RESUMO
Genetic influence on pork quality exists between breeds and within a breed. The variation is caused by a large set of genes, and pork quality traits have a multifactorial background. Research into the genetics of meat quality found causative mutations associated with marked effects on pig meat value. This study aimed to investigate the segregation of meat quality-related SNPs and compare their diversity and genetics in commercial and Creole pigs from different farms in the North-West of Argentina. A screen for SNPs in RYR1, PRKAG3, CAST, and SOX6 candidate genes and the differentiation of their genotypes by PCR-RFLP was conducted. All genes were characterized by a high level of polymorphism and heterozygosity, and populations showed no differences in the genetic structure for the analyzed SNPs. These results highlighted the role of pig genotypes as a source of basic variability potentially affecting processed meat products and fresh meat.
RESUMO
BACKGROUND: Equine influenza is an important cause of respiratory disease of horses worldwide. The equine influenza virus (EIV) undergoes antigenic drift through the accumulation of amino acid substitutions in the viral proteins, which may lead to vaccine breakdown. OBJECTIVES: To describe the epidemiological findings and the molecular characteristics of the EIV detected during the multifocal outbreak that occurred in Argentina between March and July 2018 and evidence a vaccine breakdown. STUDY DESIGN: Observational, descriptive study. METHODS: Virus was detected in nasopharyngeal swabs using real-time reverse transcriptase PCR (RT-PCR). Nucleotide and deduced amino acid sequences of the haemagglutinin (HA) and neuraminidase (NA) genes were obtained from EIV positive nasopharyngeal swabs, and phylogenetic analysis was undertaken. Amino acid sequences were compared against the current World Organisation for Animal Health (OIE)-recommended Florida clade 1 vaccine strain and strain components of vaccines used in Argentina. Serum samples were tested using haemagglutination inhibition test. RESULTS: Equine influenza virus infection was confirmed using real-time RT-PCR and serological testing. The phylogenetic analysis of the HA and NA genes revealed that all the EIV identified during the outbreak belong to the H3N8 subtype, Florida clade 1. Multiple amino acid changes, some of them at antigenic sites, were observed in the circulating virus when compared with the strains included in the most commonly used vaccine in Argentina. Seventy-six percent of the affected horses had been vaccinated with this vaccine, suggesting the occurrence of vaccine breakdown. MAIN LIMITATIONS: The study does not include antigenic characterisation and full genome sequencing of Argentinian strains, that could provide additional information. CONCLUSIONS: The occurrence of this multifocal equine influenza outbreak in regularly vaccinated horses is a field evidence of vaccine breakdown, reinforcing the necessity of keeping vaccine strains updated according to OIE recommendations. It also underlines the importance of the implementation of appropriate quarantine measures and restriction of horse movement in the face of disease.
Assuntos
Doenças dos Cavalos , Vírus da Influenza A Subtipo H3N8 , Infecções por Orthomyxoviridae , Animais , Argentina , Surtos de Doenças , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/virologia , Cavalos , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/veterinária , FilogeniaRESUMO
Equine coital exanthema (ECE) is an infectious, venereally transmitted muco-cutaneous disease affecting mares and stallions, caused by equid alphaherpesvirus 3 (EHV3). Diagnostic tools for rapid identification of EHV3 are of primary importance to diminish the risk of EHV3 dissemination at the time of breeding. In the last years, it has been shown that the performance of the insulated-isothermal polymerase chain reaction (iiPCR) is comparable to virus isolation, nested PCR and real-time PCR (qPCR) in detecting pathogens of various animal species. Analytical sensitivity and specificity of the iiPCR were compared with a qPCR, using a plasmid containing the target region of the EHV3 glycoprotein G gene and an Argentinian EHV3 isolate (E/9283/07 C3A). In order to evaluate the diagnostic performance of the iiPCR, nucleic acids of 85 perineal and genital swabs (PGS) of mares and stallions were extracted by tacoTM mini and tested by both techniques. EHV3 was detected in 46 and 45 of the 85 PGS by the iiPCR and qPCR, respectively. There was almost perfect agreement between the two diagnostic methods (98.82%; 95% CI: 95.03-100%; κâ¯=â¯0.98). The iiPCR had a limit of detection of 95.00% at 6 genome equivalents per reaction and a detection endpoint for viral DNA comparable to that of the qPCR, and did not react with six non-targeted equine pathogens. The iiPCR represents a sensitive and specific method for the rapid on-site diagnosis of EHV3 infection. Its routinely implementation in breeding facilities, and artificial insemination and embryo transfer centers, will contribute to prevent the dissemination of this venereal, highly contagious disease in horses.
