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Canine parvovirus 2 (CPV-2) is a highly contagious enteric virus that causes high morbidity and mortality, especially in dogs under six months of age. Recovery from this illness is dependent on several factors, including the patient’s prognosis for adequate therapy. The aim of this study was to evaluate the risk factors associated with the death outcome in CPV-2 positive dogs in a case-control study conducted at the Veterinary Hospital of the Universidade Federal de Lavras (HV-UFLA) in Lavras, Minas Gerais, Brazil. Twenty-six dogs with CPV-2 symptoms that arrived at the HV-UFLA between 2017 and 2018 were evaluated for inclusion in the study. Data on medical history, clinical signs, blood count and rapid test of parvovirus and faecal test for polymerase chain reaction (PCR) were collected for all the animals. All the dogs received treatment at the HV-UFLA, and the overall fatality rate due to canine parvovirus was 30.77%. Descriptive analysis and univariate and multivariate statistical analyses (logistic regression) were performed to assess the variables that were possibly associated with an unfavourable prognosis (death). In the univariate and multivariate analyses, Systemic Inflammatory Response Syndrome (SIRS) was observed to be a significant risk factor for an unfavourable prognosis in canine parvovirus, as it increased the risk of death by 12.96 times (95% CI 1.85-133.70; P < 0.01) compared with patients who did not exhibit SIRS. Thus, SIRS was strongly associated with an unfavourable prognosis, suggesting that it can be used as a prognostic indicator for canine parvovirus in veterinary practice. RESUMO: O parvovírus canino 2 (CPV-2) é um vírus entérico altamente contagioso que causa alta morbidade e mortalidade, principalmente em cães com menos de seis meses de idade. A recuperação desta doença é dependente de vários fatores, incluindo a determinação do prognóstico do paciente para terapia adequada. O objetivo deste estudo foi avaliar os fatores de risco associados ao desfecho óbito em cães com CPV-2 em um estudo de caso-controle realizado no Hospital Veterinário da Universidade Federal de Lavras (HV-UFLA), em Lavras, Minas Gerais. Vinte e seis cães com sintomas de CPV-2 que chegaram entre 2017 e 2018 ao HV-UFLA foram avaliados para inclusão no estudo. Dados sobre histórico médico, sinais clínicos, hemograma e teste rápido de parvovirose e fezes para reação em cadeia da polimerase (PCR) foram coletados para todos os animais. Todos os cães receberam tratamento estabelecido pelo HV-UFLA e a taxa geral de letalidade por parvovirose canina foi de 30,77%. Análise descritiva e análise estatística univariada e multivariada (regressão logística) foram utilizadas para avaliar variáveis possivelmente associadas a um prognóstico desfavorável (óbito). Na análise univariada e multivariada, a Síndrome da Resposta Inflamatória Sistêmica (SIRS) foi observada como fator de risco significativo para prognóstico desfavorável na parvovirose canina, pois aumentou 12,96 vezes o risco de morte (95% IC 1,85-133,70; P < 0,01) em comparação com aqueles pacientes que não apresentaram SIRS. Assim, a SIRS foi fortemente associada com um prognóstico desfavorável, sugerindo que pode ser utilizada como indicador prognóstico na parvovirose canina na prática veterinária.

Streptococcus pneumoniae and influenza A virus (IAV) are significant agents of pneumonia cases and severe respiratory infections globally. Secondary bacterial infections, particularly by Streptococcus pneumoniae , are common in IAV-infected individuals, leading to critical outcomes. Despite reducing mortality, pneumococcal vaccines have high production costs and are serotype specific. The emergence of new circulating serotypes has led to the search for new prevention strategies that provide a broad spectrum of protection. In this context, vaccination using antigens present in all serotypes, such as Pneumococcal Surface Protein A (PspA), can offer broad coverage regardless of serotype. Employing the reverse genetics technique, our research group developed a recombinant influenza A H1N1 virus that expresses PspA (Flu-PspA), through the replacement of neuraminidase by PspA. This virus was evaluated as a bivalent vaccine against infections caused by influenza A and S. pneumoniae in mice. Initially, we evaluated the Flu-PspA virus’s ability to infect cells and express PspA in vitro, its capacity to multiply in embryonated chicken eggs, and its safety when inoculated in mice. Subsequently, the protective effect against influenza A and Streptococcus pneumoniae lethal challenge infections in mice was assessed using different immunization protocols. Analysis of the production of antibodies against PspA4 protein and influenza, and the binding capacity of anti-PspA4 antibodies/complement deposition to different strains of S. pneumoniae were also evaluated. Our results demonstrate that the Flu-PspA virus vaccine efficiently induces PspA protein expression in vitro, and that it was able to multiply in embryonated chicken eggs even without exogenous neuraminidase. The Flu-PspA-based bivalent vaccine was demonstrated to be safe, stimulated high titers of anti-PspA and anti-influenza antibodies, and protected mice against homosubtypic and heterosubtypic influenza A and S. pneumoniae challenge. Moreover, an efficient binding of antibodies and complement deposition on the surface of pneumococcal strains ascribes the broad-spectrum vaccine response in vivo. In summary, this innovative approach holds promise for developing a dual-protective vaccine against two major respiratory pathogens.

