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Background Mangroves are complex and dynamic coastal ecosystems under frequent fluctuations in physicochemical conditions related to the tidal regime. The frequent variation in organic matter concentration, nutrients, and oxygen availability, among other factors, drives the microbial community composition, favoring syntrophic populations harboring a rich and diverse, stress-driven metabolism. Mangroves are known for their carbon sequestration capability, and their complex and integrated metabolic activity is essential to global biogeochemical cycling. Here, we present a metabolic reconstruction based on the genomic functional capability and flux profile between sympatric MAGs co-assembled from a tropical restored mangrove. Results Eleven MAGs were assigned to six Bacteria phyla, all distantly related to the available reference genomes. The metabolic reconstruction showed several potential coupling points and shortcuts between complementary routes and predicted syntrophic interactions. Two metabolic scenarios were drawn: a heterotrophic scenario with plenty of carbon sources and an autotrophic scenario with limited carbon sources or under inhibitory conditions. The sulfur cycle was dominant over methane and the major pathways identified were acetate oxidation coupled to sulfate reduction, heterotrophic acetogenesis coupled to carbohydrate catabolism, ethanol production and carbon fixation. Interestingly, several gene sets and metabolic routes similar to those described for wastewater and organic effluent treatment processes were identified. Conclusion The mangrove microbial community metabolic reconstruction reflected the flexibility required to survive in fluctuating environments as the microhabitats created by the tidal regime in mangrove sediments. The metabolic components related to wastewater and organic effluent treatment processes identified strongly suggest that mangrove microbial communities could represent a resourceful microbial model for biotechnological applications that occur naturally in the environment.

Background The Rhizobiales (Proteobacteria) order is an abundant and diverse group of microorganisms, being extensively studied for its lifestyle based on the association with plants, animals, and humans. New studies have demonstrated that the last common ancestor (LCA) of Rhizobiales had a free-living lifestyle, but the phylogenetic and metabolism characterization of basal lineages remains unclear. Here, we used a high-resolution phylogenomic approach to test the monophyly of the Aestuariivirgaceae family, a new taxonomic group of Rhizobiales. Furthermore, a deep metabolic investigation provided an overview of the main functional traits that can be associated with its lifestyle. We hypothesized that the presence of pathways (e.g., Glycolysis/Gluconeogenesis) and the absence of pathogenic genes would be associated with a free-living lifestyle in Aestuariivirgaceae. Results Using high-resolution phylogenomics approaches, our results revealed a clear separation of Aestuariivirgaceae into a distinct clade of other Rhizobiales family, suggesting a basal split early group and corroborate the monophyly of this group. A deep functional annotation indicated a metabolic versatility, which includes putative genes related to sugar degradation and aerobic respiration. Furthermore, many of these traits could reflect a basal metabolism and adaptations of Rhizobiales, as such the presence of Glycolysis/Gluconeogenesis pathway and the absence of pathogenicity genes, suggesting a free-living lifestyle in the Aestuariivirgaceae members. Conclusions Aestuariivirgaceae (Rhizobiales) family is a monophyletic taxon of the Rhizobiales with a free-living lifestyle and a versatile metabolism that allows these microorganisms to survive in the most diverse microbiomes, demonstrating their adaptability to living in systems with different conditions, such as extremely cold environments to tropical rivers.

