Vet World   Vol.14   October-2021  Article-23

The first survey of cryptococcal cells in bird droppings across Bloemfontein, South Africa

Background and Aim: Cryptococcal yeast cells are spread across different ecosystems through bird movement and are deposited in bird guano. These cells may be inhaled by humans and lead to cryptococcal pneumonia. In individuals with reduced immune T-cell populations, cells may disseminate to the brain and cause the often-deadly cryptococcal meningitis. In this study, we surveyed cryptococcal cells in bird droppings across the city of Bloemfontein, South Africa.

Materials and Methods: We aseptically collected 120 bird dropping samples from 15 representative city sites. In the laboratory, samples were assessed with regards to location, weighed, and standardized to a mass of 1 g before suspension in 10 mL phosphate buffer saline. Samples were first screened using Calcofluor-white stain as it is a rapid technique for the detection of fungi via binding to cell wall components such as chitin. After this, positive Calcofluor samples were serologically assayed for the cryptococcal antigen (CrAg). To confirm assay data, CrAg positive samples were then cultured on bird seed agar and resulting colonies were assessed using Indian ink.

Results: We determined that 10/15 locations were positive for the CrAg. Pathogenic cells were identified on bird seed agar as brown colonies. When examined using microscopy, brown colony cells exhibited characteristic thick capsules representative of cryptococcal cells.

Conclusion: This is the first proximate analysis showing the ecological distribution of cryptococcal cells in Bloemfontein. This is important as associated infections are acquired from the environment. Similarly, given the threat posed by cryptococcal cells to immunocompromised individuals, local authorities must initiate measures curbing the spread of these cells. Keywords: Bloemfontein, Calcofluor-white stain, cryptococcal antigens, cryptococcal cells, cryptococcal meningitis, cryptococcal pneumonia, South Africa.

Keywords: Bloemfontein, Calcofluor-white stain, cryptococcal antigens, cryptococcal cells, cryptococcal meningitis, cryptococcal pneumonia, South Africa.

How to cite this article: Kankam G, Christians B, Maliehe M, Mjokane N, Ogundeji AO, Folorunso OS, Pohl CH, Sebolai OM (2021) The first survey of cryptococcal cells in bird droppings across Bloemfontein, South Africa, Veterinary World, 14(10): 2739-2744.

Received: 13-05-2021  Accepted: 09-09-2021     Published online: 25-10-2021

Corresponding author: Olihile M. Sebolai   E-mail: sebolaiom@ufs.ac.za

DOI: 10.14202/vetworld.2021.2739-2744

Copyright: Kankam, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.