Cryptococcus in Wildlife and Free-Living Mammals

Abstract

Cryptococcosis is typically a sporadic disease that affects a broad range of animal species globally. Disease is a consequence of infection with members of the Cryptococcus neoformans or Cryptococcus gattii species complexes. Although cryptococcosis in many domestic animals has been relatively well-characterized, free-living wildlife animal species are often neglected in the literature outside of occasional case reports. This review summarizes the clinical presentation, pathological findings and potential underlying causes of cryptococcosis in various other animals, including terrestrial wildlife species and marine mammals. The evaluation of the available literature supports the hypothesis that anatomy (particularly of the respiratory tract), behavior and environmental exposures of animals play vital roles in the outcome of host–pathogen–environment interactions resulting in different clinical scenarios. Key examples range from koalas, which exhibit primarily C. gattii species complex disease presumably due to their behavior and environmental exposure to eucalypts, to cetaceans, which show predominantly pulmonary lesions due to their unique respiratory anatomy. Understanding the factors at play in each clinical scenario is a powerful investigative tool, as wildlife species may act as disease sentinels.

Nasopharyngeal cryptococcosis in a cat: interlaboratory variation in cryptococcal antigen assay test results

“…1 – 3 Feline cryptococcosis is caused by Cryptococcus neoformans–Cryptococcus gattii species complex with multiple genotypes and various subtypes. 1 , 2 , 4 In cats, dogs and people, C neoformans and organisms that belong to the C gattii species complex, cause the majority of the disease. 1 , 2 Published studies and case reports of feline cryptococcosis are globally abundant, mainly in the western USA, Canada, Australia and South America.…”

Epidemiological and Clinical Characteristics, Antifungal Susceptibility, and MLST-Based Genetic Analysis of Cryptococcus Isolates in Southern Taiwan in 2013–2020

“…In the last few decades, several widely used molecular methods have been used worldwide to determine the genotypes of clinical, environmental, and veterinary isolates of the members of the C. neoformans and C. gattii species complexes to investigate their geographical distribution, molecular epidemiology, and population genetics [ 19 , 20 , 21 , 22 , 23 ]. Understanding the epidemiological and microbiological characteristics of local Cryptococcus strains and clinical features of CM is essential for the development of efficient diagnosis and treatment strategies.…”

Pharmacological inhibition of titan-like cells formation suggests that accumulation of endogenous free radicals that correlate with mitochondrial changes are required to induce this transition inCryptococcus neoformans

“…Cryptococcus neoformans is a unique fungal pathogen due to its ability to adapt to different environments and infect many different hosts, including mammals (including some aquatic, as dolphins), plants, insects and amoebas (8)(9)(10)(11)(12)(13)(14)(15)(16)(17).…”

“…Cryptococcus neoformans is a unique fungal pathogen due to its ability to adapt to different environments and infect many different hosts, including mammals (including some aquatic, as dolphins), plants, insects and amoebas (8–17). There are several reasons that explain this unique adaptation among fungal pathogens, such its ability to melanize (18, 19) or to survive within phagocytic cells (20–23).…”