Mating type determination of cryptococcus neoformans isolates obtained from faecal samples of veterinary animals in Botswana

Abstract

Cryptococcus neoformans/gattii species complex cause cryptococcosis, a fatal condition in susceptible humans and animals. This paper aims to find the association of C. neoformans with veterinary excreta, and to carry out a mating type determination of the isolated strains. Two hundred sixty seven veterinary excreta samples from cattle, goats and poultry (chickens) were analysed for the presence of C. neoformans. Morphological and biochemical characteristics were used to identify C. neformans, and mating type-specific PCR amplification was utilized to determine the mating type of the isolates. A total of 72 (26.9%) isolates were found positive for C. neoformans, mostly isolated from cattle (14.9%), followed by poultry (9.4%) and goats (2.6%). However, the isolation rates of the organism from veterinary animals were not statistically significant (p<0.05). Mating type analysis of the 72 positive isolates revealed the presence of MATα, MATα/MATa (hybrids) and MATa in cattle (31.9%, 4.2%, 19.4%)> poultry (19.4%, 2.8%, 12.5%)> and goats (8.3%; 0%, 1.4%), respectively. The frequency of isolation of different mating types was not influenced by the veterinary animals (p<0.05) or sampling location (p<0.05). The results of our study expand the ecological niche of C. neoformans in Botswana and highlight the need to mitigate the dissemination of the pathogen to the population at risk.