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Stingless bees are a diverse group with a relevant role in pollinating native species. Its diet is rich in carbohydrates and proteins, by collecting pollen and nectar supplies the development of its offspring. Fermentation of these products is associated with microorganisms in the colony. However, the composition of microorganisms that comprise this microbiome and its fundamental role in colony development is still unclear. To characterize the colonizing microorganisms of larval food in the brood cells of stingless bees Frieseomelitta varia , Melipona quadrifasciata , Melipona scutellaris , and Tetragonisca angustula , we have utilized molecular and culture-based techniques. Bacteria of the phyla Firmicutes, Proteobacteria, Actinobacteria, and fungi of the phyla Ascomycota, Basidiomycota, Mucoromycota, and Mortierellomycota were found. Diversity analysis showed that F. varia had a greater diversity of bacteria in its microbiota, and T. angustula had a greater diversity of fungi. The isolation technique allowed the identification of 189 bacteria and 75 fungi. In summary, this research showed bacteria and fungi associated with the species F. varia , M. quadrifasciata , M. scutellaris , and T. angustula , which may play an essential role in the survival of these organisms. Besides that, a biobank with bacteria and fungus isolates from LF of Brazilian stingless bees was created, which can be used for different studies and the prospection of biotechnology compounds.

•The energy-adjusted dietary inflammatory index was associated with markers of insulin resistance, inflammation, and body adiposity.•The energy-adjusted dietary inflammatory index was inversely correlated with the abundance of the Eubacterium.xylanophilum.group.•The energy-adjusted dietary inflammatory index was directly correlated with the abundance of Actinomyces.•Actinomyces were significantly more abundant in the highest (most proinflammatory) energy-adjusted dietary inflammatory index quartile.•Actinomyces could be involved in the association between the dietary inflammatory index with visceral adiposity. To deepen the understanding of the influence of diet on weight gain and metabolic disturbances, we examined associations between diet-related inflammation and body composition and fecal bacteria abundances in participants of the Nutritionists’ Health Study. Early-life, dietary and clinical data were obtained from 114 women aged ≤45 years. A validated food frequency questionnaire was used to calculate the energy-adjusted dietary inflammatory index (E-DII). Participants’ data were compared by E-DII quartiles using ANOVA or Kruskal-Wallis. Associations of DXA-determined body composition with the E-DII were tested by multiple linear regression using DAG-oriented adjustments. Fecal microbiota was analyzed targeting the V4 region of the 16S rRNA gene. Spearman correlation coefficients were used to test linear associations; differential abundance of genera across the E-DII quartiles was assessed by pair-wise comparisons. E-DII score was associated with total fat (b=1.80, p<0.001), FMI (b=0.08, p<0.001) and visceral fat (b=1.19, p=0.02), independently of maternal BMI, birth type and breastfeeding. E-DII score was directly correlated to HOMA-IR (r=0.30; p=0.004), C-reactive protein (r=0.29; p=0.003) and to the abundance of Actinomyces, and inversely correlated to the abundance of Eubacterium.xylanophilum.group. Actinomyces were significantly more abundant in the highest (most proinflammatory) E-DII quartile. Association of E-DII with markers of insulin resistance, inflammation, body adiposity and certain gut bacteria are consistent with beneficial effects of anti-inflammatory diet on body composition and metabolic profile. Bacterial markers, such as Actinomyces, could be involved in the association between the dietary inflammation with visceral adiposity. Studies designed to explore how a pro-inflammatory diet affects both central fat deposition and gut microbiota are needed.

Background Triatoma infestans is the main vector of Chagas disease in the Southern Cone. The resistance to pyrethroid insecticides developed by populations of this species impairs the effectiveness of vector control campaigns in wide regions of Argentina. The study of the global transcriptomic response to pyrethroid insecticides is important to deepen the knowledge about detoxification in triatomines. Methodology and findings We used RNA-Seq to explore the early transcriptomic response after intoxication with deltamethrin in a population of T. infestans which presents low resistance to pyrethroids. We were able to assemble a complete transcriptome of this vector and found evidence of differentially expressed genes belonging to diverse families such as chemosensory and odorant-binding proteins, ABC transporters and heat-shock proteins. Moreover, genes related to transcription and translation, energetic metabolism and cuticle rearrangements were also modulated. Finally, we characterized the repertoire of previously uncharacterized detoxification-related gene families in T. infestans and Rhodnius prolixus. Conclusions and significance Our work contributes to the understanding of the detoxification response in vectors of Chagas disease. Given the absence of an annotated genome from T. infestans, the analysis presented here constitutes a resource for molecular and physiological studies in this species. The results increase the knowledge on detoxification processes in vectors of Chagas disease, and provide relevant information to explore undescribed potential insecticide resistance mechanisms in populations of these insects.

