Search

Paracoccidioides species have always been surrounded by taxonomic uncertainties. The continuing nomenclatoral muddle was caused in part by the failure of Adolfo Lutz and Jorge Lôbo to name the etiologic agents of human paracoccidioidomycosis and Jorge Lôbo's diseases, respectively. Early in their history, it was postulated that the cultivable species causing systemic infections belonged in the genus Paracoccidioides, whereas the uncultivable species, causing skin disease, were not part of the genus. The taxonomy of these pathogens was further complicated when a similar skin disease with numerous yeast-like cells in infected dolphins was also reported. Due to its phenotypic similarities with that described by Jorge Lôbo in human and its uncultivable nature, it was assumed that the disease in dolphins was caused by the same fungus. Recent molecular and population genetic analysis, however, found the DNA extracted from the uncultivable yeast-like cells affecting dolphins shared common phylogenetic traits with cultivable Paracoccidioides species. The study revealed that the uncultivable pathogens comprised 2 different Paracoccidioides species, now known as P. ceti and P. loboi, correspondingly. To validate P. loboi binomial, a comprehensive historical critical review of Jorge Lôbo etiology was performed. This review showed the proposed binomial P. loboi was previously used, and, thus, a replacement name is introduced, Paracoccidioides lobogeorgii nom. nov. In addition, in this review, several cultivable human Paracoccidioides species are validated, and the generic type species, P. brasiliensis, is neotypified as the original material could not be traced. [ABSTRACT FROM AUTHOR]

Paracoccidioides spp. are thermodimorphic fungi that cause a neglected tropical disease (paracoccidioidomycosis) that is endemic to Latin America. These fungi inhabit the soil, where they live as saprophytes with no need for a mammalian host to complete their life cycle. Despite this, they developed sophisticated virulence attributes allowing them not only to survive in host tissues but also to cause disease. A hypothesis for selective pressures driving the emergence or maintenance of virulence of soil fungi is their interaction with soil predators such as amoebae and helminths. We evaluated the presence of environmental amoeboid predators in soil from armadillo burrows where Paracoccidioides had been previously detected and tested if the interaction of Paracoccidioides with amoebae selects for fungi with increased virulence. Nematodes, ciliates, and amoebae–all potential predators of fungi–grew in cultures from soil samples. Microscopical observation and ITS sequencing identified the amoebae as Acanthamoeba spp, Allovahlkampfia spelaea, and Vermamoeba vermiformis. These three amoebae efficiently ingested, killed and digested Paracoccidioides spp. yeast cells, as did laboratory adapted axenic Acanthamoeba castellanii. Sequential co-cultivation of Paracoccidioides with A. castellanii selected for phenotypical traits related to the survival of the fungus within a natural predator as well as in murine macrophages and in vivo (Galleria mellonella and mice). These changes in virulence were linked to the accumulation of cell wall alpha-glucans, polysaccharides that mask recognition of fungal molecular patterns by host pattern recognition receptors. Altogether, our results indicate that Paracoccidioides inhabits a complex environment with multiple amoeboid predators that can exert selective pressure to guide the evolution of virulence traits. [ABSTRACT FROM AUTHOR]

Mating between different species produces hybrids that are usually asexual and stuck as diploids, but can also lead to the formation of new species. Here, we report the genome sequences of 27 isolates of the pathogenic yeast Candida orthopsilosis. We find that most isolates are diploid hybrids, products of mating between two unknown parental species (A and B) that are 5% divergent in sequence. Isolates vary greatly in the extent of homogenization between A and B, making their genomes a mosaic of highly heterozygous regions interspersed with homozygous regions. Separate phylogenetic analyses of SNPs in the A- and B-derived portions of the genome produces almost identical trees of the isolates with four major clades. However, the presence of two mutually exclusive genotype combinations at the mating type locus, and recombinant mitochondrial genomes diagnostic of inter-clade mating, shows that the species C. orthopsilosis does not have a single evolutionary origin but was created at least four times by separate interspecies hybridizations between parents A and B. Older hybrids have lost more heterozygosity. We also identify two isolates with homozygous genomes derived exclusively from parent A, which are pure non-hybrid strains. The parallel emergence of the same hybrid species from multiple independent hybridization events is common in plant evolution, but is much less documented in pathogenic fungi. [ABSTRACT FROM AUTHOR]

A correction to the article "Environmental Mapping of Paracoccidioides spp. in Brazil Reveals New Clues into Genetic Diversity, Biogeography and Wild Host Association" that was published in the April 29, 2016 issue is presented.

Background: Paracoccidioides brasiliensis and Paracoccidioides lutzii are the etiological agents of Paracoccidioidomycosis (PCM), and are easily isolated from human patients. However, due to human migration and a long latency period, clinical isolates do not reflect the spatial distribution of these pathogens. Molecular detection of P. brasiliensis and P. lutzii from soil, as well as their isolation from wild animals such as armadillos, are important for monitoring their environmental and geographical distribution. This study aimed to detect and, for the first time, evaluate the genetic diversity of P. brasiliensis and P. lutzii for Paracoccidioidomycosis in endemic and non-endemic areas of the environment, by using Nested PCR and in situ hybridization techniques. Methods/Principal Findings: Aerosol (n = 16) and soil (n = 34) samples from armadillo burrows, as well as armadillos (n = 7) were collected in endemic and non-endemic areas of PCM in the Southeastern, Midwestern and Northern regions of Brazil. Both P. brasiliensis and P. lutzii were detected in soil (67.5%) and aerosols (81%) by PCR of Internal Transcribed Spacer (ITS) region (60%), and also by in situ hybridization (83%). Fungal isolation from armadillo tissues was not possible. Sequences from both species of P. brasiliensis and P. lutzii were detected in all regions. In addition, we identified genetic Paracoccidioides variants in soil and aerosol samples which have never been reported before in clinical or armadillo samples, suggesting greater genetic variability in the environment than in vertebrate hosts. Conclusions/Significance: Data may reflect the actual occurrence of Paracoccidioides species in their saprobic habitat, despite their absence/non-detection in seven armadillos evaluated in regions with high prevalence of PCM infection by P. lutzii. These results may indicate a possible ecological difference between P. brasiliensis and P. lutzii concerning their wild hosts. [ABSTRACT FROM AUTHOR]