Assuntos
Genitália/virologia , Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 3/isolamento & purificação , Doenças dos Cavalos/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Períneo/virologia , Reação em Cadeia da Polimerase/métodos , Animais , Infecções por Herpesviridae/diagnóstico , Doenças dos Cavalos/virologia , Cavalos , Testes Imediatos , Sensibilidade e EspecificidadeRESUMO
Group A rotaviruses (RVA) are important infectious agents associated with diarrhea in the young of several animal species including foals. Currently, a variety of diagnosis methods are commercially available, like ELISA, latex agglutination and immunochromatographic assays. These commercial tests are mainly designed for the detection of human RVA; its applicability in veterinary diagnosis has been poorly studied. The aim of this study was to compare the sensitivity and specificity of two commercial diagnostic kits, Pathfinder™ Rotavirus and FASTest Rota® strip, with an in-house KERI ELISA, for the detection of equine RVA. A total of 172 stool samples from Thoroughbred foals with diarrhea were analyzed. The presence of equine RVA in samples in which only one of the three methods showed positive results was confirmed by RT-PCR. A sample was considered "true positive" when RVA was detected by at least two of the methods, and "true negative" when it tested negative by the three assays. Following these criteria, 50 samples were found positive and 122 were found negative, and were handled as reference population for the assay validation. Pathfinder™ Rotavirus assay showed 32% sensitivity and 97% specificity, FASTest Rota® strip, 92% sensitivity and 97% specificity, and KERI ELISA, 76% sensitivity and 93% specificity. Pathfinder™ Rotavirus showed 77%, FASTest Rota® strip 95%, and KERI ELISA 88% accuracy to correctly classify the samples as equine RVA positive or negative. Pathfinder failed specifically to detect equine RVA G3P12I6 genotype; such performance might be related to the specificity of the monoclonal antibody included in this kit. According to our results, differences among VP6 genotypes could influence the sensitivity to detect equine RVA in foal feces, and thus assay validation of diagnostic kits for each species is necessary. In conclusion, FASTest Rota® strip is more suitable than ELISA Pathfinder™ Rotavirus for the screening of rotavirus infection in foals. The KERI ELISA showed an acceptable performance, and could be considered a proper economic alternative for equine RVA diagnosis.
Assuntos
Testes Diagnósticos de Rotina/métodos , Fezes/virologia , Imunoensaio/métodos , Infecções por Rotavirus/veterinária , Rotavirus/isolamento & purificação , Medicina Veterinária/métodos , Animais , Cavalos , Dados de Sequência Molecular , RNA Viral/genética , Infecções por Rotavirus/virologia , Sensibilidade e Especificidade , Análise de Sequência de DNARESUMO
Equine group A rotavirus (RVA) strains are the most important cause of gastroenteritis in equine neonates and foals worldwide, and G3P[12] and G14P[12] are epidemiologically the most important genotypes. The genotype constellation of an unusual Argentinean G3P[3] RVA strain (RVA/Horse-wt/E3198/2008/G3P[3]) detected in fecal samples of a diarrheic foal in 2008 was shown to be G3-P[3]-I3-R3-C3-M3-A9-N3-T3-E3-H6. Each of these genotypes has been found typically in feline and canine RVA strains, and the genotype constellation is reminiscent to those of Cat97-like RVA strains. However, the phylogenetic analyses revealed only a distant relationship between E3198 and known feline, canine and feline/canine-like human RVA strains. Surprisingly, a rather close relationship was found between E3198 and simian RVA strains RVA/Simian-tc/USA/RRV/1975/G3P[3] for at least 5 gene segments. RRV is believed to be a reassortant between a bovine-like RVA strain and a RVA strains distantly related to feline/canine RVA strains. These analyses indicate that E3198 is unlikely to be of equine origin, and most likely represents a RVA interspecies transmitted virus, possibly in combination with one or more reassortments, from a feline, canine or related host species to a horse. Further studies are in progress to evaluate if this strain was a single interspecies transmission event, or if this strain started to circulate in the equine population.