Bovine leukemia virus (BLV) is a retrovirus that causes lymphoma in cattle worldwide and has also been associated with breast cancer in humans. The mechanism of BLV infection in humans and its implication as a primary cause of cancer in women are not known yet. BLV infection in humans may be caused by the consumption of milk and milk-products or meat from infected animals. Breast cancer incidence rates in Brazil are high, corresponding to 29.5% a year of cancer cases among women. In 2020, an estimated 66,280 new cases of breast cancer are expected, whereas in 2018 breast cancer has led to 17,572 deaths, the highest incidence and lethality among cancers in women in this country that year. BLV infection occurrence ranges from 60 to 95% in dairy herds. In addition, there are some regions, such as the Minas Gerais State, southeastern Brazil, where the population traditionally consume unpasteurized dairy products. Taken together, this study aimed to verify if there is a higher association between breast cancer and the presence of BLV genome in breast tissue samples within this population that consumes raw milk from animals with high rates of BLV infection. A molecular study of two BLV genes was carried out in 88 breast parenchyma samples, between tumors and controls. The amplified fragment was subjected to BLV proviral sequencing and its identity was confirmed using GenBank. BLV proviral genes were amplified from tumor breast parenchyma samples and healthy tissue control samples from women, revealing a 95.9% (47/49) and 59% (23/39) positivity, respectively. Our results show the highest correlation of BLV and human breast cancer found in the world to date within the population of Minas Gerais, Brazil.

Recombinant influenza viruses are promising viral platforms to be used as antigen delivery vectors. To this aim, one of the most promising approaches consists of generating recombinant viruses harboring partially truncated neuraminidase (NA) segments. To date, all studies have pointed to safety and usefulness of this viral platform. However, some aspects of the inflammatory and immune responses triggered by those recombinant viruses and their safety to immunocompromised hosts remained to be elucidated. In the present study, we generated a recombinant influenza virus harboring a truncated NA segment (vNA-Δ) and evaluated the innate and inflammatory responses and the safety of this recombinant virus in wild type or knock-out (KO) mice with impaired innate (Myd88 -/-) or acquired (RAG -/-) immune responses. Infection using truncated neuraminidase influenza virus was harmless regarding lung and systemic inflammatory response in wild type mice and was highly attenuated in KO mice. We also demonstrated that vNA-Δ infection does not induce unbalanced cytokine production that strongly contributes to lung damage in infected mice. In addition, the recombinant influenza virus was able to trigger both local and systemic virus-specific humoral and CD8+ T cellular immune responses which protected immunized mice against the challenge with a lethal dose of homologous A/PR8/34 influenza virus. Taken together, our findings suggest and reinforce the safety of using NA deleted influenza viruses as antigen delivery vectors against human or veterinary pathogens.

In Brazil, at least four lineages of influenza A virus circulate pig population: 2009 H1N1 flu pandemic (pH1N1), human-seasonal origin H3N2, H1N1 and H1N2 (huH1 lineages) viruses. Studies related to the occurrence of swine influenza A virus (SIAV) in Brazilian herds have been detecting an increase of occurrence of huH1 lineages. This study aimed to construct recombinant vaccines against the huH1N1 virus and test the immunogens in a murine model. The virus was constructed by reverse genetics using plasmids encoding the HA and NA sequences from a wild huH1N1 virus isolated from an infected pig. Amplified virus was inactivated, and oil-in-water (OW) and gel polymer (GP) adjuvants were used to formulate the vaccines. C57Bl6 mice received two doses with 3 weeks interval by the intramuscular route. Animals were randomly divided into 8 groups (G1-G8): G1 received OW vaccine and G2 PBS plus OW adjuvant; G3 received GP vaccine and G4 PBS plus GP adjuvant; G5 received the live virus by the intranasal route while G6 only PBS; G7 and G8 did not receive any treatment. Serum samples were collected before vaccination and after the first and second dose. Except for G8, three weeks post boost animals were challenged with a wild huH1N1 virus and observed for weight changes. After infection, bronchoalveolar lavage fluid (BALF) and lungs were collected from animals of each group for viral titers and immunohistochemistry (IHC) analysis, respectively. After booster, vaccinated groups seroconverted and the vaccines induced protection upon challenge. Reverse Genetics technique can be used to produce new and quickly updated swine influenza vaccines which is promising to control the virus in Brazilian herds. Future studies may focus on using the technology to produce multivalent recombinant vaccines against distinct strains of SIAVs circulating in Brazilian pig herds. •At least four lineages of swine influenza virus circulate in Brazilian pig herds.•The circulation of different strains poses challenges to control the disease in the country.•Searching for different vaccination methods with efficient adjuvants is crucial for swine influenza control.•The reverse genetics' technique constitutes an important alternative platform for obtaining safe and effective vaccines.

