Epitope mapping and a candidate vaccine design from canine distemper virus.

Background: Canine distemper (CD) is a worldwide spread disease that has been described in 12 families of mammals, especially in the Carnivora order, being better studied in domestic canines where vaccination represents the best means of control. CD is controlled by vaccination, but many cases of the disease still occur in vaccinated animals.

Aim: The aim of this work was to study antigen-specific epitopes that can subsidize the development of a new vaccine approach.

Development of a New Multispecies Protein A-Based ELISA for Serodiagnosis of Hepatitis E Infection with Validation in Domestic Swine.

Hepatitis E virus (HEV) infects roughly 20 million people worldwide, causing self-limiting acute hepatic disease that can evolve into a chronic course. HEV-3, HEV-4, and HEV-7 genotypes are zoonotic and transmitted to humans by consuming raw or undercooked meat. Here, we developed an indirect ELISA based on the recombinant HEV-3 capsid and performed a seroprevalence study on domestic swine in northeastern Brazil.

Reverse Genetics of Dengue Virus.

Dengue virus (DENV) is one of the most important and widespread arthropod-borne viruses, causing millions of infections over the years. Considering its epidemiological importance, efforts have been directed towards understanding various aspects of DENV biology, which have been facilitated by the development of different molecular strategies for engineering viral genomes, such as reverse genetics approaches. Reverse genetic systems are a powerful tool for investigating virus-host interaction, for vaccine development, and for high-throughput screening of antiviral compounds.

Uncovering neglected subtypes and zoonotic transmission of Hepatitis E virus (HEV) in Brazil.

Hepatitis E virus (HEV) circulation in humans and swine has been extensively studied in South America over the last two decades. Nevertheless, only 2.1% of reported HEV strains are available as complete genome sequences.

The protein disulfide isomerase inhibitor 3-methyltoxoflavin inhibits Chikungunya virus.

Chikungunya virus (CHIKV) is the etiological agent of chikungunya fever, a (re)emerging arbovirus infection, that causes severe and often persistent arthritis, as well as representing a serious health concern worldwide for which no antivirals are currently available. Despite efforts over the last decade to identify and optimize new inhibitors or to reposition existing drugs, no compound has progressed to clinical trials for CHIKV and current prophylaxis is based on vector control, which has shown limited success in containing the virus. Our efforts to rectify this situation were initiated by screening 36 compounds using a replicon system and ultimately identified the natural product derivative 3-methyltoxoflavin with activity against CHIKV using a cell-based assay (EC 200 nM, SI = 17 in Huh-7 cells).

The Antifungal Itraconazole Is a Potent Inhibitor of Chikungunya Virus Replication.

Chikungunya virus (CHIKV) is the causative agent of chikungunya fever, a disabling disease that can cause long-term severe arthritis. Since the last large CHIKV outbreak in 2015, the reemergence of the virus represents a serious public health concern. The morbidity associated with viral infection emphasizes the need for the development of specific anti-CHIKV drugs.

Characterization of the RNA-dependent RNA polymerase from Chikungunya virus and discovery of a novel ligand as a potential drug candidate.

Chikungunya virus (CHIKV) is the causative agent of Chikungunya fever, an acute febrile and arthritogenic illness with no effective treatments available. The development of effective therapeutic strategies could be significantly accelerated with detailed knowledge of the molecular components behind CHIKV replication. However, drug discovery is hindered by our incomplete understanding of their main components.

Active Circulation of Madariaga Virus, a Member of the Eastern Equine Encephalitis Virus Complex, in Northeast Brazil.

Madariaga virus (MADV) is a member of the eastern equine encephalitis virus (EEEV) complex that circulates in Central and South America. It is a zoonotic, mosquito-borne pathogen, belonging to the family . Disturbances in the natural transmission cycle of this virus result in outbreaks in equines and humans, leading to high case fatality in the former and acute febrile illness or neurological disease in the latter.

Serologic evidence of West Nile virus and Saint Louis encephalitis virus in horses from Southern Brazil.

Flaviviruses as West Nile virus (WNV), Saint Louis encephalitis virus (SLEV), Ilhéus virus (ILHV), and Rocio virus (ROCV) are previously reported in different Brazilian regions, but studies in Southern Brazil are still scarce. To improve the information regarding flaviviruses in Southern Brazil, horse serum samples were analyzed using RT-qPCR and a commercial ELISA-Ab against WNV followed by PRNT. All 1000 samples analyzed by real-time RT-PCR resulted negative.

Reporter Replicons for Antiviral Drug Discovery against Positive Single-Stranded RNA Viruses.

Single-stranded positive RNA ((+) ssRNA) viruses include several important human pathogens. Some members are responsible for large outbreaks, such as Zika virus, West Nile virus, SARS-CoV, and SARS-CoV-2, while others are endemic, causing an enormous global health burden. Since vaccines or specific treatments are not available for most viral infections, the discovery of direct-acting antivirals (DAA) is an urgent need.

A scoping review of Chikungunya virus infection: epidemiology, clinical characteristics, viral co-circulation complications, and control.

Chikungunya fever is a mosquito-borne viral illness characterized by a sudden onset of fever associated with joint pains. It was first described in the 1950s during a Chikungunya virus (CHIKV) outbreak in southern Tanzania and has since (re-) emerged and spread to several other geographical areas, reaching large populations and causing massive epidemics. In recent years, CHIKV has gained considerable attention due to its quick spread to the Caribbean and then in the Americas, with many cases reported between 2014 and 2017.