Assuntos
Genoma Viral , Doenças dos Cavalos/virologia , Infecções por Rotavirus/veterinária , Infecções por Rotavirus/virologia , Rotavirus/classificação , Animais , Sequência de Bases , Gatos , Bovinos , Cães , Fezes/virologia , Gastroenterite/veterinária , Gastroenterite/virologia , Genótipo , Cavalos , Humanos , Dados de Sequência Molecular , Filogenia , Rotavirus/genética , Infecções por Rotavirus/genéticaRESUMO
Equine coital exanthema (ECE), caused by equid herpesvirus 3 (EHV-3), has been recognized as an economically significant venereal disease for years. However, no infection models on the natural host have been established. In order to set up an experimental infection protocol, seronegative and seropositive mares were topically inoculated in the perineal region with 4 × 10(6)TCID(50)/ml of EHV-3. Clinical signs were then evaluated by means of a designed scoring system, and body temperature was recorded daily. Virological, and serological studies were also performed. Typical ECE lesions, with clinical scores of 90, 92, 160 and 172, were observed in the four seronegative animals. Only mild ECE lesions were observed in the two seropositive mares, being the clinical scores 53 and 41. Both groups of mares shed the virus, but the duration of virus shedding was shorter and its intensity was lower in seropositive mares than in seronegative ones. Moreover, EHV-3 antibody response was detected in both seronegative and seropositive mares after experimental infection and re-infection, being more moderate in seropositive ones. As a conclusion, EHV-3 infection of mares was experimentally achieved in a reproducible manner. The typical lesions of ECE were observed after topical EHV-3 infection in seronegative mares, in association with virus excretion and neutralizing antibody kinetics.
Assuntos
Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 3/fisiologia , Doenças dos Cavalos/imunologia , Doenças dos Cavalos/patologia , Infecções Sexualmente Transmissíveis/veterinária , Animais , Anticorpos Antivirais/sangue , Formação de Anticorpos , Sequência de Bases , Feminino , Genótipo , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/patologia , Infecções por Herpesviridae/virologia , Doenças dos Cavalos/virologia , Cavalos , Dados de Sequência Molecular , Alinhamento de Sequência , Infecções Sexualmente Transmissíveis/imunologia , Infecções Sexualmente Transmissíveis/patologia , Infecções Sexualmente Transmissíveis/virologia , Fatores de Tempo , Proteínas do Envelope Viral/genética , Eliminação de Partículas ViraisRESUMO
The temporary disruption of reproductive activities due to equine coital exanthema (ECE), caused by equid herpesvirus 3 (EHV-3), at thoroughbred breeding facilities and embryo transfer centres, has an appreciable economic impact. The aim of the present study was to estimate the prevalence of excretion of EHV-3 in mares without clinical symptoms under field conditions and the re-excretion patterns of the virus in two seropositive (presumably latently infected) mares maintained in isolation for 11 mo. The EHV-3 virus was detected in perineal-vaginal swabs by real time PCR in 14 (6%) of 220 thoroughbred mares without clinical symptoms at the time of breeding. In the two isolated mares, re-excretion of EHV-3 was demonstrated on two occasions, 3 mo apart (each for a 3 d interval) in one mare, and on only 1 d in the other mare. Antibodies against EHV-3 were identified by seroneutralization in 105 (48%) of the thoroughbred mares, and during the entire period in the two isolated mares. Therefore, the present study provided evidence of EHV-3 shedders in a healthy mare population under both field and isolation conditions. Furthermore, at least two periods of spontaneous EHV-3 reactivation and re-excretion in the presence of serum antibodies occurred in one mare in an 11 mo interval. These findings could assist in the design and implementation of measures to minimize the spread of EHV-3 and control ECE outbreaks.
