Reverse Vaccinology approach for antigen candidates prioritization to develop a vaccine against a poultry pathogen

PosterAvibacterium paragallinarum (AvP) is the causative agent of infectious coryza, an acute disease that affects the upper respiratory system of chickens. This Gram-negative pathogen is widely distributed in poultry production systems all over the world, causing significant economic losses. Despite vaccination being the main form of prevention, commercially available vaccines show incomplete protection against strains not included in the formulation.EEA BalcarceFil: Felici, María Esperanza. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina.Fil: Felici, María Esperanza. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Huberman, Yosef Daniel. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Maletto, Belkys. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina.Fil: Maletto, Belkys. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Quiroga, Rodrigo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina.Fil: Quiroga, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Pathogenicity of avibacterium paragallinarum strains from Peru and the selection of candidate strains for an inactivated vaccine

Worldwide, Avibacterium paragallinarum is the aetiological agent of infectious coryza in poultry. Vaccines are the best means of control, helping reduce clinical signs and colonization of this bacterium. Most vaccines are based on international reference strains, or, lately, regional strains, but, generally, without any information regarding their virulence. The characterization of the pathogenicity of 24 Av. paragallinarum strains of the three Page serogroups, including four variant strains of serogroup B, all isolated from infectious coryza outbreaks in Peru, was performed. After experimental inoculation into the infraorbital sinuses, information regarding their capacity to induce infectious coryza typical clinical signs, spreading, and colonization was recorded. Furthermore, after intraperitoneal inoculation, septicaemia and death were registered. Differences among strains in these parameters were observed, even within strains from the same serogroup. Finally, the four most pathogenic strains, one from each serogroup, were chosen to formulate an experimental vaccine that was tested successfully against homologous challenges in reducing clinical signs and colonization in vaccinated birds compared to unvaccinated ones. This is the first time that Av. paragallinarum strains from Peru were studied thoroughly for their virulence in a search for improving vaccine formulation.EEA BalcarceFil: Caballero Garcia, Melanie. Quimtia. Research and Development; Perú.Fil: Mendoza Espinoza, Alfredo. Quimtia. Research and Development; Perú.Fil: Ascanio, Silvia. Quimtia. Research and Development; Perú.Fil: Chero, Paula. Quimtia. Research and Development; Perú.Fil: Rojas, Rober. Quimtia. Research and Development; Perú.Fil: Huberman, Yosef Daniel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina

Evaluación de la eficiencia <i>in vitro</i> de extractos vegetales polifenoles sobre el crecimiento de <i>Salmonella enteritidis, Salmonella typhimurium, S. gallinarum</i> y <i>Escherichia coli</i> aisladas de aves

A nivel mundial, cepas patógenas de Salmonella sp. y Escherichia coli causan enfermedades zoonóticas de importancia económica en humanos y animales. Las infecciones humanas generalmente conducen a enfermedades gastrointestinales auto-limitadas; sin embargo, en algunos casos, una infección puede volverse grave debido a la creciente aparición de cepas resistentes a múltiples antibióticos. En la búsqueda de compuestos naturales con propiedades antimicrobianas y antioxidantes para controlar algunos de estos patógenos, el uso de polifenoles, acidificantes, aceites esenciales y polisacáridos es cada vez más común. El empleo de estos compuestos contribuye al reemplazo de los productos químicos, a mejorar la salud pública y aporta a la salud de las aves como también en los índices de producción. En este trabajo se evaluó, mediante pruebas CIM, el efecto de tres productos comerciales sobre el crecimiento in vitro de seis cepas de Salmonella sp. y dos cepas de E. coli aisladas de aves: AES (bisulfato de sodio, polifenoles y pectinascítricas), Bioquina plus (polifenoles y aceite de eucalipto) y Bioquina MN (polifenoles hidrolizados, pectinas cítricas y aceite esencial).Trabajo publicado en Cagliada, Maria del Pilar Lilia y Galosi, Cecilia Mónica (comps.). I Congreso de Microbiología Veterinaria. Libro de resúmenes. La Plata: Facultad de Ciencias Veterinarias, 2021.Facultad de Ciencias Veterinaria

Estandarización de un protocolo para obtención de inóculo inactivado de adenovirus aviar serotipos 4 y 8b en células LMH = Protocol standardization for obtaining inactivated inoculum of avian adenovirus serotypes 4 and 8b in LMH cells

