Publications by authors named "Alexandra L Gerber"

Introduction: 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.

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Objectives: The two oyster species studied hold considerable economic importance for artisanal harvest (Crassostrea rhizophorae) and aquaculture (Crassostrea gasar). Their draft genomes will play an important role in the application of genomic methods such as RNAseq, population-based genomic scans aiming at addressing expression responses to pollution stress, adaptation to salinity and temperature variation, and will also permit investigating the genetic bases and enable marker-assisted selection of economically important traits like shell and mantle coloration and resistance to temperature and disease.

Data Description: The draft assembly size of Crassostrea gasar is 506 Mbp, and of Crassostrea rhizophorae is 584 Mbp with scaffolds N50 of 11,3 Mbp and 4,9 Mbp, respectively.

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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.

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Parkinson's disease (PD) is the second most prevalent neurodegenerative disease globally, with a fast-growing prevalence. The etiology of PD exhibits a multifactorial complex nature and remains challenging. Herein, we described clinical, molecular, and integrative bioinformatics findings from a Brazilian female affected by Early-Onset PD (EOPD) harboring a recurrent homozygous pathogenic deletion in the parkin RBR E3 ubiquitin protein ligase gene (PRKN; NM_004562.

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COVID-19 is an infectious disease caused by SARS-CoV-2 that has become a serious threat to public health owing to its rapid spread from aerosols from infected people. Despite being considered a strictly human disease, there are reports in the literature about animals with confirmed presence of the virus. Owing to the scarcity of scientific literature on the potential for infection of animals and their importance for One Health, the objective of this work was to research SARS-CoV-2 RNA in felines (Felis silvestris catus) and dogs (Canis lupus familiaris) domiciled.

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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.

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Mangroves are complex land-sea transition ecosystems whose microbiota are essential for their nutrient recycling and conservation. Brazil is the third-largest estuarine area in the world and "Baía de Todos os Santos" (BTS) is one of the largest bays of the country, with wide anthropogenic exploration. Using a metagenomic approach, we investigated composition and functional adaptability as signatures of the microbiome of pristine and anthropized areas of BTS, including those under petroleum refinery influence.

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Article Synopsis
  • Inherited genetic defects in immune system-related genes can lead to Inborn Errors of Immunity (IEI), which are challenging to diagnose due to overlapping symptoms, making accurate identification of genetic variants essential for effective treatment and counseling.
  • This study conducted genetic screening on 13 patients from Brazil's public health system to find associations between genetic variants and patient characteristics, using whole exome sequencing (WES) and a computational framework for analysis.
  • The results identified 16 disease-causing variants across nine genes in six different IEI categories, with X-Linked Agammaglobulinemia as the most common disorder in the group.
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Objectives: Inborn error of immunity (IEI) comprises a broad group of inherited immunological disorders that usually display an overlap in many clinical manifestations challenging their diagnosis. The identification of disease-causing variants from whole-exome sequencing (WES) data comprises the gold-standard approach to ascertain IEI diagnosis. The efforts to increase the availability of clinically relevant genomic data for these disorders constitute an important improvement in the study of rare genetic disorders.

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Brazil currently ranks second in absolute deaths by COVID-19, even though most of its population has completed the vaccination protocol. With the introduction of Omicron in late 2021, the number of COVID-19 cases soared once again in the country. We investigated in this work how lineages BA.

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Background: 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).

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  • Multisystem Inflammatory Syndrome in Children (MIS-C) is a severe complication related to COVID-19 that appears in mainly healthy children following mild infections, but its genetic risk factors are not well understood.
  • Researchers conducted whole exome sequencing on 16 Brazilian patients with MIS-C, identifying ten rare genetic variants in eight specific genes that may increase the risk of developing this syndrome by affecting immune responses.
  • The study highlights the potential for genetic testing to understand individual variability in COVID-19 complications and suggests overlapping mechanisms between MIS-C, Kawasaki disease, and COVID-19, which could inform future treatment strategies.
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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.