We detected neutralizing antibodies, viral RNA, and sialic acid receptors for Alphainfluenzavirus influenzae in urban coatis (Nasua nasua) in Brazil, suggesting exposure and susceptibility. We used hemagglutination inhibition, reverse transcription quantitative PCR, and histochemistry for detection. Increased epidemiologic wildlife surveillance would improve influenza A emergency event response.

Psittaciform orthobornaviruses are currently considered to be a major threat to the psittacine bird population worldwide. Parrot bornavirus (PaBV) was identified recently in Brazil and, since then, few studies have been conducted to understand the epidemiology of PaBV in captive psittacine birds. In the present study, natural infections by PaBV in South American parrots were investigated in two breeding facilities: commercial (A) and conservationist (B). Thirty-eight psittacine of 21 different species were presented for postmortem examination. Tissue samples were collected and investigated for the presence of PaBV-RNA using RT-PCR. In addition, clinical information about these birds was used when available. PaBV infection was detected in 73.7% of all birds investigated, indicating a wide dissemination of this virus in both facilities. From birds investigated in aviary A, 66.7% showed clinical signs, 100% had typical lesions of proventricular dilatation disease (PDD), 100% had mild to severe proventricular dilatation and 88.9% were PaBV-positive. In birds from aviary B, 27.6% showed clinical signs, 65.5% had typical lesions of PDD, 62% had mild to severe proventricular dilatation and 69% were PaBV-positive. Neurological disease was observed more frequently than gastrointestinal disease. Sequencing analysis of the matrix gene fragment revealed the occurrence of genotype 4 (PaBV-4) in both places. About 15.8% of birds in this study are threatened species. We discussed the difficulties and challenges for controlling viral spread in these aviaries and implications for South American psittacine conservation. These results emphasize the urgent need to develop a national regulatory and health standard for breeding psittacine birds in the country.

St. Louis encephalitis virus (SLEV) is a causative agent of encephalitis in humans in the Western hemisphere. SLEV is a positive-sense RNA virus that belongs to the Flavivirus genus, which includes West Nile encephalitis virus, Japanese encephalitis virus, Dengue virus and other medically important viruses. Recently, we isolated a SLEV strain from the brain of a horse with neurological signs in the countryside of Minas Gerais, Brazil. The SLEV isolation was confirmed by reverse-transcription RT-PCR and sequencing of the E protein gene. Virus identity was also confirmed by indirect immunofluorescence using commercial antibodies against SLEV. To characterize this newly isolated strain in vivo, serial passages in newborn mice were performed and led to hemorrhagic manifestations associated with recruitment of inflammatory cells into the central nervous system of newborns. In summary this is the first isolation of SLEV from a horse with neurological signs in Brazil.

During these past years, several studies have provided serological evidence regarding the circulation of West Nile virus (WNV) in Brazil. Despite some reports, much is still unknown regarding the genomic diversity and transmission dynamics of this virus in the country. Recently, genomic monitoring activities in horses revealed the circulation of WNV in several Brazilian regions. These findings on the paucity of genomic data reinforce the need for prompt investigation of WNV infection in horses, which may precede human cases of encephalitis in Brazil. Thus, in this study, we retrospectively screened 54 suspicious WNV samples collected between 2017 and 2020 from the spinal cord and brain of horses with encephalitis and generated three new WNV genomes from the Ceará and Bahia states, located in the northeastern region of Brazil. The Bayesian reconstruction revealed that at least two independent introduction events occurred in Brazil. The first introduction event appears to be likely related to the North American outbreak, and was estimated to have occurred in March 2013.The second introduction event appears to have occurred in September 2017 and appears to be likely related to the South American outbreak. Together, our results reinforce the importance of increasing the priority of WNV genomic monitoring in equines with encephalitis in order to track the dispersion of this emerging pathogen through the country.

Surveillance of swine influenza A virus (swIAV) traditionally focuses on respiratory matrices, yet emerging evidence suggests that fecal shedding and secondary environmental contamination may also contribute to viral dissemination. In this study, we collected and analyzed nasal, rectal, environmental, milk, and colostrum samples from naturally infected pigs in a commercial farm in Minas Gerais, Brazil. IAV RNA was detected in 25% of samples, including 42% from asymptomatic animals, with nasal swabs showing higher detection rates (30%) than rectal swabs (20%), though rectal Ct values were consistently higher, indicative of lower viral loads. We successfully isolated viable viruses from feces and effluent samples. Whole-genome sequencing revealed co-circulation of enzootic pH1N1 clade #2 (HA) and pN1 clade #4 (NA), alongside human-origin H3N2 sequences clustering within clade 3C.2a1b.2a.2a.1, and N2 segments related to pre-3C human lineages from 2001 to 2002. Phylogenetic and p-distance analyses support both recent reverse zoonosis and historical transmission events. Detection of complete HA/NA sequences from rectal swabs and treated effluent further emphasizes the surveillance value of non-respiratory matrices. The integration of respiratory and fecal/environmental sampling appears important to achieve more comprehensive IAV monitoring in swine herds and may have significant implications for One Health strategies in Brazil and beyond.