Social bees harbor conserved gut microbiotas that may have been acquired in a common ancestor of social bees and subsequently codiversified with their hosts. However, most of this knowledge is based ...on studies on the gut microbiotas of honey bees and bumblebees. Much less is known about the gut microbiotas of the third and most diverse group of social bees, the stingless bees. Specifically, the absence of genomic data from their microbiotas presents an important knowledge gap in understanding the evolution and functional diversity of the social bee microbiota. Here, we combined community profiling with culturing and genome sequencing of gut bacteria from six neotropical stingless bee species from Brazil. Phylogenomic analyses show that most stingless bee gut isolates form deep-branching sister clades of core members of the honey bee and bumblebee gut microbiota with conserved functional capabilities, confirming the common ancestry and ecology of their microbiota. However, our bacterial phylogenies were not congruent with those of the host, indicating that the evolution of the social bee gut microbiota was not driven by strict codiversification but included host switches and independent symbiont gain and losses. Finally, as reported for the honey bee and bumblebee microbiotas, we found substantial genomic divergence among strains of stingless bee gut bacteria, suggesting adaptation to different host species and glycan niches. Our study offers first insights into the genomic diversity of the stingless bee microbiota and highlights the need for broader samplings to understand the evolution of the social bee gut microbiota.
Stingless bees are the most diverse group of the corbiculate bees and represent important pollinator species throughout the tropics and subtropics. They harbor specialized microbial communities in their gut that are related to those found in honey bees and bumblebees and that are likely important for bee health. Few bacteria have been cultured from the gut of stingless bees, which has prevented characterization of their genomic diversity and functional potential. Here, we established cultures of major members of the gut microbiotas of six stingless bee species and sequenced their genomes. We found that most stingless bee isolates belong to novel bacterial species distantly related to those found in honey bees and bumblebees and encoding similar functional capabilities. Our study offers a new perspective on the evolution of the social bee gut microbiota and presents a basis for characterizing the symbiotic relationships between gut bacteria and stingless bees.
Dengue virus (DENV) is an arbovirus that belongs to the Flaviviridae family. Studies reveal that peptides secreted by amphibians have many functions, such as antiviral and antimicrobial activities. ...As there is no antiviral drug effective against the DENV, the antiviral activity of a synthetic peptide called HS-1, derived from the secretion of the anuran Hypsiboas semilineatus, has been evaluated. The assays of neutralization in the Vero cells show a complete inhibition of infection of the serotypes 2 and 3. Furthermore, the direct action of peptides on the viral particle can be observed through atomic force microscopy. In vivo tests display 80% protection against the dengue-2 virus due to the presence of HS-1, which reveals its potential as an antiviral against the DENV.
•The use of antimicrobial peptides (AMPs) as antivirals has increased in recent times and has shown promise.•Many molecules have been described as being able to inhibit viral replication, such as, analogs of defensins, dermaseptins, and latarcins.•On account of the lack of a vaccine and treatment against the dengue virus, it has been considered necessary to test antivirals against the dengue virus.•The results are promising against dengue-2 and dengue-3 and the antivirals tested have shown efficiency in both in vitro and in vivo experiments, in which the antiviral appears to act directly on the viral particle, disrupting the lipoprotein envelope.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
ABSTRACT Filamentous fungi have been targeted by bioprospecting studies because they are effective producers of extracellular enzymes that can potentially be used by the bioindustry. In this study, ...we isolated filamentous fungi from the guts of Amazonian aquatic insect larvae to evaluate their cellulolytic activity. We collected 69 larvae of shredder insects of three genera: Phylloicus (Trichoptera: Calamoceratidae), Triplectides (Trichoptera: Leptoceridae) and Stenochironomus (Diptera: Chironomidae) in ten streams from a protected area in the central Brazilian Amazon. Production of mycelia was elaborated in PDA (Potato Dextrose Agar) medium. The isolates were transferred to a synthetic medium with carboxymethyl cellulose, and Congo red was used to determine the enzymatic index. The hydrolysis halo, indicating the production of cellulases, was observed in 175 fungal isolates (70% of the total), of which 25 had an enzymatic index ≥ 2.0 and belonged to seven fungal genera. The fungal taxa Cladosporium, Gliocephalotrichum, Penicillium, Pestalotiopsis, Talaromyces, Trichoderma and Umbelopsis were isolated from guts of Phylloicus, Triplectides and Stenochironomus, which are traditionally used in biotechnological applications. Our results indicate the cellulolytic potential of fungi associated with the guts of aquatic Amazonian insects.