Rhodnius prolixus is a vector of Chagas disease and has become a model organism to study physiology, behavior, and pathogen interaction. The publication of its genome allowed initiating a process of comparative characterization of the gene expression profiles of diverse organs exposed to varying conditions. Brain processes control the expression of behavior and, as such, mediate immediate adjustment to a changing environment, allowing organisms to maximize their chances to survive and reproduce. The expression of fundamental behavioral processes like feeding requires fine control in triatomines because they obtain their blood meals from potential predators. Therefore, the characterization of gene expression profiles of key components modulating behavior in brain processes, like those of neuropeptide precursors and their receptors, seems fundamental. Here we study global gene expression profiles in the brain of starved R. prolixus fifth instar nymphs by means of RNA sequencing (RNA-Seq). The expression of neuromodulatory genes such as those of precursors of neuropeptides, neurohormones, and their receptors; as well as the enzymes involved in the biosynthesis and processing of neuropeptides and biogenic amines were fully characterized. Other important gene targets such as neurotransmitter receptors, nuclear receptors, clock genes, sensory receptors, and takeouts genes were identified and their gene expression analyzed. We propose that the set of neuromodulatory-related genes highly expressed in the brain of starved R. prolixus nymphs deserves functional characterization to allow the subsequent development of tools targeting them for bug control. As the brain is a complex structure that presents functionally specialized areas, future studies should focus on characterizing gene expression profiles in target areas, e.g. mushroom bodies, to complement our current knowledge.

Aims To describe the abundance of major phyla and some genera in the gut microbiota of individuals according to dietary habits and examine their associations with inflammatory markers, insulin resistance, and cardiovascular risk profile. Methods A total of 268 non-diabetic individuals were stratified into groups of dietary types (strict vegetarians, lacto-ovo-vegetarians, and omnivores). The taxonomic composition and phylogenetic structure of the microbiota were obtained through the analysis of the 16S rRNA gene. Samples were clustered into operational taxonomic units at 97% similarity using GreenGenes 13.5 database. Clinical, biochemical, and circulating inflammatory markers were compared by ANOVA or Kruskal–Wallis test. Results The sample (54.2% women, mean age 49.5 years) was composed of 66 strict vegetarians, 102 lacto-ovo-vegetarians and 100 omnivores. Considering the entire sample, the greatest abundant phyla were Firmicutes (40.7 ± 15.9%) and Bacteroidetes (39.5 ± 19.9%), and no difference in abundances was found between individuals with normal and excess weight. Stratifying by dietary types, the proportion of Firmicutes was lower and of Bacteroidetes was higher in strict vegetarians when compared to lacto-ovo-vegetarians and omnivores. At the genus level, strict vegetarians had a higher Prevotella abundance and Prevotella/Bacteroides ratio than the other groups. They also had a lower proportion of Faecalibacterium than lacto-ovo-vegetarians, and both vegetarian groups had higher proportions than did omnivores. Succinivibrio and Halomonas from the Proteobacteria phylum were overrepresented in omnivores. The omnivorous group showed higher values of anthropometric data, insulin, HOMA-IR, and a worse lipid profile. Inflammatory markers exhibited a gradual and significant increase from the vegetarians and lacto-ovo-vegetarians to the omnivorous group. Conclusions There are differences in gut microbiota composition of individuals with distinct dietary habits, who differ according to their inflammatory and metabolic profiles. Based on the findings relative to bacteria abundances and on their recognized actions in the metabolism, we suggest that exposure to animal foods may favor an intestinal environment which could trigger systemic inflammation and insulin resistance-dependent metabolic disorders.

ABSTRACT The presence of genes for glycosyl hydrolases in many Acidobacteria genomes indicates an important role in the degradation of plant cell wall material. Acidobacteria bacterium AB60 was obtained from Cerrado oligotrophic soil in Brazil, where this phylum is abundant. The 16S rRNA gene analyses showed that AB60 was closely related to the genera Occallatibacter and Telmatobacter. However, AB60 grew on xylan as carbon source, which was not observed in Occallatibacter species; but growth was not detected on medium containing carboxymethyl cellulose, as observed in Telmatobacter. Nevertheless, the genome analysis of AB60 revealed genes for the enzymes involved in cellulose as well as xylan degradation. In addition to enzymes involved in xylan degradation, α-l-rhamnosidase was detected in the cultures of AB60. Functional screening of a small-insert genomic library did not identify any clones capable of carboxymethyl cellulose degradation, but open reading frames coding α-l-arabinofuranosidase and α-l-rhamnosidase were present in clones showing xylan degradation halos. Both enzymes act on the lateral chains of heteropolymers such as pectin and some hemicelluloses. These results indicate that the hydrolysis of α-linked sugars may offer a metabolic niche for slow-growing Acidobacteria, allowing them to co-exist with other plant-degrading microbes that hydrolyze β-linked sugars from cellulose or hemicellulose backbones. Acidobacteria degradation of plant polymers.

