ABSTRACT
During the COVID-19 pandemic, fungal infections, especially pulmonary aspergillosis, mucormycosis, and invasive candidiasis, have emerged as a significant health concern. Beyond Candida albicans, the most common cause of invasive candidiasis, other rare ascomycetous yeast species have been described in tertiary care units, potentially posing a broader health threat. We have isolated, from September 2020 to June 2021, nine Diutina catenulata strains from urine samples of six patients. This was intriguing as this fungus had not been previously identified in our institution, nor after June 2021. Therefore, we decided to outline the clinical features of the patients with this rare pathogen, to describe phenotypic characteristics, including antifungal susceptibility profiles, of this yeast species and to identify the genetic makeup through whole-genome sequencing analysis to evaluate if this was a cluster of genetically similar D. catenulata isolates in our institution. The strains were identified through MALDI-TOF MS analyses and Sanger sequencing of two rDNA regions. All patients yielding D. catenulata from urine samples needed ventilator support and used urinary catheters during hospitalization for treatment of COVID-19. None of them had received COVID-19 vaccines. Morphological and biochemical profiles of the nine strains were largely consistent, although fluconazole susceptibility varied, ranging from 4 to 32 µg/mL. Phylogenomic analysis revealed minimal genetic variation among the isolates, with low intrapopulation variation, supported by the identification of only 84 SNPs across all strains. Therefore, we propose that the yeast strains isolated were part of a cluster of D. catenulata funguria in the context of COVID-19.
Subject(s)
Antifungal Agents , COVID-19 , SARS-CoV-2 , Tertiary Care Centers , Humans , COVID-19/microbiology , COVID-19/epidemiology , Tertiary Care Centers/statistics & numerical data , Brazil/epidemiology , Male , Female , Middle Aged , Antifungal Agents/therapeutic use , Antifungal Agents/pharmacology , SARS-CoV-2/genetics , SARS-CoV-2/drug effects , Aged , Adult , Phylogeny , Microbial Sensitivity Tests , Saccharomycetales/genetics , Saccharomycetales/isolation & purification , Saccharomycetales/classification , Whole Genome SequencingABSTRACT
We aimed to develop and validate a Loop-mediated Isothermal Amplification (LAMP) assay to Sporothrix brasiliensis. LAMP reaction was developed using six primers designed based on calmodulin gene. In the LAMP reaction, we tested twenty isolates of S. brasiliensis from animals and humans, along with ten tissue samples extracted from the left footpad of mice that had been experimentally infected with S. brasiliensis. In addition, it included DNA samples from various other fungal species for specificity evaluation. All S. brasiliensis isolates yielded positive results in the LAMP, and the limit of DNA detection was 1 ng/µL. All murine samples were positive in the test while DNA from other fungal species were all negative, resulting in 100% of sensitivity and specificity of primers. LAMP diagnosis technique is a promising alternative to sporotrichosis diagnosis, in a simple and cost-effective way. Further studies are warranted to validate this technique using animal model samples obtained from both humans and animals.
Subject(s)
DNA Primers , Molecular Diagnostic Techniques , Nucleic Acid Amplification Techniques , Sensitivity and Specificity , Sporothrix , Sporotrichosis , Sporothrix/genetics , Sporothrix/isolation & purification , Sporothrix/classification , Sporotrichosis/diagnosis , Sporotrichosis/microbiology , Sporotrichosis/veterinary , Animals , Nucleic Acid Amplification Techniques/methods , Molecular Diagnostic Techniques/methods , Mice , Humans , DNA Primers/genetics , Disease Models, Animal , Calmodulin/geneticsABSTRACT
Coccidioidomycosis, listed as a priority mycosis by the WHO, is endemic in the United States but often overlooked in Central and South America. Employing a multi-institutional approach, we investigate how disease characteristics, pathogen genetic variation, and environmental factors impact coccidioidomycosis epidemiology and outcomes in South America. We identified 292 cases (1978-2021) and 42 outbreaks in Piauí and Maranhão states, Brazil, the largest series outside the US/Mexico epidemic zone. The male-to-female ratio was 57.4:1 and the most common activity was armadillo hunting (91.1%) 4 to 30 days before symptom onset. Most patients (92.8%) exhibited typical acute pulmonary disease, with cough (93%), fever (90%), and chest pain (77%) as predominant symptoms. The case fatality rate was 8%. Our negative binomial regression model indicates that reduced precipitation levels in the current (p = 0.015) and preceding year (p = 0.001) predict heightened incidence. Unlike other hotspots, acidic soil characterizes this region. Brazilian strains differ genomically from other C. posadasii lineages. Northeastern Brazil presents a distinctive coccidioidomycosis profile, with armadillo hunters facing elevated risks. Low annual rainfall emerges as a key factor in increasing cases. A unique C. posadasii lineage in Brazil suggests potential differences in environmental, virulence, and/or pathogenesis traits compared to other Coccidioides genotypes.
