The ecological niche that a species can occupy is determined by its resource requirements and the physical conditions necessary for survival. The niche to which an organism is most highly adapted is the realized niche, whereas the complete range of habitats that an organism can occupy represents the fundamental niche. The growth and development of Cryptococcus neoformans and Cryptococcus gattii on pigeon guano were examined to determine whether these two species occupy the same or different ecological niches. C. neoformans is a cosmopolitan pathogenic yeast that infects predominantly immunocompromised individuals, exists in two varieties (grubii [serotype A] and neoformans [serotype D]), and is commonly isolated from pigeon guano worldwide. By contrast, C. gattii often infects immunocompetent individuals and is associated with geographically restricted environments, most notably, eucalyptus trees. Pigeon guano supported the growth of both species, and a brown pigment related to melanin, a key virulence factor, was produced. C. neoformans exhibited prolific mating on pigeon guano, whereas C. gattii did not. The observations that C. neoformans completes the life cycle on pigeon guano but that C. gattii does not indicates that pigeon guano could represent the realized ecological niche for C. neoformans. Because C. gattii grows on pigeon guano but cannot sexually reproduce, pigeon guano represents a fundamental but not a realized niche for C. gattii. Based on these studies, we hypothesize that an ancestral Cryptococcus strain gained the ability to sexually reproduce in pigeon guano and then swept the globe.

https://ec.asm.org/content/eukcell/6/6/949.full.pdf

Cryptococcus neoformans Mates on Pigeon Guano: Implications for the Realized Ecological Niche and Globalization

literature on cave fungi (127 species in 59 genera) but did not include all relevant papers available at that time, and many articles have since been published. Landolt et al. (1992) summarized the few records of slime molds found in caves, but otherwise there has been no comprehensive review of the microf lora in cave habitats. Here we organize data from 225 studies dealing with fungi, yeasts, and slime molds occurring in caves, with 130 of these allowing some exploration of broader patterns of occurrence in relation to the ecology of the cave habitat. Although studies published before 1965 do provide useful records of occurrence, unfortunately many do not report their methods in suff icient detail to allow comparisons with later work. We also identify gaps in information, but most importantly, we note the need for adequately applied and consistently reported methodologies. Our hope is that the review of cave fungi presented here will prove timely and useful to both speleologists and WNS researchers.

/pdf/a-world-review-of-fungi-yeasts-and-slime-molds-in-caves-lg2zvi9pva.pdf

A world review of fungi, yeasts, and slime molds in caves

Environmental isolations have established that Cryptococcus neoformans var. gattii serotype B appears to have a specific ecological association with Eucalyptus camaldulensis. The global distribution of the tree appears to correspond to the epidemiologic distribution of cryptococcosis caused by C. neoformans var. gattii. The epidemiology of cryptococcosis can primarily be explained by exposure to an infective aerosolized inoculum, such as basidiospores released from specific host plants and/or desiccated blastoconidia (yeast cells) disseminated from accumulations of dried pigeon dung. The ecology of C. neoformans still remains largely unresolved, studies on the host-parasite interaction between serotype B and E. camaldulensis are still in progress, and extensive environmental searches are now underway to determine the natural habitats of serotypes A, C and D.

/pdf/the-ecology-of-cryptococcus-neoformans-15j6s1nwqs.pdf

The ecology of Cryptococcus neoformans

Using the method of intraperitoneal inoculation into mice, 11 (13·2%) out of 83 different samples from urban environments in the city of Rio de Janeiro, Brazil, were positive for Cryptococcus neoformans. Isolation of C. neoformans var. neoformans from wood and plant debris within a tree hollow of Syzygium jambolana (jambolana, Java plum) and the finding of C. neoformans var. gattii in bat guano collected in an old house are discussed with reference to our current knowledge on the ecology of C. neoformans.

Isolation of both varieties of Cryptococcus neoformans from saprophytic sources in the city of Rio de Janeiro, Brazil

http://www.museum.lsu.edu/cuervo/pubs_files/Three-striped_Warbler_MPE2012.pdf

Non-monophyly and deep genetic differentiation across low-elevation barriers in a Neotropical montane bird (Basileuterus tristriatus; Aves: Parulidae).

Cryptococcus neoformans was isolated from the organs of 5 Colombian bats. The organism was recovered from the liver and intestine of 3 Carollia perspicillata from Tibu, and from the intestine and spleen of 2 Pteronotus psiolotis from Cartagena. C. neoformans has not been previously recorded from bats. Inoculation into various tissue culture cell-lines showed that L-929 cells gave the best results, and that the use of tissue cultures was a simple, efficient and rapid method for the identification of C. neoformans. All 5 strains of C. neoformans were virulent for CFW mice.

The use of tissue cultures in the identification of Cryptococcus neoformans isolated from Colombian bats.

Twenty three strains of a yeast-like fungus were recovered from the organs of 19 Colombian bats belonging to 4 species (Carollia perspicillata, Desmodus rotundus, Mormo@s megal@hylla and Natalus tumidirostris) from a large cave inhabited by thousands of bats located near the village of San Gil (Santander), Colombia. Soft ticks (Antricola mexicanus), present in large numbers in the cave as well as the guano were also positive for the same fungus. This fungus has not been recovered from bats or guano in other parts of Colombia although more than 5000 bats from 206 localities in 27 departments have been examined. All of the strains were identical both physiologically and morphologically and appeared to be an as yet undescribed species of Candida. It has now been classified as a new Candida and we propose the name Candida chiropterorum. This fungus is very similar physiologically to the Candida ci/errii described by KREGER-VAN ~RIJ (1965) but is quite different in its morphology, as the size and shape of the blastospores are distinct (see Figs. A + B). The buds arise directly from the hyphae, and chlamydospores and large refractory bodies are present. It differs from the majori ty of Candida by its lack of fermentative capacity, and from C. brumptii, C. curvata, C. humicola, C. japonica, C. lipolytica, C. melinii, C. mesenterica, C. mycoderma, C. rugosa and C. zeylonoides by differences in sugar assimilation and from C. scotii in the assimilation of nitrate, and from all described Candida spp. in its morphology. The isolates were investigated using the methods described

A new species of candida from Colombian bats

Species of Sporotricum, Trichophyton and Microsporum from columbian bats.

From the 10th to the 14th of January 1968, 117 species and subspecies of birds, pertaining to 39 families were observed and 529 specimens collected in the Serrania de Macuira of the upper Guajira. One species and two subspecies are recorded for the first time from Colombia, and Dendroica townsendi reported as a new record for South America. Several other birds, seldom collected in Colombia were also found. This is the first detailed report on the avifauna of this highly interesting area.

Birds of the serranía de macuira, guajira peninsula, colombia

A description of the findings in an unusual cave in San Gil (Santander, Colombia), infested with histoplasma.

C. J. Marinkelle

Papers

The use of tissue cultures in the identification of Cryptococcus neoformans isolated from Colombian bats.

A new species of candida from Colombian bats

Species of Sporotricum, Trichophyton and Microsporum from columbian bats.

Birds of the serranía de macuira, guajira peninsula, colombia

Biospeleology of the macaregua cave (colombia)