Publications by authors named "Luciana Leomil"

The genomic monitoring of SARS-CoV-2 variants of concern (VOCs) in riverine and sewage water has been widely used as an epidemiological tool worldwide. But its utility for epidemiological assessments still needs to be evaluated in some areas. Our study encompassed thirteen Brazilian rivers spanning a vast urban expanse across the states of Rio de Janeiro, São Paulo, and Paraná.

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  • Mollusc rearing in southeast Brazil has significantly declined, with scallop production dropping from 51.2 tons in 2016 to 10.2 tons in 2022 due to unknown reasons.
  • The study investigated water quality trends and environmental factors impacting the production of scallops, particularly focusing on Nodipecten nodosus over the last decade.
  • Findings indicate that declines in scallop spat production are linked to warmer water temperatures, decreased levels of Chlorophyll a, and increased presence of harmful bacteria, suggesting that global warming and poor seawater quality are key contributors to the industry’s collapse.
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Background: Few studies have focused on microbial diversity in indoor environments of ships, as well as the role of the microbiome and its ecological interconnections. In this study, we investigated the microbiome and virome present on the internal surfaces of a polar ship in different stages (beginning, during, and at the end) of the Brazilian Antarctic expedition in order to evaluate abundance of microorganisms in different periods.

Objectives And Methods: We used shotgun metagenomic analysis on pooled samples from sampling surfaces in the ship's interior to track the microbial diversity.

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  • - The study examines the microbial diversity in sediments from Airo Lake, a floodplain lake in the Amazon, using metagenomics and biogeochemical analysis to understand the impact of the Negro River on the lake's environment.
  • - Three sediment layers were analyzed, revealing distinct microbiomes: older, deeper sediments had a higher abundance of specific bacteria like Burkholderia, while more recent layers contained different microbes like Thermococcus, indicating changes over time.
  • - A significant number of metagenome-assembled genomes (MAGs) identified in the older strata are linked to unknown taxa, suggesting potential new species, and show enrichment in sulfur cycle genes, highlighting the complexity of microbial interactions in this ecosystem.
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Polar freshwater ecosystems are characterized by a distinct microbiota. However, little is known about viral diversity and abundance, especially regarding the ecology of RNA viruses. We used shotgun metagenomic analysis on samples from Antarctic ecosystems, and report here the characterization of the virome fraction, from different lakes located in the South Shetland Islands (Penguin, Ardley, Deception and King George Island) in the Peninsula Antarctica, in the summer season 2020.

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Rainwater harvesting has been considered an affordable practice to supplement the conventional sources of water supply for potable and non-potable uses worldwide. This study characterizes the viral community found in roof-harvested rainwater (RHRW) samples obtained under different rain volumes in a densely urbanized low-income region in Rio de Janeiro, Brazil. Three pilot-scale standardized metal-sheet roofs (same catchment area, material age, and slope - 3%) were installed in the study area aiming at obtaining more reliable and representative samples.

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In the late Quaternary, glacial-interglacial transitions are marked by major environmental changes. Glacial periods in the western equatorial Atlantic (WEA) are characterized by high continental terrigenous input, which increases the proportion of terrestrial organic matter (e.g.

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  • The study investigates microbial diversity in marine sediments of Guanabara Bay, Brazil, using metagenomics and biogeochemical tools across various sediment depths.
  • Findings reveal that methanogens dominate at shallower depths (1 mbsf), while sulfate-reducing microbes are more prevalent in deeper layers (4 mbsf).
  • A novel microbial order called Guanabacteria was discovered, showcasing distinct genetic traits relevant to sulfur and carbon cycles, highlighting the complex interactions and adaptations of microbial communities in impacted ecosystems.
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  • The study explores two strains of filamentous cyanobacteria from turf ecosystems in the Abrolhos Bank, Brazil, highlighting their complete genome sequences and physiological traits.
  • The strains, Adonisia turfae CCMR0081 and CCMR0082, have genome sizes around 8 Mbp and show distinct types of chromatic acclimation, correlating with their photosynthetic pigment regulation.
  • Both strains possess a rich variety of gene clusters for secondary metabolite production and can thrive in warmer temperatures, shedding light on their ecological roles in reef systems.
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  • A649 is a novel bacterial species isolated from the healthy pufferfish Sphoeroides spengleri, classified as Enterovibrio baiacu sp nov.
  • Genomic analysis shows A649 has significantly low amino acid/nucleotide identity (less than 95%) and genome similarity (less than 70%) compared to its closest relatives.
  • The complete genome of strain A649 is approximately 5.4 million base pairs long and contains 4,826 coding genes, with unique features for distinguishing it from other Enterovibrio species.
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  • - The genome sequence of Shewanella corallii strain A687 was obtained from a pufferfish species called Sphoeroides spengleri.
  • - This genetic assembly is made up of 5,215,037 base pairs and includes 284 separate fragments known as contigs.
  • - The G+C content of the genome is 50.3%, which indicates the percentage of guanine and cytosine nucleotides in the DNA.
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Unplanned oil spills during offshore oil production are a serious problem for the industry and the marine environment. Here we assess the biodegradation potential of marine microorganisms from three water depths in the Campos Basin (South Atlantic Ocean): (i) 5 m (surface), (ii) ∼80 m (chlorophyll maximum layer), and (iii) ∼1200 m (near the bottom). After incubating seawater samples with or without crude oil for 52 days, we used metagenomics and classic microbiology techniques to analyze microbial abundance and diversity, and measured physical-chemical parameters to better understand biodegradation processes.