Subject(s)
Coccidioidomycosis , Humans , Female , Male , Animals , Brazil/epidemiology , Coccidioidomycosis/epidemiology , Armadillos , Genomics , GenotypeABSTRACT
ABSTRACTHistoplasmosis is an endemic mycosis in North America frequently reported along the Ohio and Mississippi River Valleys, although autochthonous cases occur in non-endemic areas. In the United States, the disease is provoked by two genetically distinct clades of Histoplasma capsulatum sensu lato, Histoplasma mississippiense (Nam1) and H. ohiense (Nam2). To bridge the molecular epidemiological gap, we genotyped 93 Histoplasma isolates (62 novel genomes) including clinical, environmental, and veterinarian samples from a broader geographical range by whole-genome sequencing, followed by evolutionary and species niche modelling analyses. We show that histoplasmosis is caused by two major lineages, H. ohiense and H. mississippiense; with sporadic cases caused by H. suramericanum in California and Texas. While H. ohiense is prevalent in eastern states, H. mississipiense was found to be prevalent in the central and western portions of the United States, but also geographically overlapping in some areas suggesting that these species might co-occur. Species Niche Modelling revealed that H. ohiense thrives in places with warmer and drier conditions, while H. mississippiense is endemic to areas with cooler temperatures and more precipitation. In addition, we predicted multiple areas of secondary contact zones where the two species co-occur, potentially facilitating gene exchange and hybridization. This study provides the most comprehensive understanding of the genomic epidemiology of histoplasmosis in the USA and lays a blueprint for the study of invasive fungal diseases.
Subject(s)
Histoplasmosis , Histoplasmosis/epidemiology , Histoplasma/genetics , Genotype , Genomics , TexasABSTRACT
Sporotrichosis has been expanding throughout the Brazilian territory in recent years. New outbreaks have emerged, and consequently, the sporotrichosis agents, mainly Sporothrix brasiliensis, should remain in the environment somehow. Therefore, the aim of this study was to investigate the presence of Sporothrix spp. in the environment from an area of ââthe Rio de Janeiro state, Brazil, with recurrent cases of human and animal sporotrichosis. Abandoned demolition timber wood samples were collected in the garden of a house where the cases of human and feline sporotrichosis have occurred in the last 10 years. The environmental survey revealed a Sporothrix spp. colony from the serial dilution cultures of one abandoned demolition wood sample. In addition, a fungal strain isolated from a cat with skin lesions that lived in the house was also included in the study. The species-specific PCR, and calmodulin partial sequencing identified the environmental and cat isolates as S. brasiliensis. Furthermore, the phylogenetic analysis performed with the partial sequences of internal transcribed spacer region and constitutive genes (calmodulin, ß-tubulin, and chitin synthase) showed high similarity between environmental and cat isolates from the same geographic region. Moreover, the antifungal susceptibility test revealed that the minimal inhibitory concentration of itraconazole from the environment isolate was lower than the cat isolate, while amphotericin B and terbinafine were similar. Our results show that S. brasiliensis is able to maintain itself in the environmental material for years. With this, we corroborate that the eco-epidemiology of sporotrichosis is not well understood, and despite the major occurrence of S. brasiliensis in Brazil, it is rarely isolated from the environment.