The COVID-19 pandemic had a widespread global impact and presented numerous challenges. The emergence of SARS-CoV-2 variants has changed transmission rates and immune evasion, possibly impacting the severity. This study aims to investigate the impact of variants on clinical outcomes in southern Brazil. In total, samples from 277 patients, hospitalized and non-hospitalized, were collected between March 2020 and March 2021, before the vaccine was made widely available to the general population in Brazil. Whole genome sequencing of SARS-CoV-2 was performed and bioinformatics and biostatistics analyses were implemented on molecular and clinical data, respectively. The study identified significant demographic and clinical differences. The hospitalized group exhibited a higher proportion of males (51.9%) and an increased prevalence of comorbidities, including hypertension (66.0%), obesity (42.6%), and chronic kidney disease (23.6%). Patients were identified with twelve SARS-CoV-2 strains, predominantly B.1.1.28 and B.1.1.33 in the early 2020 first wave, and P.1 overlapping in the late 2020 and early 2021 second wave of COVID-19. Significant differences in hospitalization rates were found among patients infected with the different SARS-CoV-2 lineages: B.1.1.33 (46.0%), B.1.1.28 (65.9%), and P.1 (97.9%). Severity markers, such as pneumonia (62.5%, p=0.002), acute respiratory distress syndrome (ARDS, 72.9%, p<0.001), and oxygen support >6 L/min O (64.6%, p<0.001), were more frequent in patients from the second wave. These findings highlight the impact of different variants on the clinical evolution and prognosis of COVID-19, especially when comparing the first and second waves of the pandemic. The study underscores the association between SARS-CoV-2 strains and COVID-19 severity by integrating clinical and viral data for public health responses during different pandemic phases, highlighting the importance of adapting pandemic strategies as the pandemic evolves.

Chikungunya virus (CHIKV) infection often results in a chronic joint condition known as Post-Chikungunya Chronic Inflammatory Joint Disease (pCHIKV-CIJD). This condition disrupts individuals’ daily lives and contributes to increased healthcare expenditure. This study investigated the molecular mechanisms underlying pCHIKV-CIJD development by analyzing RNA transcripts, including small RNAs, of whole blood from CHIKV-infected patients. By comparing patients who evolved to pCHIKV-CIJD with those who did not, we identified molecular signatures associated with chronification in acute and post-acute disease phases. These molecules were primarily associated with an altered immune response regulation. Notably, LIFR , an immune receptor that enhanced IL-6 transcription, was down-regulated in the acute phase of pCHIKV-CIJD patients, while its inhibitor, hsa-miR-98-5p, was up-regulated in these individuals. Other downregulated genes include members of immune mechanisms whose impairment can lead to a reduction in the first line of antiviral response, thereby promoting virus persistence for a longer period in these patients. Additionally, pCHIKV-CIJD patients exhibited reduced transcript levels of MMP8 , LFT , and DDIT4 , genes already implicated in the pathological process of other types of inflammatory arthritis and seemingly relevant for pCHIKV-CIJD development. Overall, our findings provide insights into the early molecular mechanisms involved in the chronification and highlight potential targets for further investigation.

Chikungunya-fever (CHIKF) remains a public health major issue. It is clinically divided into three phases: acute, post-acute and chronic. Chronic cases correspond to 25-40% individuals and, though most of them are characterized by long-lasting arthralgia alone, many of them exhibit persistent or recurrent inflammatory signs that define post-Chikungunya chronic inflammatory joint disease (pCHIKV-CIJD). We aimed to identify early clinical markers of evolution to pCHIKV-CIJD during acute and post-acute phases. We studied a prospective cohort of CHIKF-confirmed volunteers with longitudinal clinical data collection from symptoms onset up to 90 days, including a 21-day visit (D21). Of 169 patients with CHIKF, 86 (50.9%) completed the follow-up, from whom 39 met clinical criteria for pCHIKV-CIJD (45.3%). The relative risk of chronification was higher in women compared to men (RR = 1.52; 95% CI = 1.15-1.99; FDR = 0.03). None of the symptoms or signs presented at D0 behaved as an early predictor of pCHIKV-CIJD, while being symptomatic at D21 was a risk factor for chronification (RR = 1.31; 95% CI = 1.09-1.55; FDR = 0.03). Significance was also observed for joint pain (RR = 1.35; 95% CI = 1.12-1.61; FDR = 0.02), reported edema (RR = 3.61; 95% CI = 1.44-9.06; FDR = 0.03), reported hand and/or feet small joints edema (RR = 4.22; 95% CI = 1.51-11.78; FDR = 0.02), and peri-articular edema observed during physical examination (RR = 2.89; 95% CI = 1.58-5.28; FDR = 0.002). Furthermore, patients with no findings in physical examination at D21 were at lower risk of chronic evolution (RR = 0.41, 95% CI = 0.24-0.70, FDR = 0.01). Twenty-nine pCHIKV-CIJD patients had abnormal articular ultrasonography (90.6% of the examined). The most common findings were synovitis (65.5%) and joint effusion (58.6%). This cohort has provided important insights into the prognostic evaluation of CHIKF. Symptomatic sub-acute disease is a relevant predictor of evolution to chronic arthritis with synovitis, drawing attention to joint pain, edema, multiple articular involvement including small hand and feet joints as risk factors for chronification beyond three months, especially in women. Future studies are needed to accomplish the identification of accurate and early biomarkers of poor clinical prognosis, which would allow better understanding of the disease's evolution and improve patients' management, modifying CHIKF burden on global public health.

