The molecular types of 443 Brazilian isolates of Cryptococcus neoformans and Cryptococcus gattii were analyzed to determine their geographic distribution within Brazil and their underlying host conditions. The following data, imported from previous epidemiological studies as well as two culture collections, were analyzed for: place of isolation, source (clinical or environmental), host risk factors, species, serotype, mating type, and molecular type. Molecular typing by PCR-fingerprinting using primers for the minisatellite-specific core sequence of the wild-type phage M13 or microsatellites [(GACA)4, (GTG)5], restriction fragment length polymorphism of URA5 gene analysis, and/or amplified fragment length polymorphism (AFLP) identified eight major genotypes: VNI/AFLP1, VNII/AFLP1A, VNIII/AFLP2, and VNIV/AFLP3 for C. neoformans, and VGI/AFLP4, VGII/AFLP6, VGIII/AFLP5, and VGIV/AFLP7 for C. gattii. The most common molecular type found in Brazil was VNI (64%), followed by VGII (21%), VNII (5%), VGIII (4%), VGI and VNIV (3% each), and VNIII (< 1%). Primary cryptococcosis caused by the molecular type VGII (serotype B, MAT alpha) prevails in immunocompetent hosts in the North and Northeast regions, disclosing an endemic regional pattern for this specific molecular type in the Northern Brazil.

Cryptococcus neoformans is an important zoopathogen, and it is one of the most prevalent lethal mycotic agents. Its polysaccharide capsule, synthesized in vivo and in vitro, is a virulence factor, contains predominantly glucuronoxylomannan, and is responsible for the antigenic differentiation of serotypes A, B, C, D, and AD. A total of 467 isolates of C. neoformans obtained from clinical and environmental sources from Brazilian regions were studied serologically by using the Crypto Check Iatron RM 304-K kit. Serotyping of the clinical isolates showed the following prevalences of the serotypes: A (77.95%), followed by B (18.2%), AD (1.3%), D (0.4%), C (0.2%), and untypeable (1.93%). The epidemiology of serotype A in the Brazilian southern and southeastern regions reproduces the picture observed worldwide. In contrast, serotype B was the most frequent agent of cryptococcosis in the northeastern region, occurring nearly equally in male and female healthy hosts. Among the isolates from environmental sources, serotypes A and B were found to occur in the hollows of tropical trees of the genera Cassia, Ficus, and Moquillea. The few isolates from Eucalyptus camaldulensis debris were serotypes A and B and untypeable. Overall, no association with a specific host tree was identified for these serotypes, denoting a distinct ecoepidemiological regional pattern. The one serotype C isolate was recovered from a human immunodeficiency virus-negative host. Serotype AD predominated over serotype D among both clinical and environmental isolates.

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Cryptococcosis is a human fungal infection of significant mortality and morbidity, especially in the meningoencephalitis form. Cryptococcosis is distributed worldwide and its agents, C. neoformans and C. gattii, present eight major molecular types—VNI-VNIV and VGI-VGIV respectively. The primary cryptococcosis caused by molecular type VGII (serotype B, MAT alpha) prevails in immunocompetent patients in the North and Northeast of Brazil, revealing an endemic regional pattern to this molecular type. Since 1999, C. gattii VGII has been involved in an ongoing outbreak in Canada, and is expanding to the Northwest of the United States, two temperate regions. Exposure to propagules dispersed in the environment, related to various organic substrates, mainly decomposing wood in and around dwellings, initiates the infection process. The present study investigated the presence of the agents of cryptococcosis in dust from dwellings in the upper Rio Negro, municipality of Santa Isabel do Rio Negro in Amazonas state. Indoor dust was collected from 51 houses, diluted and plated on bird seed agar. Dark brown colonies were identified phenotypically, and genotypically by URA5 restriction fragment length polymorphism analysis and multilocus sequence typing (MLST). The mating type was identified using pheromone-specific primers. Three of the 51 houses were positive for C. gattii molecular type VGII, MATα and MATa, showing a high prevalence of this agent. MLST studies identified eight subtypes, VGIIb (ST7), VGIIa (ST20), (ST5) and 5 new subtypes unique to the region. For the first time in the state of Amazonas, C. gattii VGII MATα and MATa were isolated from the environment and correlates with endemic cryptococcosis in this state. This is the first description of MLST subtypes on environmental isolates in the Brazilian Amazon, indicating domiciliary dust as a potential source for human infection with different subtypes of C. gattii VGII MATα and MATa.