RESUMO Fungos filamentosos tem sido alvo de estudos de bioprospecção devido à sua grande eficiencia em produzir enzimas extracelulares, as quais tem grande potencial para uso em bioindústrias. Neste estudo, fungos filamentosos foram isolados do intestino de larvas de insetos aquáticos da Amazônia, para avaliar sua atividade celulolítica. Foram coletadas 69 larvas de insetos aquáticos fragmentadores de três gêneros: Phylloicus (Trichoptera: Calamoceratidae), Triplectides (Trichoptera: Leptoceridae) e Stenochironomus (Diptera: Chironomidae) em dez igarapés de uma área protegida na Amazônia central brasileira. O crescimento dos fungos isolados foi feito em meio de cultura Ágar Batata Dextrose (BDA). Os isolados fúngicos foram transferidos para o meio sintético com Carboximetil celulose e utilizou-se vermelho Congo para determinar o índice enzimático. O halo de hidrólise, indicando a produção de celulases, foi observado em 175 isolados fúngicos (70% do total), dos quais 25 tiveram um índice enzimático ≥ 2,0 e pertencem a sete gêneros fúngicos. Os táxons fúngicos Cladosporium, Gliocephalotrichum, Penicillium, Pestalotiopsis, Talaromyces, Trichoderma e Umbelopsis foram isolados dos intestinos das larvas de Phylloicus, Triplectides e Stenochironomus e são tradicionalmente utilizados em aplicações biotecnológicas. Os resultados indicam um potencial celulolítco destes fungos associados ao intestino de insetos aquáticos amazônicos.
The multidrug-resistant bacteria have become a serious problem to public health. In this scenery the antimicrobial peptides (AMPs) derived from animals and plants emerge as a novel therapeutic ...modality, substituting or in addition to the conventional antimicrobial. The anurans are one of the richest natural sources of AMPs. In this work several cycles of cDNA cloning of the skin of the Brazilian treefrog Hypsiboas semilineatus led to isolation of a precursor sequence that encodes a new AMP. The sequence comprises a 27 residue signal peptide, followed by an acidic intervening sequence that ends in the mature peptide at the carboxy terminal. The AMP, named Hs-1, has 20 amino acids residues, mostly arranged in an alpha helix and with a molecular weight of 2144.6 Da. The chemically synthesized Hs-1 showed an antimicrobial activity against all Gram-positive bacteria tested, with a range of 11–46 μM, but it did not show any effect against Gram-negative bacteria, which suggest that Hs-1 may have a selective action for Gram-positive bacteria. The effects of Hs-1 on bacterial cells were also demonstrated by transmission electron microscopy. Hs-1 is the first AMP to be described from H. semilineatus.
•We report the identification and characterization of a new AMP named Hs-1.•Hs-1 is the first AMP described for the Brazilian endemic frog Hypsiboas semilineatus.•Hs-1 is selective against Gram-positive bacteria, especially against MRSA.•Hs-1 has a direct antibacterial killing by membrane disruption.•Hs-1 is predominantly structured as an amphipathic alpha helix.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
RESUMO Objetivo: Avaliar a prevalência de Adenovírus como agente etiológico da conjuntivite, em clínica médica oftalmológica especializada, em Viçosa, Minas Gerais, Brasil. Métodos: Amostras da ...secreção conjuntival de 91 pacientes clinicamente diagnosticados com conjuntivite foram submetidos à reação em cadeia da polimerase (PCR), utilizando primers degenerados para a região codificadora do gene da proteína estrutural II. Posteriormente as amostras positivas foram submetidas a sequenciamento e genotipagem. Resultados: A análise dos resultados de PCR revelou prevalência de 36,3% de Adenovírus. Não havendo distinção entre os sexos e com maior prevalência na faixa etária de 26 a 65 anos com 60,60% dos casos positivos. O sequenciamento dos casos positivos por Adenovírus revelaram a presença dos sorotipos 3, 4, 7, 8 e 34 circulante na região. Conclusão: No município de Viçosa, dois em cada cinco casos de conjuntivite são de etiologia adenoviral.
