Susceptibility of equid herpesvirus 3 field isolates to antiviral compounds

Inst.de VirologíaFil: Vissani, Aldana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Zabal, Osvaldo Alfredo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología: Argentina. Universidad del Salvador. Escuela de Veterinaria. Cátedra de Enfermedades Infecciosas; ArgentinaFil: Tordoya, Maria Silvia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología: ArgentinaFil: Thiry, Etienne. University of Liege. Faculty of Veterinary Medicine. FARAH Center. Department of Infectious and Parasitic Diseases. Veterinary Virology and Animal Viral Diseases; BélgicaFil: Barrandeguy, Maria Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; Argentina. Universidad del Salvador. Escuela de Veterinaria. Cátedra de Enfermedades Infecciosas; Argentin

Multifocal outbreak of equine influenza in vaccinated horses in Argentina in 2018: Epidemiological aspects and molecular characterisation of the involved virus strains

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.Fil: Olguin Perglione, Cecilia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Vissani, María Aldana. Universidad del Salvador; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alamos, Florencia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Tordoya, Maria Silvia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Barrandeguy, M.. Universidad del Salvador; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentin

On-site detection of equid alphaherpesvirus 3 in perineal and genital swabs of mares and stallions

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%; κ = 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.Fil: Vissani, María Aldana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Tordoya, Maria Silvia. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Tsai, Y.-L.. GeneReach; Estados UnidosFil: Lee, P.-Y.A.. GeneReach; Estados UnidosFil: Shen, Y.-H.. GeneReach; Estados UnidosFil: Lee, F.-C.. GeneReach; Estados UnidosFil: Wang, H.-T.T.. GeneReach; Estados UnidosFil: Parreño, Gladys Viviana. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barrandeguy, María Edith. Instituto Nacional de Tecnología Agropecuaria; Argentina. Universidad del Salvador. Escuela de Veterinaria; Argentin

Viral infections in horses in Argentina : an overview based on laboratory results

Inst.de VirologíaFil: Vissani, Aldana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Olguin Perglione, Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Miño, Samuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Carossino, Mariano. University of Kentucky. Department of Veterinary Science. Maxwell H. Gluck Equine Research Center; Estados Unidos. Universidad del Salvador. Escuela de Veterinaria; Argentina.Fil: Micheloud, Juan Francisco. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta. Grupo de Trabajo de Patología, Epidemiología e Investigación Diagnóstica. Área de Sanidad Animal; ArgentinaFil: Russo, S. Servicio Nacional de Sanidad y Calidad Agroalimentaria. Departamento de Rabia y Enfermedades de Pequeños Animales, Virología Dilab-SENASA; ArgentinaFil: Tordoya, Maria Silvia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología: ArgentinaFil: Becerra, María Luciana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Zabal, Osvaldo Alfredo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología: Argentina. Universidad del Salvador. Escuela de Veterinaria. Cátedra de Enfermedades Infecciosas; ArgentinaFil: Barrandeguy, Maria Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; Argentina. Universidad del Salvador. Escuela de Veterinaria. Cátedra de Enfermedades Infecciosas; Argentin

In vitro comparison of acyclovir, ganciclovir and cidofovir against equid alphaherpesvirus 3 and evaluation of their efficacy against six field isolates = Comparación in vitro de aciclovir, ganciclovir y cidofovir contra alfa-herpesvirus equino 3 y evaluación de la eficacia de los mismos frente a 6 aislamientos de campo del virus

