Publications by authors named "Dennis M Junqueira"

The HIV-1 epidemic in Brazil is predominantly characterized by subtype B, except in the southern states, where subtype C (HIV-1C) is more prevalent. Continuous monitoring of this profile is essential to maintain an accurate understanding of the molecular landscape of the HIV epidemic in Brazil. In this study, we isolated and sequenced seven new HIV-1C strains from the state of Bahia, located in the Northeast region of Brazil.

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Zoonotic infections (swine-human) caused by influenza A viruses (IAVs) have been reported and linked to close contact between these species. Here, we describe eight human IAV variant infections (6 mild and 2 severe cases, including 1 death) detected in Paraná, Brazil, during 2020-2023. Genomes recovered were closely related to Brazilian swIAVs of three major lineages (1 A.

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  • Human Pegivirus-1 (HPgV-1) is commonly found in humans but its effects on pediatric cancer patients with febrile neutropenia (FN) are not well-studied.
  • In a study analyzing 30 children, it was found that 23.3% had detectable HPgV-1 RNA, with slightly higher rates in those with FN (26.7%).
  • The predominant strain in the samples was identified as HPgV-1 genotype 2, prompting further research into its potential impact on FN and the health of immunocompromised patients.
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  • Researchers studied how the H1N1 virus, originally from humans, spread to pigs in Brazil from 2009 to 2022.
  • They found that between 2009 and 2011, the virus quickly passed from people to pigs, but it mostly caused short infections that didn’t spread much after that.
  • Since 2012, there have been fewer cases of the virus moving from humans to pigs, and the virus has changed over time, making it coexist with pigs better.
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In this study, we hypothesize that HIV geographical clusters (geospatial areas with significantly higher numbers of HIV positive individuals) can behave as the highly connected nodes in the transmission network. Using data come from one of the most comprehensive demographic surveillance systems in Africa, we found that more than 70% of the HIV transmission links identified were directly connected to an HIV geographical cluster located in a peri-urban area. Moreover, we identified a single central large community of highly connected nodes located within the HIV cluster.

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  • Understanding how sexual relationships are structured in a community is important for preventing HIV among people.
  • In a study in rural KwaZulu-Natal, South Africa, researchers looked at new sexual partnerships from 2003 to 2016 to see how they were connected in the community.
  • They found many partnerships linked to areas with high HIV rates and noticed that places with more connections among people also had higher HIV prevalence.
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In South America, the evolutionary history of influenza A virus (IAV) in swine has been obscured by historically low levels of surveillance, and this has hampered the assessment of the zoonotic risk of emerging viruses. The extensive genetic diversity of IAV in swine observed globally has been attributed mainly to bidirectional transmission between humans and pigs. We conducted surveillance in swine in Brazil during 2011-2020 and characterized 107 H1N1, H1N2, and H3N2 IAVs.

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  • The surface envelope (SU) protein of feline leukemia virus (FeLV) is crucial for understanding how the virus affects cats and leads to disease, as it influences which cells the virus can infect.
  • Recombination events between exogenous and endogenous FeLV strains can produce more harmful variants, but existing methods to categorize these variants rely primarily on interference assays of different subgroups.
  • This study suggests a new classification method using molecular analysis of SU sequences, revealing key insights into how various FeLV subgroups are genetically related and proposing that phylogenetic and recombination analysis can enhance our understanding of FeLV's phenotypic diversity.
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Bovine alphaherpesvirus 5 causes meningoencephalitis in cattle, belongs to the family, and can be divided into subtypes a, b, and c. Limited information is available about subtype c. Here, we report the complete genome sequences of two strains, P160/96, and ISO97/45, isolated from cattle in southeast Brazil.

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  • * Researchers sequenced near-complete HIV genomes from samples collected in Cameroon and the Democratic Republic of the Congo between 2001 and 2006, identifying multiple strains, including four new CRF01_AE genomes.
  • * Phylogenetic analysis shows these new African strains act as a link between earlier Central African and the more widespread Asian, European, and American strains, suggesting the common ancestor of CRF01_AE emerged in the early 1970s.
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The HoBi-like pestivirus (HoBiPeV), currently classified as Pestivirus H species, is a pathogen associated with a broad spectrum of clinical manifestations in ruminants, particularly in cattle. Since HoBiPeV complete genome sequencing data is scarce, in the present study we described five nearly complete new Brazilian HoBiPeV genomes and further perform a more complete genetic and evolutionary characterization with all additional genome sequences available in the GenBank database. Entropy and selection pressure analysis showed the E2 gene, a surface glycoprotein, is the most variable gene, which also displays the greatest number of sites under positive selection.

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Purpose Of Review: A major goal of public health in relation to HIV/AIDS is to prevent new transmissions in communities. Phylogenetic techniques have improved our understanding of the structure and dynamics of HIV transmissions. However, there is still no consensus about phylogenetic methodology, sampling coverage, gene target and/or minimum fragment size.

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The epidemic in South Africa is characterized by high genetic diversity driven by multiple independent introductions. The bulk of these introductions occurred between 1985-2000 during which time HIV prevalence increased exponentially. Epidemic growth has stabilized in recent years with the implementation of several interventions.