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Previous issue date: 2017-08-29
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Bees, as other social insects, present complex symbiotic interactions with microorganisms, ranging from the individual level (bee) to the different microenvironments of the nest/ colony. These relationships can directly affect the nutritional potential and immunity of bees as well as influence productive processes within the colony, such as food storage and production. Considering that: i) there are few studies on the microbiota of wild bees, in constrast with the available literature of exotic bees Apis mellifera; ii) the knowledge about the symbiotic microorganisms contribute to the understanding of the ecological relationship that guarantee the colony homeostasis and it also provides tools for the prospection of products of biotechnological interest; iii) the fermentative production of bee pollen, the main food of the colony, is a little known process regardless its fundamental importance to the social colonies development; the objective of this work was to elucidate the bacterial communities associated with the bee gut and food supplies based on pollen of the Amazonian bee Melipona seminigra, with the purpose of knowing better the microorganisms associated to this bee and the process of storage and preservation of the bee pollen in the colony, glimpsing biotechnological applications. The experiments were carried out in three phases, starting with the description of the bacterial microbiota present in the pollen supply of Melipona seminigra bee, using independent culture methods (direct sequencing of microbial DNA samples) and culture-dependent methods ( Bacterial culture). Bacterial isolates obtained by pollen and larval food cultivation were evaluated for their hydrolytic enzyme production. Finally, the study of the Melipona seminigra gut microbiota was carried out based on cloning and sequencing of the 16SrRNA gene. It was identified 26 bacterial genera associated to pollen provisions of Melipona seminigra, many of which are of environmental in origin and related to natural and / or industrial fermentation processes. Changes in the bacterial composition of pollen from its collection until maturation suggest that the production of this food is mediated by a microbial succession process. Most of the bacteria isolated from pollen produce lipases, amylases, proteases and cellulases with high enzymatic indexes, indicating the potential of them for the bioprospection of enzymes of industrial interest. Regarding to the gut microbiota it was demonstrated that the bacterial populations colonize differentially the morphofunctional parts of gut, being the greater diversity of bacteria found in the middle and posterior intestines. This work resulted in unprecedented data on M. seminigra microbiota, which largely contribute to a better understanding of the complex and fascinating symbiotic relationships between social bees and microorganisms.
As abelhas, assim como outros insetos sociais, apresentam complexas interações simbióticas com microrganismos, que vão desde o nível do indivíduo (abelha) até os diferentes microambientes do ninho/colônia. Estas relações afetam diretamente a imunidade e o potencial nutricional das abelhas bem como influenciam processos produtivos dentro da colônia, como a produção e armazenamento de alimentos. Considerando que: i) são escassos os estudos sobre a microbiota de abelhas silvestres, sendo grande parte da literatura voltada para as abelhas exóticas Apis mellifera; ii) o conhecimento dos microrganismos simbióticos contribue para o entendimento das relações ecológicas que garantem a homeostase da colônia bem como fornece ferramentas para a prospecção de produtos de interesse biotecnológico; iii) a produção fermentativa do pólen, principal alimento da colônia, é um processo pouco conhecido embora fundamental para o desenvolvimento das colônias de abelhas sociais; o objetivo deste trabalho foi elucidar as comunidades bacterianas associadas às provisões alimentares à base de pólen da abelha amazônica Melipona seminigra e ao seu intestino, com a finalidade de se conhecer melhor os microrganismos associados à esta abelha e ao armazenamento e preservação do pólen na colônia, vislumbrando aplicações biotecnológicas. Os experimentos deste trabalho foram realizados em três fases, iniciando-se com a descrição da microbiota bacteriana presente em potes e células de alimento da abelha Melipona seminigra, por meio de métodos independentes de cultivo (sequenciamento direto de DNA microbiano das amostras) e métodos dependentes de cultivo (cultivo bacteriano). Os isolados bacterianos obtidos pelo cultivo do pólen e alimento larval foram avaliados quanto ao seu potencial de produção de enzimas hidrolíticas e, por fim, realizou-se o estudo da microbiota bacteriana intestinal, a partir da clonagem gênica e sequenciamento do gene 16S rRNA. Foram identificados 26 gêneros bacterianos associados às provisões polínicas de Melipona seminigra, muitos dos quais são de origem ambiental e relacionados com processos fermentativos naturais e/ou industriais. Mudanças na composição bacteriana do pólen, desde a sua coleta até sua maturação sugerem que a produção deste alimento é mediada por um processo de sucessão microbiana. Grande parte das bactérias isoladas do pólen produz lipases, amilases, proteases e celulases com altos índices enzimáticos, indicando o potencial dessas bactérias para a bioprospecção de enzimas de interesse industrial. Em relação à microbiota intestinal, demonstrou-se que as populações bacterianas colonizam diferencialmente as partes morfofuncionais do intestino, sendo a maior diversidade de bactérias encontradas nos intestinos médios e posteriores. Este trabalho resultou em dados inéditos acerca da microbiota associada a abelhas M. seminigra, que contribuem para o melhor entendimento das complexas e fascinantes relações simbióticas entre abelhas sociais e microrganismos.
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