Subject(s)
Sporothrix , Sporotrichosis , Animals , Brazil/epidemiology , Calmodulin/genetics , Cats , Phylogeny , Sporothrix/genetics , Sporotrichosis/epidemiology , Sporotrichosis/microbiology , Sporotrichosis/veterinaryABSTRACT
Cryptococcus spp. are human pathogens that cause 181,000 deaths per year. In this work, we systematically investigated the virulence attributes of Cryptococcus spp. clinical isolates and correlated them with patient data to better understand cryptococcosis. We collected 66 C. neoformans and 19 C. gattii clinical isolates and analyzed multiple virulence phenotypes and host-pathogen interaction outcomes. C. neoformans isolates tended to melanize faster and more intensely and produce thinner capsules in comparison with C. gattii. We also observed correlations that match previous studies, such as that between secreted laccase and disease outcome in patients. We measured Cryptococcus colony melanization kinetics, which followed a sigmoidal curve for most isolates, and showed that faster melanization correlated positively with LC3-associated phagocytosis evasion, virulence in Galleria mellonella and worse prognosis in humans. These results suggest that the speed of melanization, more than the total amount of melanin Cryptococcus spp. produces, is crucial for virulence.
ABSTRACT
INTRODUCTION: Paracoccidioidomycosis (PCM) is caused by several species of the Paracoccidioides genus which can be differentiated by interspecific genetic variations, morphology and geographic distribution. Intraspecific variability correlation with clinical and epidemiological aspects of these species still remains unclear. This study aimed to sequence the loci GP43, exon 2 and ARF of 23 clinical isolates of Paracoccidioides spp. from patients in the Southeast Region of Brazil. METHODOLOGY AND MAIN FINDINGS: GenBank was used to compare the present (23) with previous described sequences (151) that included ARF and GP43. It was identified a high polymorphism rate among the 23 isolates in comparison to the other 151. Among the isolates, 22 (95.66%) were S1/P. brasiliensis and 1 (4.34%) was identified as PS2/P. americana. A total of 45 haplotypes were found as follows: 19 from S1/P. brasiliensis (13 from the present study), 15 from P. lutzii, 6 from PS2/P. americana (1 from the present study), 3 from PS3/P. restrepiensis and 2 from PS4/P. venezuelensis. Moreover, exclusive haplotypes according to clinical origin and geographical area were found. S1/P. brasiliensis (HD = 0.655 and K = 4.613) and P. lutzii (HD = 0.649 and K = 2.906) presented the highest rate of polymorphism among all species, from which 12 isolates of the present study were clustered within S1b/P. brasiliensis. The GP43 locus showed a higher variability and was found to be the main reason for the species differentiation. CONCLUSIONS: The results herein decribed show a high intraspecific genetic variability among S1/P. brasiliensis isolates and confirm the predominance of this species in the Southeast region of Brazil. The finding of exclusive haplotypes according to clinical origin and geographical area would suggest correlation between the molecular profile with the clinical form and geographic origin of patients with PCM.
Subject(s)
Paracoccidioides/genetics , Paracoccidioidomycosis/microbiology , Adolescent , Adult , Brazil/epidemiology , Child , Child, Preschool , Female , Genetic Variation , Hospitals, Teaching/statistics & numerical data , Humans , Infant , Male , Middle Aged , Molecular Epidemiology , Paracoccidioides/classification , Paracoccidioides/isolation & purification , Paracoccidioidomycosis/epidemiology , Phylogeny , Young AdultABSTRACT
BACKGROUND: Paracoccidioidomycosis (PCM) is a systemic mycosis endemic to Latin America. Etiological agents are Paracoccidioides species that diverge phylogenetically throughout South America. OBJECTIVES: This study aimed to document the epidemiology of PCM in Venezuela. METHODS: We have performed a retrospective cross-sectional descriptive study in 31,081 clinical records of patients from two reference centres during 65 years (1954-2019). FINDINGS: PCM diagnosis was confirmed in 745 patients. Chronic PCM was the most prevalent form (90.06% cases); 80.67% were male and the most affected age range was 41-60. Farming and construction were the most prevalent occupation and Miranda State had a higher prevalence. Lung and skin were the most affected organs, followed by oral manifestations. Direct examination, culture and serology showed a high sensibility, and no statistical difference was observed among the diagnostic tools. Out of 17 Paracoccidioides isolates genotyped from Venezuela, one was typed as Paracoccidioides americana and 16 as Paracoccidioides venezuelensis. MAIN CONCLUSIONS: Clinical manifestations observed, information about the epidemiology and molecular profile is essential not only for diagnosis but also for understanding therapeutic responses to mycotic drugs and prognosis. Therefore, it is necessary to sequence all positive isolated strains in order to confirm the dominance of P. venezuelensis in Venezuela.