Equid alphaherpesvirus 3 (EHV3) is the etiological agent of equine coital exanthema (ECE), which is a venereal, highly contagious disease, characterized by the formation of papules, vesicles, pustules and ulcers on the external genitalia of mares and stallions. EHV3 remains in a latent state after a successful infection and there are latently infected animals in which the virus is reactivated and generally re-excreted subclinically. There are no available vaccines for this condition and prevention is based on the clinical examination of mares prior to mating, which allows to segregate those showing clinical signs. As this approach does not eliminate the risk of contagion in stallions from subclinically infected mares, there is a need for a specific EHV3 treatment. Nowadays, there exist various antiviral compounds of proven effectiveness for other alphaherpesviruses affecting humans and animals. The aim of the present study was to compare the efficacy of three antiviral compounds, acyclovir, ganciclovir and cidofovir against EHV3 in vitro, and to assess their efficacy against six EHV3 Argentinian field isolates. To determine the efficacy of these compounds in vitro, three parameters were analyzed: reduction of plaque number, reduction of plaque size and reduction of viral production. Additionally, the effectiveness of the three compounds at an optimum concentration previously determined in this study was investigated for the EHV3 field isolates. Based on our results, ganciclovir was the most potent antiviral compound to reduce EHV3 replication in vitro and may thus be a valuable candidate for treatment and prevention of ECE in mares and stallions.El alfa-herpesvirus equino 3 (EHV3) es el agente etiológico del exantema coital equino (ECE), enfermedad venérea, altamente contagiosa y caracterizada por la aparición de pápulas, vesículas, pústulas y úlceras en los genitales externos de yeguas y padrillos. Luego de la primo-infección, el EHV3 se mantiene en el animal en un estado de latencia a partir del cual puede reactivar y excretarse, generalmente de manera subclínica. No existen vacunas, por lo que la prevención se basa en la detección de las lesiones clínicas previo al servicio, y la segregación de estos animales. Sin embargo, este abordaje no previene la infección del padrillo por parte de yeguas que excretan el virus de manera subclínica, y por lo tanto existe la necesidad de un tratamiento específico contra el EHV3. En la actualidad, existen varios compuestos antivirales de probada eficacia contra herpesvirus humanos y veterinarios. El objetivo de este trabajo es comparar la eficacia de 3 compuestos antivirales, aciclovir, ganciclovir y cidofovir, contra EHV3 in vitro, y evaluar la eficacia de los mismos contra 6 cepas de campo argentinas de EHV3. Para determinar la eficacia de los compuestos in vitro se evaluaron 3 parámetros: reducción del número de placas de lisis, reducción del tamaño de placas de lisis y reducción de la producción de virus. Adicionalmente, la efectividad de los compuestos en una concentración óptima, previamente determinada en este estudio, fue determinada para 6 cepas de campo argentinas de EHV3. De acuerdo con los resultados obtenidos, ganciclovir fue el compuesto más potente en reducir la replicación del EHV3 in vitro, y por lo tanto podría considerarse un potencial candidato para el tratamiento y la prevención del ECE en yeguas y padrillos.Instituto de VirologíaFil: Vissani, Aldana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Zabal, Osvaldo Alfredo. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; Argentina. Universidad del Salvador. Escuela de Veterinaria. Cátedra de Enfermedades Infecciosas; ArgentinaFil: Tordoya, Maria Silvia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Parreño, Viviana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Thiry, Etienne. University of Liege. Faculty of Veterinary Medicine. Veterinary Virology and Animal Viral Diseases and UREAR. Department of Infectious and Parasitic Diseases; BélgicaFil: Barrandeguy, Maria Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; Argentina. Universidad del Salvador. Escuela de Veterinaria. Cátedra de Enfermedades Infecciosas; Argentin

On-site detection of equid alphaherpesvirus 3 in perineal and genital swabs of mares and stallions

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%; κ = 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.Instituto de VirologíaFil: Vissani, Aldana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Tordoya, Maria Silvia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Tsai, Yun-Long. GeneReach USA, Lexington; Estados UnidosFil: Lee, Pei-Yu Alison. GeneReach USA, Lexington; Estados UnidosFil: Shen, Yu-Han. GeneReach USA, Lexington; Estados UnidosFil: Lee, Fu-Chun. GeneReach USA, Lexington; Estados UnidosFil: Wang, Hwa-Tang Thomas. GeneReach USA, Lexington; Estados UnidosFil: Parreño, Viviana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; ArgentinaFil: Barrandeguy, Maria Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología; Argentina. Universidad del Salvador. Escuela de Veterinaria. Cátedra de Enfermedades Infecciosas; Argentin