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  • The study investigates the aftermath of the Fundão tailings dam failure on the water quality of the Doce River by analyzing metagenomics and physicochemical data shortly after the disaster and again at 6 and 10 months later.
  • Immediately following the dam failure, water quality deteriorated significantly, with extremely high levels of suspended particulate matter, turbidity, and dissolved metals, while dissolved oxygen fell below legal standards in some areas.
  • Six months post-disaster, water quality improved, aligning with Brazilian guidelines, but notable changes occurred in microbial communities, showing increased diversity and alterations in metabolic functions related to iron and nitrogen cycling.
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Brazil, which is hyperendemic for dengue virus (DENV), has had recent Zika (ZIKV) and (CHIKV) Chikungunya virus outbreaks. Since March 2016, CHIKV is the arbovirus infection most frequently diagnosed in Rio de Janeiro. In the analysis of 1835 syndromic patients, screened by real time RT-PCR, 56.

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We report here the genome sequences of the novel isolates G62 and G98 from rhodoliths. The nearly complete genomes consisted of 4.7 Mbp (4,233 coding sequences [CDS]) for G62 and 4.

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  • * A three-year study in Ishigaki Island showed high nutrient levels and microbial abundance, with concern over correlations between high turf cover, low coral cover, and low fish biomass.
  • * The research suggests that multiple stressors like eutrophication, overfishing, and climate change are synergistically harming coral reefs in high-energy environments, potentially leading to their collapse.
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Changes in environmental conditions can influence sponges and their holobionts. The present study investigated the effect of upwelling and anthropogenic pollution on the bioactivity of marine sponges, microbial communities and functional genes, and composition of their chemical compounds. The species Dysidea etheria, Darwinella sp.

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Descriptive clinical data help to reveal factors that may provoke Zika virus (ZIKV) neuropathology. The case of a 24-year-old female with a ZIKV-associated severe acute neurological disorder was studied. The levels of ZIKV in the cerebrospinal fluid (CSF) were 50 times higher than the levels in other compartments.

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  • - Marine sponges host complex microbial communities that may be responsible for producing secondary metabolites, like bromopyrrole alkaloids, which have notable biological activities.
  • - Research on sponge species Agelas spp. and Tedania brasiliensis revealed distinct microbial halogenases, indicating a species-specific presence and a correlation between halogenase encoding bacteria abundance and bromopyrrole production.
  • - The study suggests that sponges with numerous CRISPR sequences, like Agelas spp., may protect themselves from phage infections, while phages can facilitate the horizontal transfer of halogenases among holobionts, especially in more adaptable hosts like Tedania spp.
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Harmful cyanobacterial blooms have become increasingly common in freshwater ecosystems in recent decades, mainly due to eutrophication and climate change. Water becomes unreliable for human consumption. Here, we report a comprehensive study carried out to investigate the water quality of several Campina Grande reservoirs.

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Two Gram-negative, motile, aerobic bacteria isolated from waters of the Abrolhos Bank were classified through a whole genome-based taxonomy. Strains PEL67E and PEL68C shared 99% 16S rRNA and dnaK sequence identity with Alteromonas marina SW-47 and Alteromonas macleodii ATCC 27126. In silico DNA-DNA Hybridization, i.

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  • The study focuses on the diversity and structure of virus assemblages in the Amazon River-ocean continuum, highlighting their importance in global carbon and nutrient cycling.
  • Researchers collected viral DNA sequences from 12 locations along the river and plume, yielding 29,358 scaffolds and 15 new complete viral genomes, revealing distinct virome characteristics between the river and plume ecosystems.
  • Findings indicate that bacteriophages were widespread, while eukaryotic viruses were more prevalent in the river; the study emphasizes the influence of water physical and chemical parameters, especially salinity, on viral distribution and contributes to understanding the role of viruses in the organic matter cycle.
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As coral reef habitats decline worldwide, some reefs are transitioning from coral- to algal-dominated benthos with the exact cause for this shift remaining elusive. Increases in the abundance of microbes in the water column has been correlated with an increase in coral disease and reduction in coral cover. Here we investigated how multiple reef organisms influence microbial communities in the surrounding water column.

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One consequence of oil production is the possibility of unplanned accidental oil spills; therefore, it is important to evaluate the potential of indigenous microorganisms (both prokaryotes and eukaryotes) from different oceanic basins to degrade oil. The aim of this study was to characterize the microbial response during the biodegradation process of Brazilian crude oil, both with and without the addition of the dispersant Corexit 9500, using deep-sea water samples from the Amazon equatorial margin basins, Foz do Amazonas and Barreirinhas, in the dark and at low temperatures (4°C). We collected deep-sea samples in the field (about 2570 m below the sea surface), transported the samples back to the laboratory under controlled environmental conditions (5°C in the dark) and subsequently performed two laboratory biodegradation experiments that used metagenomics supported by classical microbiological methods and chemical analysis to elucidate both taxonomic and functional microbial diversity.

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The emergence of Zika virus (ZIKV) infection has stimulated several research groups to study and collaborate to understand virus biology and pathogenesis. These efforts may assist with the development of antiviral drugs, vaccines and diagnostic tests, as well as to promote advancements in public health policies. Here, we aim to develop standard protocols for propagation, titration, and purification of ZIKV strains, by systematically testing different cell types, kinetics, multiplicity of infection and centrifugation protocols.

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