Subject(s)
Paracoccidioides , Paracoccidioidomycosis , Cross-Sectional Studies , Humans , Male , Paracoccidioides/genetics , Paracoccidioidomycosis/diagnosis , Paracoccidioidomycosis/epidemiology , Retrospective Studies , Venezuela/epidemiologyABSTRACT
Soil is the principal habitat and reservoir of fungi that act on ecological processes vital for life on Earth. Understanding soil fungal community structures and the patterns of species distribution is crucial, considering climatic change and the increasing anthropic impacts affecting nature. We evaluated the soil fungal diversity in southeastern Brazil, in a transitional region that harbors patches of distinct biomes and ecoregions. The samples originated from eight habitats, namely: semi-deciduous forest, Brazilian savanna, pasture, coffee and sugarcane plantation, abandoned buildings, owls' and armadillos' burrows. Forty-four soil samples collected in two periods were evaluated by metagenomic approaches, focusing on the high-throughput DNA sequencing of the ITS2 rDNA region in the Illumina platform. Normalized difference vegetation index (NDVI) was used for vegetation cover analysis. NDVI values showed a linear relationship with both diversity and richness, reinforcing the importance of a healthy vegetation for the establishment of a diverse and complex fungal community. The owls' burrows presented a peculiar fungal composition, including high rates of Onygenales, commonly associated with keratinous animal wastes, and Trichosporonales, a group of basidiomycetous yeasts. Levels of organic matter and copper influenced all guild communities analyzed, supporting them as important drivers in shaping the fungal communities' structures.
ABSTRACT
BACKGROUND: Histoplasmosis is acquired by inhalation of spores of the dimorphic fungus Histoplasma spp. Although this pathogen is distributed worldwide, it is more prevalent in the Americas. However, the real burden of histoplasmosis remains undefined in many endemic regions. METHODOLOGY: We conducted a series of 61 autopsies to individuals who died in a hospital in the Brazilian Amazon focused on infectious diseases. We performed a detailed histological and microbiological evaluation with genetic characterization of Histoplasma strains with the aim to evaluate the contribution of histoplasmosis to morbidity and mortality. Additionally, we assessed the clinicopathological correlation. PRINCIPAL FINDINGS: Evidence of Histoplasma infection was detected in 21 patients (34%). Eight cases were disseminated infections, all of them occurred in HIV-positive patients. Six cases were localized histoplasmosis, limited to the lungs. In seven patients Histoplasma DNA was detected by PCR in patients with no histological lesions. Histoplasma infection was detected in 38% of HIV-positive patients and was a major contributor to death in 22% of them. Lungs, liver and spleen were affected in all cases of disseminated histoplasmosis. Phylogenetic analysis of the strains suggested a high diversity of Histoplasma species circulating in the Brazilian Amazon. Histoplasmosis was clinically missed in 75% of the disseminated infections. CONCLUSIONS: The high incidence of histoplasmosis, the low index of clinical suspicion, and the severity of the disseminated disease highlight the need of proactively implementing sensitive routine screening methods for this pathogen in endemic areas. Antifungal prophylaxis against Histoplasma should be encouraged in the severely immunocompromised HIV patients in these areas. In conclusion, substantial mortality is associated with disseminated histoplasmosis among HIV-positive patients in the Brazilian Amazon.