Assuntos
Infecções por Herpesviridae/veterinária , Herpesvirus Equídeo 3/isolamento & purificação , Doenças dos Cavalos/virologia , Eliminação de Partículas Virais , Animais , Infecções por Herpesviridae/virologia , Herpesvirus Equídeo 3/fisiologia , Doenças dos Cavalos/imunologia , Cavalos , Periodicidade , Ativação ViralRESUMO
The purpose of this study was to develop and evaluate a simple immunochromatographic lateral flow (ICLF) test for specific detection of Equine infectious anemia virus (EIAV) antibodies in equine sera. Viral recombinant p26 capsid protein (rp26) was used as the capture protein in the test line and as the detector reagent conjugated to colloidal gold. The performance of rp26-ICLF was evaluated, and the results obtained were compared with a commercially available agar gel immunodiffusion (AGID) test used as a standard of comparison according to international guidelines. The values obtained for comparative diagnostic sensitivity (98.3%), diagnostic specificity (87.4%) and concordance (92.4%) were similar to those reported for other ICLF tests for animal infectious diseases. Very good repeatability and reproducibility, as well as a total agreement with blind previous results from three proficiency test panels, were obtained, thus indicating that rp26-ICLF is a precise test. The end point of the twofold serial dilution of serum samples was the same as, and even better than, the AGID test, thus demonstrating the same analytical sensitivity as that of the reference method for EIA diagnosis. No cross-reactivity was observed when serum samples from horses with other infectious diseases were analyzed. rp26-ICLF proved to be a precise and rapid test suitable for field screening in veterinary practice, since minimal equipment and operator expertise are required. However, further research should be carried out to increase the level of sensitivity.
Assuntos
Anticorpos Antivirais/sangue , Anemia Infecciosa Equina/diagnóstico , Vírus da Anemia Infecciosa Equina/imunologia , Animais , Proteínas do Capsídeo , Reações Cruzadas , Coloide de Ouro , Cavalos , Imunoensaio/métodos , Vírus da Anemia Infecciosa Equina/isolamento & purificação , Proteínas Recombinantes , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Coloração e Rotulagem/métodosAssuntos
Surtos de Doenças/veterinária , Herpesvirus Equídeo 3/isolamento & purificação , Doenças dos Cavalos/epidemiologia , Rinite/veterinária , Animais , Argentina/epidemiologia , Endoscópios/microbiologia , Endoscópios/veterinária , Contaminação de Equipamentos , Feminino , Herpesvirus Equídeo 3/genética , Doenças dos Cavalos/transmissão , Doenças dos Cavalos/virologia , Cavalos , Masculino , Rinite/virologiaRESUMO
The bovine viral diarrhea virus (BVDV) infection control should be based on elimination of persistently infected animals and on immunization through vaccination, to prevent fetal infection. However, the efficacy of inactivated BVDV vaccines is variable due to its low immunogenicity. This study evaluated the humoral immune response against homologous and heterologous strains of 7 inactivated BVDV vaccines, in bovines and two experimental models (ovine and guinea pig) which might be used to test candidate vaccines. Vaccines formulated with BVDV Singer, Oregon, NADL, and multivalent, induced seroconversion in the three animal models studied, reaching antibody titres higher than 2. Vaccine containing 125C -genotype 2- only induced a low antibody response in ovine, while VS-115 NCP vaccine was not immunogenic. Furthermore, bovine sera at 60 dpv presented homologous as well as heterologous antibody response, indicating a high degree of cross-reactivity among the strains studied. However, when bovine sera were tested against the Argentine field strain 00-693, they showed the lowest levels of cross-reactivity, suggesting the need of continued surveillance to identify and characterize emerging field BVDV strains. Finally, optimal correlations between bovine-ovine and bovine-guinea pig models were observed, indicating that two alternative species could replace bovines when testing the immunogenicity of BVDV candidate vaccines.