Leprosy is an infectious disease with a complex genetic and immunological background. Polymorphisms in genes that encode cytokines and receptors involved in the immune response, such as the Toll-like receptor 1 (TLR1), may be associated with disease risk. We hypothesized that polymorphisms in innate immunity genes confer susceptibility to leprosy that differs between women and men. In this study, we investigate sex differences in the association between a single nucleotide polymorphism (SNP) in TLR1 and Nucleotide-binding oligomerization domain containing 2 (NOD2) genes and leprosy susceptibility in 256 clinically classified leprosy patients and 233 control subjects in a Brazilian population. Our results showed no association between the SNP rs8057341 in NOD2 and leprosy in this population. However, the heterozygous genotype of the TLR1 SNP (rs4833095) showed a statistically significant association in women (OR = 0.54, P = 0.02). Our findings suggest that the TLR1 polymorphism was associated with an increased protection from leprosy in women.

The hemibiotrophic fungus Colletotrichum graminicola may cause severe damage to maize, affecting normal development of the plant and decreasing grain yield. In this context, understanding plant defense pathways at the inoculation site and systemically in uninoculated tissues can help in the development of genetic engineering of resistance against this pathogen. Previous work has discussed the molecular basis of maize - C. graminicola interaction. However, many genes involved in defense have not yet been exploited for lack of annotation in public databases. Here, changes in global gene expression were studied in root, male and female inflorescences of maize under local and systemic fungal infection treatments, respectively. RNA-Seq with qPCR was used to indicate genes involved in plant defense. We found that systemic acquired resistance induction in female inflorescences mainly involves accumulation of salicylic acid (SA)-inducible defense genes ( ZmNAC , ZmHSF , ZmWRKY , ZmbZIP and PR1 ) and potential genes involved in chromatin modification. Furthermore, transcripts involved in jasmonic acid (JA) and ethylene (ET) signaling pathways were also accumulated and may participate in plant immunity. Moreover, several genes were functionally re-annotated based on domain signature, indicating novel candidates to be tested in strategies involving gene knockout and overexpression in plants.

Lice are obligate ectoparasites that have co-evolved with their hosts, particularly during the transition of mammals from terrestrial to amphibious habits, as sea lions, seals and walruses, and have undergone parallel adaptations to the extreme conditions of the deep sea. By combining morphological, physiological and genomic analyses, we are shedding light on a key process for surviving prolonged submersion: respiration. Under water, lice immobilise, close their spiracles, reduce their oxygen consumption to a minimum and breathe through their tegument. The presence of haemoglobin genes in their genome also strongly suggests the ability to store oxygen during host dives. Remarkably, seal lice have no anatomical features or physiological capabilities that distinguish them from other insects. This reinforces the idea that the absence of insects in the deep sea is not due to any inherent limitations in their form or function, but rather a result of their evolutionary pathways.

Background The emergence of the new SARS-CoV-2 Omicron variant, which is known to have a large number of mutations when compared to other variants, brought to light the concern about vaccine escape, especially from the neutralization by antibodies induced by vaccination. Methods Based on viral microneutralization assays, we evaluated in 90 individuals the impact on antibody neutralization induction, against Omicron variant, by a booster dose of BNT162b2 mRNA vaccine after the CoronaVac primary vaccination scheme. Results Here we show that the percentage of seroconverted individuals 30 and 60 days after CoronaVac scheme was 16.6% and 10%, respectively. After booster dose administration, the seroconvertion rate increased to 76.6%. The neutralization mean titer against Omicron in the CoronaVac protocol decreased over time, but after the booster dose, the mean titer increased 43.1 times. Conclusions These results indicate a positive impact of this vaccine combination in the serological immune response against SARS-CoV-2 Omicron variant. Plain language summary The high transmission rates of SARS-CoV-2 favor the appearance of variants of the virus bearing a high number of changes in the genetic material, such as the Omicron variant. These changes might impact the efficacy of COVID-19 vaccines. Here, we evaluated the ability, of a highly adopted vaccination scheme in Brazil, of producing neutralizing antibodies, proteins present in the human body that bind to the virus and prevent infection, against the Omicron variant. This scheme consisted in two doses of the CoronaVac vaccine followed by an additional dose of the BNT162b2 vaccine. Our analysis showed that, before the additional dose, the number of individuals presenting neutralizing antibodies against Omicron was low and decreased over time. However, the production of neutralizing antibodies increased significantly after the BNT162b2 dose. Our findings support that this vaccination scheme improves the neutralization of Omicron. Campos et al. assessed the impact of a booster dose of BNT162b2 on antibody neutralization against the SARS-CoV-2 Omicron variant, following two doses of the CoronaVac vaccine. Neutralization mean titers against Omicron decrease over time following two doses of CoronaVac but increase again after the BNT162b2 booster, as does seroconversion.