Farvet (Peru)

Infectious Bronchitis Virus (IBV) is a major threat to the poultry industry worldwide, causing significant economic losses. While the virus’s genetic structure is well understood, the specific strains circulating in Bolivia have remained uncharacterized until now. This study aimed to identify and characterize new IBV strains in Bolivia. Tissue samples from broilers exhibiting clinical signs of Infectious Bronchitis were screened to detect IBV using real-time RT-PCR (RT-qPCR). Positive samples with low cycle threshold (Ct) values were selected for sequencing the full S1 gene. Of the 12 samples analyzed, 10 were determined to be positive for IBV. However, only four samples yielded sufficient genetic material for sequencing and subsequent phylogenetic analysis. The results revealed the presence of GI-1 and GI-23 lineages, both belonging to genotype I (GI). The GI-1 lineage showed >99% sequence identity to the H120 and Massachusetts vaccine strains, suggesting a close relationship. In contrast, the GI-23 lineage clustered with other IBV strains, showing a distinct subclade that is genetically distant from Brazilian strains. No evidence of recombination was found. Furthermore, amino acid substitution analysis identified specific mutations in the S1 subunit, particularly in the hypervariable regions 1, 2, and 3. These mutations could potentially alter the virus’s antigenicity, leading to reduced vaccine efficacy. The findings of this study highlight the importance of continued and broad genomic surveillance of circulating IBV strains and the need to improve vaccination strategies in Bolivia.

Genome sequencing of highly virulent Salmonella enterica subsp. enterica serovar Javiana strain FARPER-220 (ST-1674) isolated from broiler chickens in Peru revealed multiple virulence factors, antibiotic resistance genes, and invasion-related subcategories. The results provide insights into the potential importance of this strain in causing infections in various animals.

BackgroundNewcastle disease (ND) is a major threat to the poultry industry, leading to significant economic losses. The current ND vaccines, usually based on active or attenuated strains, are only partially effective and can cause adverse effects post-vaccination. Therefore, the development of safer and more efficient vaccines is necessary. Epitopes represent the antigenic portion of the pathogen and their identification and use for immunization could lead to safer and more effective vaccines. However, the prediction of protective epitopes for a pathogen is a major challenge, especially taking into account the immune system of the target species.ResultsIn this study, we utilized an artificial intelligence algorithm to predict ND virus (NDV) peptides that exhibit high affinity to the chicken MHC-I complex. We selected the peptides that are conserved across different NDV genotypes and absent in the chicken proteome. From the filtered peptides, we synthesized the five peptides with the highest affinities for the L, HN, and F proteins of NDV. We evaluated these peptides in-vitro for their ability to elicit cell-mediated immunity, which was measured by the lymphocyte proliferation in spleen cells of chickens previously immunized with NDV.ConclusionsOur study identified five peptides with high affinity to MHC-I that have the potential to serve as protective epitopes and could be utilized for the development of multi-epitope NDV vaccines. This approach can provide a safer and more efficient method for NDV immunization.

ABSTRACTSurveillance helps us identify and monitor strains with zoonotic potential. A tracheal swab from a pelican on a Peruvian beach was H5N1 positive (clade 2.3.4.4b) using Oxford Nanopore’s MinION platform. The near-complete genome sequence of strain VFAR-140 will aid us in understanding avian influenza epidemiology and spread.

Although typical Newcastle disease virus (NDV) vaccines can prevent mortality, they are not effective in preventing viral shedding. To overcome this, genotype-matched vaccines have been proposed. To date, this approach has never been tested against genotype XII strains. In this study, we generated and assessed the protection against genotype XII challenge of two chimeric NDV vaccine strains (rLS1-XII-1 and rLS1-XII-2). The rLS1-XII-1 virus has the complete fusion protein (F) and the hemagglutinin-neuraminidase (HN) open reading frames replaced with those from genotype XII strain NDV/peacock/Peru/2011 (PP2011) in a recombinant LaSota (rLS1) backbone. In rLS1-XII-2 virus, cytoplasmic tails of F and HN proteins were restored to those of rLS1. In vitro evaluation showed that rLS1-XII-2 and the parental rLS1 strains replicate at higher efficiencies than rLS1-XII-1. In the first vaccine/challenge experiment, SPF chickens vaccinated with rLS1-XII-1 virus showed only 71.3% protection, whereas, rLS1 and rLS1-XII-2 vaccinated chickens were fully protected. In a second experiment, both rLS1-XII-2 and the commercial vaccine strain LaSota induced 100% protection. However, rLS1-XII-2 virus significantly reduced viral shedding, both in the number of shedding birds and in quantity of shed virus. In conclusion, we have developed a vaccine candidate capable of fully protecting chickens against genotype XII challenges. Furthermore, we have shown the importance of cytoplasmic tails in virus replication and vaccine competence.