Subject(s)
AIDS-Related Opportunistic Infections/microbiology , Histoplasma/classification , Histoplasma/genetics , Histoplasmosis/microbiology , AIDS-Related Opportunistic Infections/mortality , Adolescent , Adult , Aged , Aged, 80 and over , Autopsy , Brazil/epidemiology , Female , Histoplasmosis/mortality , Histoplasmosis/pathology , Humans , Male , Middle Aged , Phylogeny , Prevalence , Young AdultABSTRACT
Paracoccidioidomycosis is an endemic fungal disease to Latin America caused by at least five species-level genotypes of Paracoccidioides, named P. lutzii, P. brasiliensis (S1a and S1b populations), P. americana, P. restrepiensis, and P. venezuelensis. In this manuscript, we report on Paracoccidioides sp. sampling efforts in armadillos from two different areas in Brazil. We sequenced the genomes of seven Paracoccidioides isolates and used phylogenomics and populations genetics for genotyping. We found that P. brasiliensis and P. lutzii are both present in the Amazon region. Additionally, we identified two Paracoccidioides isolates that seem to be the result of admixture between divergent populations within P. brasiliensis sensu stricto. Both of these isolates were recovered from armadillos in a P. lutzii endemic area in Midwestern Brazil. Additionally, two isolates from human patients also show evidence of resulting from admixture. Our results suggest that the populations of P. brasiliensis sensu stricto exchange genes in nature. More generally, they suggest that population structure and admixture within species is an important source of variation for pathogenic fungi.
ABSTRACT
BACKGROUND Paracoccidioidomycosis (PCM) is a systemic mycosis endemic to Latin America. Etiological agents are Paracoccidioides species that diverge phylogenetically throughout South America. OBJECTIVES This study aimed to document the epidemiology of PCM in Venezuela. METHODS We have performed a retrospective cross-sectional descriptive study in 31,081 clinical records of patients from two reference centres during 65 years (1954-2019). FINDINGS PCM diagnosis was confirmed in 745 patients. Chronic PCM was the most prevalent form (90.06% cases); 80.67% were male and the most affected age range was 41-60. Farming and construction were the most prevalent occupation and Miranda State had a higher prevalence. Lung and skin were the most affected organs, followed by oral manifestations. Direct examination, culture and serology showed a high sensibility, and no statistical difference was observed among the diagnostic tools. Out of 17 Paracoccidioides isolates genotyped from Venezuela, one was typed as Paracoccidioides americana and 16 as Paracoccidioides venezuelensis. MAIN CONCLUSIONS Clinical manifestations observed, information about the epidemiology and molecular profile is essential not only for diagnosis but also for understanding therapeutic responses to mycotic drugs and prognosis. Therefore, it is necessary to sequence all positive isolated strains in order to confirm the dominance of P. venezuelensis in Venezuela.
Subject(s)
Humans , Male , Paracoccidioides/genetics , Paracoccidioidomycosis/genetics , Paracoccidioidomycosis/epidemiology , Venezuela/epidemiology , Cross-Sectional Studies , Retrospective StudiesABSTRACT
Sporotrichosis is a subcutaneous infection caused by fungi from the genus Sporothrix. It is transmitted by inoculation of infective particles found in plant-contaminated material or diseased animals, characterizing the classic sapronotic and emerging zoonotic transmission, respectively. Since 1998, southeastern Brazil has experienced a zoonotic sporotrichosis epidemic caused by S. brasiliensis, centred in the state of Rio de Janeiro. Our observation of feline sporotrichosis cases in Brasília (Midwestern Brazil), around 900â km away from Rio de Janeiro, led us to question whether the epidemic caused by S. brasiliensis has spread from the epicentre in Rio de Janeiro, emerged independently in the two locations, or if the disease has been present and unrecognized in Midwestern Brazil. A retrospective analysis of 91 human and 4 animal cases from Brasília, ranging from 1993 to 2018, suggests the occurrence of both sapronotic and zoonotic transmission. Molecular typing of the calmodulin locus identified S. schenckii as the agent in two animals and all seven human patients from which we were able to recover clinical isolates. In two other animals, the disease was caused by S. brasiliensis. Whole-genome sequence typing of seven Sporothrix spp. strains from Brasília and Rio de Janeiro suggests that S. brasiliensis isolates from Brasília are genetically distinct from those obtained at the epicentre of the outbreak in Rio de Janeiro, both in phylogenomic and population genomic analyses. The two S. brasiliensis populations seem to have separated between 2.2 and 3.1 million years ago, indicating independent outbreaks or that the zoonotic S. brasiliensis outbreak might have started earlier and be more widespread in South America than previously recognized.