Soybean is Brazil´s most important grain crop and accumulates over 250 kg N ha −1 , principally from biological N 2 fixation. The residual N benefit depends heavily on the quantity of the belowground N at harvest, much of which cannot be directly recovered in roots. The purpose of this study was to investigate different aspects of the 15 N shoot-labelling technique to quantify non-recoverable N in rhizodeposits. Three pot experiments were performed and the aerial tissue was labelled with highly enriched 15 N-labelled urea or glutamine at between 27 and 39 days after planting. In all experiments sequential harvests were taken until late grain-filling phase. After only 2 or 3 days between 5.8 and 21.3% of enriched N was found in the soil but the excess 15 N deposited until the final harvest was in all cases less than twice this amount, respectively. Evidence obtained suggested that this early deposition of labelled N was an artefact of the labelling technique. Discounting this initial tracer N decreased estimates of rhizodeposited N by between 51 and 66%. Nodules were much lower in 15 N enrichment than roots. Nodule N constituted 39 to 76% of belowground N, such that the inclusion of none or all of this N to calculate the 15 N enrichment of the roots increased the estimates of rhizodeposited N by between 34 and 58%. We conclude that even if the immediate post-labelling deposition of enriched N is discounted, estimates of rhizodeposited N of nodulated legumes will not be reliable.

Background Multisystem Inflammatory Syndrome in Children (MIS-C) is a life-threatening complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which manifests as a hyper inflammatory process with multiorgan involvement in predominantly healthy children in the weeks following mild or asymptomatic coronavirus disease 2019 (COVID-19). However, host monogenic predisposing factors to MIS-C remain elusive. Methods Herein, we used whole exome sequencing (WES) on 16 MIS-C Brazilian patients to identify single nucleotide/InDels variants as predisposition factors associated with MIS-C. Results We identified ten very rare variants in eight genes ( FREM1 , MPO , POLG , C6 , C9 , ABCA4 , ABCC6 , and BSCL2 ) as the most promising candidates to be related to a higher risk of MIS-C development. These variants may propitiate a less effective immune response to infection or trigger the inflammatory response or yet a delayed hyperimmune response to SARS-CoV-2. Protein–Protein Interactions (PPIs) among the products of the mutated genes revealed an integrated network, enriched for immune and inflammatory response mechanisms with some of the direct partners representing gene products previously associated with MIS-C and Kawasaki disease (KD). In addition, the PPIs direct partners are also enriched for COVID-19-related gene sets. HLA alleles prediction from WES data allowed the identification of at least one risk allele in 100% of the MIS-C patients. Conclusions This study is the first to explore host MIS-C-associated variants in a Latin American admixed population. Besides expanding the spectrum of MIS-C-associated variants, our findings highlight the relevance of using WES for characterising the genetic interindividual variability associated with COVID-19 complications and ratify the presence of overlapping/convergent mechanisms among MIS-C, KD and COVID-19, crucial for future therapeutic management.