ABSTRACTWe report here the first genome sequence of infectious laryngotracheitis virus isolated in Peru from tracheal tissues of layer chickens. The genome showed 99.98% identity to the J2 strain genome sequence. Single nucleotide polymorphisms were detected in five gene-coding sequences related to vaccine development, virus attachment, and viral immune evasion.

BackgroundNewcastle disease is one of the most important infectious diseases of poultry, caused by Newcastle disease virus (NDV). This virus is distributed worldwide and it can cause severe economic losses in the poultry industry due to recurring outbreaks in vaccinated and unvaccinated flocks. Protection against NDV in chickens has been associated with development of humoral response. Although hemagglutination inhibition (HI) assay and ELISA do not corroborate the presence of neutralizing antibodies (nAbs); they are used to measure protection and immune response against NDV.MethodsIn this study, we established a system to recover a recombinant NDV (rLS1) from a cloned cDNA, which is able to accept exogenous genes in desired positions. An enhanced green fluorescent protein (eGFP) gene was engineered in the first position of the NDV genome and we generated a recombinant NDV carrying eGFP. This NDV- eGFP reporter virus was used to develop an eGFP-based neutralization test (eGFP-NT), in which nAbs titers were expressed as the reciprocal of the highest dilution that expressed the eGFP.ResultsThe eGFP-NT gave conclusive results in 24 h without using any additional staining procedure. A total of 57 serum samples were assayed by conventional neutralization (NT) and eGFP-NT. Additionally, HI and a commercial ELISA kit were evaluated with the same set of samples. Although HI (R2 = 0.816) and ELISA (R2 = 0.791) showed substantial correlation with conventional NT, eGFP-NT showed higher correlation (R2 = 0.994), indicating that eGFP-NT is more accurate method to quantify nAbs.ConclusionsOverall, the neutralization test developed here is a simple, rapid and reliable method for quantitation of NDV specific nAbs. It is suitable for vaccine studies and diagnostics.

Avaliou-se o efeito da adição de bagaço de caju desidratado (BCD), durante o pós-parto, em 41 ovelhas, alojadas com suas crias em baias, onde recebiam, à vontade, 75% de capim-elefante + 25% de concentrado (DI; n=17), ou 50% de BCD + 25% de capim-elefante + 25% de concentrado (DII; n=24). Cinquenta dias pós-parto, o estro foi sincronizado, e as ovelhas submetidas à monta natural. O grupo DI perdeu mais peso (P<0,05), e o consumo de proteína bruta e de fibra em detergente neutro foi maior nesse grupo (P<0,001). A inclusão de BCD na dieta II induziu ao aumento do consumo de matéria seca, extrato etéreo e fibra em detergente ácido (P<0,001) e redução significativa das concentrações de colesterol, lipídios totais, albumina e proteína total (P<0,001). Não houve diferença entre os grupos (P>0,05) no tempo de retorno do primeiro corpo lúteo funcional, na resposta à sincronização do estro e nas taxas de gestação e prolificidade. A inclusão de 50% de BCD amenizou as perdas de peso, foi bem consumida e não influenciou nas respostas reprodutivas após a sincronização do estro.

O objetivo do presente estudo foi determinar os efeitos do sistema de alojamento, em gaiolas individuais ou baias coletivas, durante a metade da gestação, no desempenho de fêmeas suínas e de suas leitegadas. Após terem sido inseminadas com 220 dias de idade, em média, as leitoas foram alojadas em gaiolas, até aproximadamente 55 dias de gestação, quando parte delas permaneceram em gaiolas (n=94) e outra parte foi transferida para baias coletivas (n=113), com seis fêmeas/baia. Não houve efeito dos tratamentos na taxa de parto ajustada (P>0,05). As leitoas que permaneceram em gaiolas foram mais pesadas aos 110 dias de gestação e após o parto (P0,05), quando comparadas às transferidas para baias coletivas. Os sistemas de alojamento não afetaram o total de leitões nascidos e nascidos vivos, o peso médio dos leitões ao nascer e o intervalo desmame-estro (P>0,05). No entanto, verificou-se que as fêmeas alojadas em baias consumiram mais ração na lactação (P0.05). However, it was observed that group-housed females showed higher intake during lactation (P