Subject(s)
Calmodulin/genetics , Sporothrix/classification , Sporotrichosis/epidemiology , Whole Genome Sequencing/methods , Zoonoses/microbiology , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Brazil/epidemiology , Cats , Child , Child, Preschool , Cross-Sectional Studies , Dogs , Evolution, Molecular , Female , Genome, Fungal , High-Throughput Nucleotide Sequencing , Humans , Infant , Male , Middle Aged , Molecular Typing , Phylogeny , Sporothrix/genetics , Sporothrix/isolation & purification , Sporotrichosis/microbiology , Young Adult , Zoonoses/epidemiologyABSTRACT
Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis widely reported in the Gran Chaco ecosystem. The disease is caused by different species from the genus Paracoccidioides, which are all endemic to South and Central America. Here, we sequenced and analyzed 31 isolates of Paracoccidioides across South America, with particular focus on isolates from Argentina and Paraguay. The de novo sequenced isolates were compared with publicly available genomes. Phylogenetics and population genomics revealed that PCM in Argentina and Paraguay is caused by three distinct Paracoccidioides genotypes, P. brasiliensis (S1a and S1b) and P. restrepiensis (PS3). P. brasiliensis S1a isolates from Argentina are frequently associated with chronic forms of the disease. Our results suggest the existence of extensive molecular polymorphism among Paracoccidioides species, and provide a framework to begin to dissect the connection between genotypic differences in the pathogen and the clinical outcomes of the disease.
Subject(s)
Genetic Variation/genetics , Genomics , Paracoccidioides/genetics , Paracoccidioidomycosis/genetics , Argentina/epidemiology , Ecosystem , Genetics, Population , Genome, Fungal/genetics , Genotype , Humans , Paracoccidioides/classification , Paracoccidioides/pathogenicity , Paracoccidioidomycosis/classification , Paracoccidioidomycosis/epidemiology , Paracoccidioidomycosis/microbiology , Paraguay/epidemiology , PhylogenyABSTRACT
Filamentous fungi are well known for producing secondary metabolites applied in various industrial segments. Among these, lovastatin and itaconic acid, produced by Aspergillus terreus, have applications in the pharmaceutical and chemical industries. Lovastatin is primarily used for the control of hypercholesterolemia, while itaconic acid is a building block for the production of synthetic fibers, coating adhesives, among others. In this study, for the first time, 35 strains of Aspergillus sp. from four Brazilian culture collections were evaluated for lovastatin and itaconic acid production and compared to a reference strain, ATCC 20542. From an initial screening, the strains ATCC 20542, URM 224, URM1876, URM 5061, URM 5254, URM 5256, URM 5650, and URM 5961 were selected for genomic comparison. Among tested strains, the locus corresponding to the lovastatin genomic cluster was assembled, showing that all genes essential for lovastatin biosynthesis were present in producing URM 5961 and URM 5650 strains, with 100% and 98.5% similarity to ATCC 20542, respectively. However, in the no producing URM 1876, URM 224, URM 5254, URM 5061, and URM 5256 strains, this cluster was either fragmented or missing. Among the 35 strains evaluated for itaconic acid production in this study, only three strains had titers above 0.5 g/L, 16 strains had production below 0.5 g/L, and the remaining 18 strains had no production, with the highest production of itaconic acid observed in the URM 5254 strain with 2.2 g/L. The essential genes for itaconic acid production, mttA, cadA msfA were also mapped, where all three genes linked to itaconic acid production were found in a single contig in the assembly of each strain. In contrast to lovastatin loci, there is no correlation between the level of itaconic acid production and genetic polymorphisms in the genes associated with its biosynthesis.