Viral immunogenicity determines epidemiological fitness in a cohort of DENV-1 infection in Brazil.

The dynamics of dengue virus (DENV) circulation depends on serotype, genotype and lineage replacement and turnover. In São José do Rio Preto, Brazil, we observed that the L6 lineage of DENV-1 (genotype V) remained the dominant circulating lineage even after the introduction of the L1 lineage. We investigated viral fitness and immunogenicity of the L1 and L6 lineages and which factors interfered with the dynamics of DENV epidemics.

Current status, challenges and perspectives in the development of vaccines against yellow fever, dengue, Zika and chikungunya viruses.

Emerging and re-emerging viral infections transmitted by insect vectors (arthopode-borne viruses, arbovirus) are a serious threat to global public health. Among them, yellow fever (YFV), dengue (DENV), chikungunya (CHIKV) and Zika (ZIKV) viruses are particularly important in tropical and subtropical regions. Although vector control is one of the most used prophylactic measures against arboviruses, it often faces obstacles, such as vector diversity, uncontrolled urbanization and increasing resistance to insecticides.

Development and characterization of a packaging cell line for pseudo-infectious yellow fever virus particle generation.

Introduction: Pseudo-infectious yellow fever viral particles (YFV-PIVs) have been used to study vaccines and viral packaging. Here, we report the development of a packaging cell line, which expresses the YFV prM/E proteins.

Methods: HEK293 cells were transfected with YFV prM/E and C (84 nt) genes to generate HEK293-YFV-PrM/E-opt.

Construction and characterization of a recombinant yellow fever virus stably expressing Gaussia luciferase.

Yellow fever is an arthropod-borne viral disease that still poses high public health concerns, despite the availability of an effective vaccine. The development of recombinant viruses is of utmost importance for several types of studies, such as those aimed to dissect virus-host interactions and to search for novel antiviral strategies. Moreover, recombinant viruses expressing reporter genes may greatly facilitate these studies.

Risk Analysis and Occurrence of Hepatitis E Virus (HEV) in Domestic Swine in Northeast Brazil.

Anti-HEV antibodies were detected in animals from abattoir and in farms from northeast Brazil. Our results suggest that HEV is highly disseminated in the swine population and might present a great risk to animal handlers and for consumption of raw or undercooked meat and meat products in northeast Brazil.

Systems Biology Reveals NS4B-Cyclophilin A Interaction: A New Target to Inhibit YFV Replication.

Yellow fever virus (YFV) replication is highly dependent on host cell factors. YFV NS4B is reported to be involved in viral replication and immune evasion. Here interactions between NS4B and human proteins were determined using a GST pull-down assay and analyzed using 1-DE and LC-MS/MS.

Serum cytokine/chemokine profiles in patients with dengue fever (DF) and dengue hemorrhagic fever (FHD) by using protein array.

Background: DENV infection can induce different clinical manifestations varying from mild forms to dengue fever (DF) or the severe hemorrhagic fever (DHF). Several factors are involved in the progression from DF to DHF. No marker is available to predict this progression.

Results of a Zika Virus (ZIKV) Immunoglobulin M-Specific Diagnostic Assay Are Highly Correlated With Detection of Neutralizing Anti-ZIKV Antibodies in Neonates With Congenital Disease.

Background:  Usually, immunoglobulin M (IgM) serologic analysis is not sufficiently specific to confirm Zika virus (ZIKV) infection. However, since IgM does not cross the placenta, it may be a good marker of infection in neonates.

Methods:  We tested blood from 42 mothers and neonates with microcephaly and collected cerebrospinal fluid (CSF) specimens from 30 neonates.

Zika antiviral chemotherapy: identification of drugs and promising starting points for drug discovery from an FDA-approved library.

The recent epidemics of Zika virus (ZIKV) implicated it as the cause of serious and potentially lethal congenital conditions such microcephaly and other central nervous system defects, as well as the development of the Guillain-Barré syndrome in otherwise healthy patients. Recent findings showed that anti-Dengue antibodies are capable of amplifying ZIKV infection by a mechanism similar to antibody-dependent enhancement, increasing the severity of the disease. This scenario becomes potentially catastrophic when the global burden of Dengue and the advent of the newly approved anti-Dengue vaccines in the near future are taken into account.

Use of homologous recombination in yeast to create chimeric bovine viral diarrhea virus cDNA clones.

The open reading frame of a Brazilian bovine viral diarrhea virus (BVDV) strain, IBSP4ncp, was recombined with the untranslated regions of the reference NADL strain by homologous recombination in Saccharomyces cerevisiae, resulting in chimeric full-length cDNA clones of BVDV (chi-NADL/IBSP4ncp#2 and chi-NADL/IBSP4ncp#3). The recombinant clones were successfully recovered, resulting in viable viruses, having the kinetics of replication, focus size, and morphology similar to those of the parental virus, IBSP4ncp. In addition, the chimeric viruses remained stable for at least 10 passages in cell culture, maintaining their replication efficiency unaltered.

In vivo near-infrared fluorescence imaging of Leishmania amazonensis expressing infrared fluorescence protein (iRFP) for real-time monitoring of cutaneous leishmaniasis in mice.

The use of Leishmania amazonensis-infected BALB/c mice is an important model for the study of experimental cutaneous leishmaniasis. Here we report the development of a non-invasive method to directly evaluate and measure parasite burden during the course of the infection, based on the near-infrared fluorescence detection of a recombinant L. amazonensis strain.