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The HIV epidemic in San Mateo County is sustained by multiple overlapping risk groups and is an important hub for HIV transmission in northern California. Limited access to care has led historically to delayed clinical presentation, higher rates of opportunistic infections, and an increased prevalence of antiretroviral drug resistance. The virologic and clinical consequences of treatment within these multiple ethnic and behavioral groups are poorly understood, highlighting the need for efficient surveillance strategies that are able to elucidate transmission networks and drug resistance patterns.

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Malabsorption syndrome (MAS) is an economically important disease of young, commercially reared broilers, characterized by growth retardation, defective feather development and diarrheic faeces. Several viruses have been tentatively associated to such syndrome. Here, in order to examine potential associations between enteric viruses and MAS, the faecal viromes of 70 stool samples collected from diseased (n = 35) and healthy (n = 35) chickens from seven flocks were characterized and compared.

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Feline immunodeficiency virus (FIV), like other retroviruses, displays large genomic divergence when different isolates are compared. In this study, 31 FIV positive samples of domestic cats from Porto Alegre, RS, Brazil were used aiming at a detailed genomic characterization and a better understanding of the molecular epidemiology of the virus in Brazil. The proviral env genes were partially amplified, sequenced and compared with another 237 sequences from different continents.

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The human displacement and sexual behavior are the main factors driving the HIV-1 pandemic to the current profile. The intrinsic structure of the HIV transmission among different individuals has valuable importance for the understanding of the epidemic and for the public health response. The aim of this study was to characterize the HIV-1 subtype B (HIV-1B) epidemic in South America through the identification of transmission links and infer trends about geographical patterns and median time of transmission between individuals.

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Human migration is a major process that shaped the origin and dissemination of HIV. Within HIV-1, subtype B (HIV-1B) is the most disseminated variant and it is assumed to be the causative agent in approximately 11% of all cases of HIV worldwide. Phylogenetic studies have revealed that HIV-1B emerged in Kinshasa (Africa) and was introduced into the Caribbean region via Haiti in or around 1966 by human migration.

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  • Cytokines play a crucial role in the progression of HIV, with plasma levels evaluated in extreme progressors (slow and rapid) before starting HIV treatment (HAART).
  • Significant differences were found in the levels of IL-6 and IL-10 across different HIV infection stages, with elevated levels in slow progressors before starting HAART compared to other groups.
  • These findings suggest that increased IL-6 and IL-10 levels may serve as indicators of inflammation and potentially reflect the disease progression in HIV-infected individuals, regardless of their progression status.
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  • The study aims to assess the prevalence of HIV-1 subtype B, focusing on the BPANDEMIC and BCAR clades in Latin America and to analyze how these strains spread over time in the region.
  • Researchers examined 7,654 HIV-1 subtype B sequences from 18 countries collected between 1989 and 2011, using advanced statistical methods to understand their evolution and geographic spread.
  • Findings indicate that nonpandemic BCAR strains likely spread from Caribbean islands into Latin America since the early 1970s, but the BPANDEMIC clade remains the dominant strain, making up over 90% of subtype B infections in most countries, with some exceptions.
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Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are widely distributed retroviruses that infect domestic cats (Felis catus). Restriction factors are proteins that have the ability to hamper retroviruses' replication and are part of the conserved mechanisms of anti-viral immunity of mammals. The APOBEC3 protein family is the most studied class of restriction factors; they are cytidine deaminases that generate hypermutations in provirus DNA during reverse transcription, thus causing hypermutations in the viral genome, hindering virus replication.

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The Human Immunodeficiency Virus type 1 protease enzyme (HIV-1 PR) is one of the most important targets of antiretroviral therapy used in the treatment of AIDS patients. The success of protease-inhibitors (PIs), however, is often limited by the emergence of protease mutations that can confer resistance to a specific drug, or even to multiple PIs. In the present study, we used bioinformatics tools to evaluate the impact of the unusual mutations D30V and V32E over the dynamics of the PR-Nelfinavir complex, considering that codons involved in these mutations were previously related to major drug resistance to Nelfinavir.

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  • The study investigated the genetic diversity of HIV-1B in southern Brazil, focusing on two groups from Rio Grande do Sul and one from Santa Catarina.
  • The research found that both B"-GWGR and B-GPGR motifs were present in significant percentages, with variations across different locations and time points.
  • No clear link was found between the V3 signatures and exposure types, but B-GPGR appeared to be more common among heterosexual individuals in Santa Catarina, suggesting a regional pattern in the epidemic.
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Background: The HIV-1 epidemic in Brazil is predominantly driven by subtype B. However, in Brazilian Southern region subtype C prevails and a relatively high AIDS incidence rate is observed. The aim of the present study was to assess the temporal dynamics of HIV-1 subtypes circulating in patients from distinct exposure categories in Southern Brazil.

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Background: Entry inhibitors are a class of antiretroviral (ARV) drugs that prevent HIV replication by blocking viral entry into the host cell. The investigation of naturally occurring mutations associated with entry inhibitors across subtypes is required because genetic differences between HIV-1 variants may influence the emergence of drug resistance. Despite the importance of subtype C, which predominates globally, the majority of studies include only subtype B strains.

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