Subject(s)
Aspergillus , Lovastatin , Succinates , Aspergillus/genetics , Aspergillus/metabolism , Biodiversity , Brazil , Genes, Fungal , Genetic Variation , Genome, Fungal , Lovastatin/biosynthesis , Lovastatin/genetics , Phylogeny , Succinates/metabolismABSTRACT
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.
Subject(s)
Amoeba/physiology , Host-Pathogen Interactions/physiology , Paracoccidioides/physiology , Soil Microbiology , Acanthamoeba castellanii/physiology , Amoeba/cytology , Amoeba/microbiology , Animals , Armadillos , Ciliophora , Coculture Techniques , Disease Models, Animal , Fungi , Macrophages/microbiology , Male , Mice , Mice, Inbred BALB C , Nematoda , Paracoccidioides/pathogenicity , Paracoccidioidomycosis/microbiology , Phagocytosis , Soil , Virulence , Virulence Factors/physiologyABSTRACT
Histoplasmosis is a worldwide-distributed deep mycosis that affects healthy and immunocompromised hosts. Severe and disseminated disease is especially common in HIV-infected patients. At least 11 phylogenetic species are recognized and the majority of diversity is found in Latin America. The northeastern region of Brazil has one of the highest HIV/AIDS prevalence in Latin America and Ceará State has one of the highest death rates due to histoplasmosis in the world, where the mortality rate varies between 33-42%. The phylogenetic distribution and population genetic structure of 51 clinical isolates from Northeast Brazil was studied. For that morphological characteristics, exoantigens profile, and fungal mating types were evaluated. The genotypes were deduced by a MSLT in order to define local population structure of this fungal pathogen. In addition, the relationships of H. capsulatum genotypes with clinically relevant phenotypes and clinical aspects were investigated. The results suggest two cryptic species, herein named population Northeast BR1 and population Northeast BR2. These populations are recombining, exhibit a high level of haplotype diversity, and contain different ratios of mating types MAT1-1 and MAT1-2. However, differences in phenotypes or clinical aspects were not observed within these new cryptic species. A HIV patient can be co-infected by two or more genotypes from Northeast BR1 and/or Northeast BR2, which may have significant impact on disease progression due to the impaired immune response. We hypothesize that co-infections could be the result of multiple exposure events and may indicate higher risk of disseminated histoplasmosis, especially in HIV infected patients.
Subject(s)
HIV Infections/genetics , Histoplasma/genetics , Histoplasmosis/genetics , Phylogeny , Adult , Brazil/epidemiology , Female , Genetic Variation/genetics , Genotype , HIV/genetics , HIV/pathogenicity , HIV Infections/microbiology , HIV Infections/pathology , HIV Infections/virology , Haplotypes/genetics , Histoplasma/pathogenicity , Histoplasmosis/microbiology , Histoplasmosis/pathology , Histoplasmosis/virology , Humans , Male , Middle Aged , Young AdultABSTRACT
Coccidioides fungi are widely distributed in the American continents, with an expanding western range documented by a recently discovered cryptic population of Coccidioides immitis in Washington State. The assembled and annotated reference genome sequence of the soil-derived C. immitis strain WA_211 will support population and functional genomics studies.
ABSTRACT
INTRODUCTION: The agents of paracoccidioidomycosis, historically identified as Paracoccidioides brasiliensis, are in fact different phylogenetic species. This study aims to evaluate associations between Paracoccidioides phylogenetic species and corresponding clinical data. METHODS: Paracoccidioides strains from INI/Fiocruz patients (1998-2016) were recovered. Socio-demographic, epidemiological, clinical, serological, therapeutic and prognostic data of the patients were collected to evaluate possible associations of these variables with the fungal species identified through partial sequencing of the ADP-ribosylation factor (arf) and the 43-kDa-glycoprotein (gp43) genes. RESULTS: Fifty-four fungal strains were recovered from 47 patients, most (72.3%) infected in Rio de Janeiro state, Brazil. Forty-one cases were caused by Paracoccidioides brasiliensis and six by Paracoccidioides americana (former PS2). P. brasiliensis was responsible for severe lymph abdominal forms, whereas patients infected with P. americana presented a high rate of adrenal involvement. However, no statistically significant associations were found for all variables studied. P. americana presented 100% reactivity to immunodiffusion, even when tested against antigens from other species, while negative results were observed in 9 (20%) cases caused by P. brasiliensis, despite being tested against a homologous antigen. CONCLUSIONS: P. brasiliensis and P. americana are sympatric and share similar clinical features and habitat, where they may compete for similar hosts.