Many molecular mechanisms that lead to the host antibody response to COVID-19 vaccines remain largely unknown. In this study, we used serum antibody detection combined with whole blood RNA-based transcriptome analysis to investigate variability in vaccine response in healthy recipients of a booster (third) dose schedule of the mRNA BNT162b2 vaccine against COVID-19. The cohort was divided into two groups: (1) low-stable individuals, with antibody concentration anti-SARS-CoV IgG S1 below 0.4 percentile at 180 days after boosting vaccination; and (2) high-stable individuals, with antibody values greater than 0.6 percentile of the range in the same period (median 9525 [185–80,000] AU/mL). Differential gene expression, expressed single nucleotide variants and insertions/deletions, differential splicing events, and allelic imbalance were explored to broaden our understanding of the immune response sustenance. Our analysis revealed a differential expression of genes with immunological functions in individuals with low antibody titers, compared to those with higher antibody titers, underscoring the fundamental importance of the innate immune response for boosting immunity. Our findings also provide new insights into the determinants of the immune response variability to the SARS-CoV-2 mRNA vaccine booster, highlighting the significance of differential splicing regulatory mechanisms, mainly concerning HLA alleles, in delineating vaccine immunogenicity.

Transcriptome studies have reported the dysregulation of cell cycle-related genes and the global inhibition of host mRNA translation in COVID-19 cases. However, the key genes and cellular mechanisms that are most affected by the severe outcome of this disease remain unclear. For this work, the RNA-seq approach was used to study the differential expression in buffy coat cells of two groups of people infected with SARS-CoV-2: (a) Mild, with mild symptoms; and (b) SARS (Severe Acute Respiratory Syndrome), who were admitted to the intensive care unit with the severe COVID-19 outcome. Transcriptomic analysis revealed 1009 up-regulated and 501 down-regulated genes in the SARS group, with 10% of both being composed of long non-coding RNA. Ribosome and cell cycle pathways were enriched among down-regulated genes. The most connected proteins among the differentially expressed genes involved transport dysregulation, proteasome degradation, interferon response, cytokinesis failure, and host translation inhibition. Furthermore, interactome analysis showed Fibrillarin to be one of the key genes affected by SARS-CoV-2. This protein interacts directly with the N protein and long non-coding RNAs affecting transcription, translation, and ribosomal processes. This work reveals a group of dysregulated processes, including translation and cell cycle, as key pathways altered in severe COVID-19 outcomes.

Background X-linked agammaglobulinemia (XLA) is an Inborn Errors of Immunity (IEI) characterized by pan-hypogammaglobulinemia and low numbers of B lymphocytes due to mutations in BTK gene. Usually, XLA patients are not susceptible to respiratory tract infections by viruses and do not present interstitial lung disease (ILD) such as bronchiolitis obliterans (BO) as a consequence of acute or chronic bacterial infections of the respiratory tract. Although many pathogenic variants have already been described in XLA, the heterogeneous clinical presentations in affected patients suggest a more complex genetic landscape underlying this disorder. Case presentation We report two pediatric cases from male siblings with X-Linked Agammaglobulinemia and bronchiolitis obliterans, a phenotype not often observed in XLA phenotype. The whole-exome sequencing (WES) analysis showed a rare hemizygous missense variant NM_000061.2(BTK):c.1751G>A(p.Gly584Glu) in  BTK gene of both patients. We also identified a gain-of-function mutation in TGFβ1 (rs1800471) previously associated with transforming growth factor-beta1 production, fibrotic lung disease, and graft fibrosis after lung transplantation. TGFβ1 plays a key role in the regulation of immune processes and inflammatory response associated with pulmonary impairment. Conclusions Our report illustrates a possible role for WES in patients with known inborn errors of immunity, but uncommon clinical presentations, providing a personalized understanding of genetic basis, with possible implications in the identification of potential treatments, and prognosis for patients and their families.