RESUMO
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.
RESUMO
Inteins (internal proteins) are mobile genetic elements, inserted in housekeeping proteins, with self-splicing properties. Some of these elements have been recently pointed out as modulators of genetic expression or protein function. Herein, we evaluated, in silico, the distribution and phylogenetic patterns of PRP8 intein among 93 fungal strains of the order Onygenales. PRP8 intein(s) are present in most of the species (45/49), mainly as full-length inteins (containing both the Splicing and the Homing Endonuclease domains), and must have transferred vertically in all lineages, since their phylogeny reflects the group phylogeny. While the distribution of PRP8 intein(s) varies among species of Onygenaceae family, being absent in Coccidioides spp. and present as full and mini-intein in other species, they are consistently observed as full-length inteins in all evaluated pathogenic species of the Arthrodermataceae and Ajellomycetaceae families. This conservative and massive PRP8 intein presence in Ajellomycetacean and Arthrodermatecean species reinforces the previous idea that such genetic elements do not decrease the fungal fitness significantly and even might play some role in the host-pathogen relationship, at least in these two fungal groups. We may better position the species Ophidiomyces ophiodiicola (with no intein) in the Onygenaceae family and Onygena corvina (with a full-length intein) as a basal member in the Arthrodermataceae family.
Assuntos
DNA Fúngico/genética , Proteínas Fúngicas/genética , Onygenales/genética , Evolução Molecular , Proteínas Fúngicas/classificação , Inteínas/genética , FilogeniaRESUMO
Paracoccidioides brasiliensis and the related species P. americana, P. restrepiensis, P. venezuelensis, and P. lutzii (Ascomycota, Ajellomycetaceae) are the etiological agents of paracoccidoidoimycosis (PCM), one of the most important systemic mycoses in Latin America. They are dimorphic fungi, with a mycelial life cycle in soil and a yeast phase associated with tissues of mammalian hosts. This study aimed to detect Paracoccidioides spp. in armadillo tissues and associated soil samples in three well-defined geographic areas, including the Alta Floresta, an area not only endemic for PCM in the central region of Brazil but also of probable P. lutzii occurrence, whose ecology and geographic distribution are poorly elucidated. The isolates were genotyped by sequencing ITS-rDNA and the gp43-exon-2 region, and by PCR-RFLP of alpha tubulin (tub1) gene; mycological aspects such as yeast-to-mycelial transition, growth and conidial production in soil extract agar were also evaluated. We confirmed that while armadillos are highly infected by P. brasiliensis, including multiple infections by distinct genotypes or species (P. brasiliensis and P. americana) in the same animal, the same does not hold true for P. lutzii, which in turn seems to present less capacity for mycelial growth and conidial production, when developing in a soil-related condition.
Assuntos
Tatus/microbiologia , Variação Genética , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/veterinária , Microbiologia do Solo , Animais , Antígenos de Fungos/genética , Brasil , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Feminino , Proteínas Fúngicas/genética , Genótipo , Glicoproteínas/genética , Masculino , Técnicas Microbiológicas , Paracoccidioides/classificação , Paracoccidioides/genética , Paracoccidioides/fisiologia , Paracoccidioidomicose/microbiologia , Filogenia , Análise de Sequência de DNA , Tubulina (Proteína)/genéticaRESUMO
Bothrops insularis, known as the golden lancehead snake, has its natural habitat restricted to Queimada Grande Island on the southern coast of Brazil. This culture-dependent study aimed to identify microorganisms obtained from the mouth, eyes, and cloaca of this species. Swabs from 20 snakes were collected for fungal and bacterial isolation. DNA was extracted from all samples, and identification was performed by amplifying the ITS1-5.8S-ITS2 regions and the 16S rDNA gene, respectively. All strains were identified and deposited in the GenBank nucleotide database. MEGA v6.0 software was utilized to construct phylogenetic trees. In total, 100 strains were isolated and characterized, from which 42 fungi were distributed into 23 species and 58 bacteria into 13 species. The genus Fusarium was predominant since 11 strains and probably a new species was isolated from this fungus. Pseudomonas aeruginosa and Enterococcus faecalis were the predominant groups of aerobic bacteria isolated. Phylogenetic analyses between bacterial and fungal sequences suggest a similarity between the microorganisms found on the island and on the continent. These findings may be attributed to anthropic actions resulting from both expeditions to the island and actions of migratory birds, which are the main sources of food for snakes.
Assuntos
Bactérias/isolamento & purificação , Bothrops/microbiologia , Fungos/isolamento & purificação , Micobioma , Animais , Bactérias/classificação , Brasil , DNA Bacteriano/análise , DNA Fúngico/análise , Feminino , Fungos/classificação , Masculino , FilogeniaRESUMO
Dermatophytes constitute a complex group of fungi, comprised of by the genera Trichophyton, Epidermophyton and Microsporum. They have the ability to degrade keratin and cause human and animal infections. Molecular techniques have made their identification faster and more accurate, and allowed important advances in phylogenetic studies. We aim to identify molecularly and to determine the phylogenetic relationships in dermatophyte fungi from Brazil and other Latin American countries, using DNA sequencing of the nuclear ribosome regions ITS1-5.8S-ITS2 and D1/D2. DNA of 45 dermatophytes was extracted and amplified by PCR for identification at the species level by sequencing of those ribosomal regions. The software mega 6.0 was used to establish the phylogenetic relationships via the Maximum Likelihood method. Out of 45 strains, 43 were identified by ITS (95.5%) and 100% by D1/D2 sequencing. Two strains could not be identified by ITS. Phylogenetic analyses separated the genera Trichophyton and Microsporum, which presented an uncertain relationship with Epidermophyton floccosum, depending on the ribosomal marker. Both regions can provide efficient identification of dermatophytes, whereas phylogenetic analysis revealed complex relations among dermatophyte fungi.
Assuntos
Arthrodermataceae/classificação , Arthrodermataceae/isolamento & purificação , Dermatomicoses/microbiologia , Filogenia , Arthrodermataceae/genética , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Humanos , América Latina , Reação em Cadeia da PolimeraseRESUMO
Entre los principales retos de los profesionales de la salud en la actualidad se encuentra desarrollar habilidades en el uso de las Tecnologías de la Información y la Comunicaciones (TIC). Estos retos no son solo aplicables a las modernas técnicas diagnósticas ofrecidas por las grandes transnacionales, que se aprecian en gran medida en las especialidades de perfil investigativo; también revisten una enorme importancia en el campo de la docencia médica. El uso de Internet, los softwares educativos interactivos y simuladores han probado ser herramientas eficaces en el proceso enseñanza aprendizaje tanto en estudios de pregrado como de postgrado. Muchas universidades abogan por la incorporación en sus currículos de habilidades que posibiliten lidiar con el desafío impuesto por esta explosión tecnológica para lo cual deben estar preparadas las universidades médicas del futuro.
The development of skills in the use of information and communication technologies is one of the major challenges facing health professionals nowadays. This challenge is not only relevant to modern diagnostic techniques offered by large corporations, which are widely present in the specialties with research activity; it is also of great importance in the field of medical education. The use of the Internet, interactive educational software and simulators has proven to be an effective tool in the teaching-learning process in both undergraduate and postgraduate levels. Many universities advocate incorporating skills into their curricula that facilitate dealing with the challenge posed by this technological explosion. Medical universities must be prepared for this in the future.