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  • During the first semester of 2021, Brazil faced a severe COVID-19 wave linked to the Gamma variant, with Delta variant cases emerging in July in Rio de Janeiro.
  • Researchers analyzed over 1,600 genomic sequences of the Delta variant to understand its spread, noting its initial concentration in Rio de Janeiro city before reaching other areas.
  • The Delta variant likely replaced Gamma due to a higher viral load, leading to increased case numbers but lower mortality rates, potentially aided by high vaccination rates in the region.
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  • The report highlights a multicentric study conducted in Brazil to assess bacterial communities and antimicrobial resistance genes (ARGs) in food-producing animals and healthy humans, using rectal swabs from various regions.
  • The findings revealed a high level of microbial diversity with over 21,000 unique species identified, alongside 405 ARGs linked to multiple antibiotic classes, including previously unreported carbapenemase-encoding genes.
  • The study emphasizes the interconnectedness of humans and animals in the spread of antimicrobial resistance, particularly in low- and middle-income countries, and advocates for enhanced surveillance through One Health approaches.
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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.

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  • This study presents the first documented case of intra-host recombination of SARS-CoV-2, involving two variants of concern: AY.33 (Delta) and P.1 (Gamma).
  • Using next-generation sequencing, the researchers identified six recombinant regions across the SARS-CoV-2 genome, particularly in the spike and nucleocapsid genes, showcasing a mix of mutations from both variants.
  • The findings highlight a potential public health risk, as the emergence of new recombinant viruses could complicate COVID-19 management and response efforts.
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In the present study, we provide a retrospective genomic epidemiology analysis of the SARS-CoV-2 pandemic in the state of Rio de Janeiro, Brazil. We gathered publicly available data from GISAID and sequenced 1927 new genomes sampled periodically from March 2021 to June 2021 from 91 out of the 92 cities of the state. Our results showed that the pandemic was characterized by three different phases driven by a successive replacement of lineages.

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  • * A study sequenced genomes from 185 samples across various Brazilian regions, revealing that P.1 and P.2 spread widely, with P.2 being dominant in most areas except Amazonas.
  • * The research indicated that both variants originated in 2020 and emphasized the necessity for ongoing monitoring and control measures due to Brazil's high transmission rates.
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Long-term infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represents a challenge to virus dispersion and the control of coronavirus disease 2019 (COVID-19) pandemic. The reason why some people have prolonged infection and how the virus persists for so long are still not fully understood. Recent studies suggested that the accumulation of intra-host single nucleotide variants (iSNVs) over the course of the infection might play an important role in persistence as well as emergence of mutations of concern.

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Chikungunya virus (CHIKV) is a re-emergent arbovirus that causes a disease characterized primarily by fever, rash and severe persistent polyarthralgia, although <1% of cases develop severe neurological manifestations such as inflammatory demyelinating diseases (IDD) of the central nervous system (CNS) like acute disseminated encephalomyelitis (ADEM) and extensive transverse myelitis. Genetic factors associated with host response and disease severity are still poorly understood. In this study, we performed whole-exome sequencing (WES) to identify HLA alleles, genes and cellular pathways associated with CNS IDD clinical phenotype outcomes following CHIKV infection.

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Arboviruses pose a major threat throughout the world and represent a great burden in tropical countries of South America. Although generally associated with moderate febrile illness, in more severe cases they can lead to neurological outcomes, such as encephalitis, Guillain-Barré syndrome, and Congenital Syndromes. In this context astrocytes play a central role in production of inflammatory cytokines, regulation of extracellular matrix, and control of glutamate driven neurotoxicity in the central nervous system.

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Article Synopsis
  • Several studies identified new SARS-CoV-2 lineages that show unique genetic features and evolutionary differences.
  • These findings highlight the ongoing mutation and adaptation of the virus.
  • Understanding these new lineages is crucial for public health responses and vaccine development.
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Emergence of novel SARS-CoV-2 lineages are under the spotlight of the media, scientific community and governments. Recent reports of novel variants in the United Kingdom, South Africa and Brazil (B.1.

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