%). Conclusion: Our study showed the presence of C. neoformans in urban environmental sources at places with a large population in Ahwaz. © TÜBİTAK.