The article offers information on the incidence of paracoccidioidomycosis (PCM) in Latin America. Topics discussed include the phylogeny of paracoccidioides genus, ecology of paracoccidioides brasiliensis and paracoccidioides lutzii, sexual reproduction of the paracoccidioides species complex, virulence factors associated with dimorphism and host adaptation, and impact of paracoccidioides species complex on clinical and serological aspects of PCM.

Background: Paracoccidioidomycosis is a systemic mycosis caused by Paracoccidioides brasiliensis (species S1, PS2, PS3), and Paracoccidioides lutzii. This work aimed to differentiate species within the genus Paracoccidioides, without applying multilocus sequencing, as well as to obtain knowledge of the possible speciation processes. Methodology/Principal Findings: Single nucleotide polymorphism analysis on GP43, ARF and PRP8 intein genes successfully distinguished isolates into four different species. Morphological evaluation indicated that elongated conidia were observed exclusively in P. lutzii isolates, while all other species (S1, PS2 and PS3) were indistinguishable. To evaluate the biogeographic events that led to the current geographic distribution of Paracoccidioides species and their sister species, Nested Clade and Likelihood Analysis of Geographic Range Evolution (LAGRANGE) analyses were applied. The radiation of Paracoccidioides started in northwest South America, around 11-32 million years ago, as calculated on the basis of ARF substitution rate, in the BEAST program. Vicariance was responsible for the divergence among S1, PS2 and P. lutzii and a recent dispersal generated the PS3 species, restricted to Colombia. Taking into account the ancestral areas revealed by the LAGRANGE analysis and the major geographic distribution of L. loboi in the Amazon basin, a region strongly affected by the Andes uplift and marine incursions in the Cenozoic era, we also speculate about the effect of these geological events on the vicariance between Paracoccidioides and L. loboi. Conclusions/Significance: The use of at least 3 SNPs, but not morphological criteria, as markers allows us to distinguish among the four cryptic species of the genus Paracoccidioides. The work also presents a biogeographic study speculating on how these species might have diverged in South America, thus contributing to elucidating evolutionary aspects of the genus Paracoccidioides. [ABSTRACT FROM AUTHOR]

Background: Identifying clusters of acute paracoccidioidomycosis cases could potentially help in identifying the environmental factors that influence the incidence of this mycosis. However, unlike other endemic mycoses, there are no published reports of clusters of paracoccidioidomycosis. Methodology/Principal Findings: A retrospective cluster detection test was applied to verify if an excess of acute form (AF) paracoccidioidomycosis cases in time and/or space occurred in Botucatu, an endemic area in São Paulo State. The scan-test SaTScan v7.0.3 was set to find clusters for the maximum temporal period of 1 year. The temporal test indicated a significant cluster in 1985 (P<0.005). This cluster comprised 10 cases, although 2.19 were expected for this year in this area. Age and clinical presentation of these cases were typical of AF paracccidioidomycosis. The space-time test confirmed the temporal cluster in 1985 and showed the localities where the risk was higher in that year. The cluster suggests that some particularities took place in the antecedent years in those localities. Analysis of climate variables showed that soil water storage was atypically high in 1982/83 (∼2.11/2.5 SD above mean), and the absolute air humidity in 1984, the year preceding the cluster, was much higher than normal (∼1.6 SD above mean), conditions that may have favored, respectively, antecedent fungal growth in the soil and conidia liberation in 1984, the probable year of exposure. These climatic anomalies in this area was due to the 1982/83 El Niño event, the strongest in the last 50 years. Conclusions/Significance: We describe the first cluster of AF paracoccidioidomycosis, which was potentially linked to a climatic anomaly caused by the 1982/83 El Niño Southern Oscillation. This finding is important because it may help to clarify the conditions that favor Paracoccidioides brasiliensis survival and growth in the environment and that enhance human exposure, thus allowing the development of preventive measures. Author Summary: Paracoccocidioidomycosis is acquired through inhalation of spores released from filamentous forms of Paracoccidioides brasiliensis presumably present in the soil of endemic areas. However, successful isolation of the fungus from these areas has been rare, making it difficult to determine the fungus's ecological niche and the environmental factors that might influence the rate of infection and disease. Identifying clusters of acute paracoccidioidomycosis cases could potentially help at identifying these factors. However, there are no published reports of paracoccidioidomycosis outbreaks. We describe an undetected cluster of acute paracoccidioidomycosis cases diagnosed in 1985 in São Paulo State, Brazil, and investigate its association with climate. We observed that soil water storage was atypically high in 1982/83, and that the absolute air humidity in 1984 was much higher than normal, which may have favored, respectively, antecedent fungal growth in soil and conidia liberation in 1984, the probable year of exposure. This atypically high soil water storage was due to the strongest El Niño event in the area in the last 50 years, which also caused atypically high precipitation in that area. Better knowledge of the conditions that favor the fungus's survival and growth in the environment and that enhance human exposure may facilitate the development of preventive measures. [ABSTRACT FROM AUTHOR]