Subject(s)
Genetic Background , Paracoccidioides/classification , Paracoccidioides/genetics , Paracoccidioidomycosis/microbiology , Paracoccidioidomycosis/pathology , Sympatry , ADP-Ribosylation Factors/genetics , Adult , Antigens, Fungal/genetics , Brazil , Female , Fungal Proteins/genetics , Glycoproteins/genetics , Humans , Male , Middle Aged , Paracoccidioides/isolation & purification , Sequence Analysis, DNAABSTRACT
Paracoccidioidomycosis is a systemic fungal disease associated with agricultural activities. Its incidence and prevalence are underestimated because of the lack of reporting in several Brazilian states. If paracoccidiodomycosis is not diagnosed and treated early and adequately, endemic fungal infection may result in serious sequelae. In addition to the Paracoccidioides brasiliensis (P. brasiliensis) complex, the appearance of a new species, Paracoccidioides lutzii (P. lutzii), in Rondônia state, where the disease has reached epidemic levels, and in the country's Midwest region and Pará state, are challenges to diagnosis and to the urgent availability of antigens that are reactive with patients' sera. These guidelines aim to update the first Brazilian consensus on paracoccidioidomycosis by providing evidence-based recommendations for bedside patient management. The guidelines provide data on etiology, epidemiology, immunopathogenesis, diagnosis, treatment and sequelae, with emphasis on diagnosis and treatment, as well as current recommendations and challenges in this field of knowledge.
A paracoccidioidomicose (PCM) é uma micose sistêmica, relacionada às atividades agrícolas, com incidência e prevalência subestimadas, pela ausência de notificação em várias Unidades da Federação (UFs). A evolução insidiosa do quadro clínico pode ter como consequência sequelas graves se o diagnóstico e o tratamento não forem instituídos precoce e adequadamente. Ao lado do complexo Paracoccidioides brasiliensis (P. brasiliensis), a descrição de nova espécie, Paracoccidioides lutzii (P. lutzii), em Rondônia, onde a doença alcançou níveis epidêmicos, bem como na região Centro-Oeste e no Pará, constituem-se em desafios para a instituição do diagnóstico e a urgente disponibilização de antígenos que tenham reatividade com os soros dos pacientes. Este consenso visa atualizar o primeiro consenso brasileiro em PCM, estabelecendo recomendações para o manejo clínico do paciente, com base nas evidências conhecidas. São apresentados dados de etiologia, epidemiologia, imunopatogenia, diagnóstico, terapêutica e sequelas, enfatizando-se o diagnóstico e a terapêutica, bem como recomendações e desafios atuais nessa área do conhecimento.
La paracoccidioidomicosis es una micosis sistémica, relacionada con las actividades agrícolas, con incidencia y prevalencia subestimadas por la ausencia de notificación en varios estados. La evolución insidiosa del cuadro clínico puede tener como consecuencia secuelas graves si el diagnóstico y el tratamiento no se establecen precoz y adecuadamente. Al lado del complejo Paracoccidioides brasiliensis (P. brasiliensis), la descripción de nueva especie, Paracoccidioides lutzii (P. lutzii) en Rondonia, donde la enfermedad alcanzó niveles epidémicos, y en la región Centro Oeste y en Pará, se constituyen en desafíos para la institución del diagnóstico y la urgente puesta a disposición de antígenos que tengan reactividad con los sueros de los pacientes. El presente consenso tiene por objeto actualizar el primer consenso brasileño en paracoccidioidomicosis, estableciendo recomendaciones para el manejo del paciente al borde del lecho, con base en las evidencias conocidas. Se presentan datos de etiología, epidemiología, inmunopatogenia, diagnóstico, terapéutica y secuelas, enfatizando el diagnóstico y terapéutica, así como recomendaciones desafíos y actuales en esta área del conocimiento.