Adenovirus aviar tipo 1 (FAdV) es considerado un patógeno de importancia para la industria avícola. Los serotipos 4 (FAdV-4) y 8b (FAdV-8b) son responsables de hepatitis por cuerpos de inclusión (IBH) y síndrome de hidropericardio (HHS) en pollos y son prevalentes en el Perú. El objetivo del presente trabajo fue establecer un protocolo estandarizado de obtención de inóculos virales inactivados de FAdV-4 y FAdV-8b producidos en células de hepatoma de pollo (LMH). Para ello, células LMH al 70 % de confluencia,crecidas en medio DMEM con 10 % de suero fetal bovino, fueron infectadas con FAdV-4 o FAdV-8b para evaluar el valor de multiplicidad de infección (MOI) y tiempo de cosecha óptimos. Luego, se realizó la producción de 1L de ambos serotipos considerando un MOI de 10 y tiempo de cosecha de 96 h post-infección (hpi). Seguidamente, ambas cosechas virales fueron clarificadas y concentradas mediante ultrafiltración tangencial (UFT) en membrana de 100kDa e inactivadas con 30mM de etilenimina binaria (BEI) a 37°C por 18 h. La pérdida de infectividad fue corroborada por el cálculo de dosis infecciosa del 50 % de cultivo de células (TCID50). Nuestros resultados mostraron que con un MOI de 10 y cosecha de 96 hpi se alcanzó el mayor título viral (> 1x108 TCID50/mL). Además, se mostró que la UFT permitió concentrar 10 veces la cantidad de virus con una recuperación del 91% y que la inactivación con BEI fue eficiente. Los inóculos inactivados obtenidos pueden ser utilizados en la formulación de una vacuna para prevenir IBH y HHS en pollos de forma segura.Avian adenovirus type 1 (FAdV) is considered an important pathogen for the poultry industry. Serotypes 4 (FAdV4) and 8b (FAdV-8b) are responsible for Inclusion Body Hepatitis (IBH) and Hydropericardium Syndrome (HHS) in chickens and are prevalent in Perú. The objective of this work was to establish a standardized protocol for obtaining inactivated viral inoculum of FAdV-4 and FAdV-8b produced in chicken hepatoma (LMH) cells. For this, LMH cells at 70 % confluence, grown in DMEM medium with 10 % fetal bovine serum, were infected with FAdV-4 or FAdV-8b to evaluate the optimal multiplicity of infection (MOI) value and harvest time. Then, the production of 1L of both serotypes was carried out considering an MOI of 10 and a harvest time of 96 h postinfection (hpi). Next, both viral harvests were clarified and concentrated by tangential ultrafiltration (UFT) on a 100kDa membrane and inactivated with 30mM Binary Ethyleneimine (BEI) at 37°C for 18 h. Loss of infectivity was corroborated by calculating the 50 % cell culture infectious dose (TCID50). Our results showed that with an MOI of 10 and a harvest time of 96 hpi, the highest viral titer was reached (> 1x108 TCID50/mL). In addition, it was shown that UFT allowed concentrating 10 times the amount of virus with a 91% recovery rate and that inactivation with BEI was efficient. The inactivated inoculum obtained can be used in the formulation of a vaccine to safely prevent IBH and HHS in chickens.EEA BalcarceFil: Flores Santos, Juan Carlos. Quimtia, Desarrollo e investigación; Perú.Fil: Quispe, Juana. Quimtia, Desarrollo e investigación; Perú.Fil: Huberman, Yosef Daniel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Mendoza Espinoza, Alfredo. Quimtia, Desarrollo e investigación; Perú.Fil: Caballero García, Melani. Quimtia, Desarrollo e investigación; Perú

Eficacia de polifenoles acidificados aditivados derivados de ácido galacturónico en aves infectados con Salmonella Gallinarum

PosterLa tifosis aviar causada por Salmonella Gallinarum es una de las enfermedades más importantes de las aves de corral. En Argentina, esta enfermedad se considera como endémica. Se debe aplicar medidas de bioseguridad para la prevención ya que los índices de mortalidad pueden alcanzar el 100%.EEA BalcarceFil: Huberman, Yosef Daniel. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Trevisi, D.E. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Malena, Rosana Claudia. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Lomónaco, Jorgelina. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Nievas, Paula Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Gulle, Abel. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Gulle, Cristian. Instituto Nacional de Tecnología Agropecuaria (INTA) Estación Experimental Agropecuaria Balcarce; Argentina

The efficacy of a trivalent inactivated salmonella vaccine combined with the live s. gallinarum 9R vaccine in young layers after experimental infections with s. enteritidis, s. typhimurium, and s. infantis

Worldwide, poultry infections by Salmonella are the cause of significant economic losses, not only due to reduced production (due to fowl typhoid disease), but also considering the efforts and control measures that must be constantly applied, especially due to zoonotic serovars. Poultry is a common reservoir of Salmonella and its transmission into the food chain is a risk for humans. The vaccination of layers plays an important role in the overall efforts to prevent Salmonella infections. An inactivated trivalent vaccine was prepared with S. Enteritidis, S. Typhimurium, and S. Infantis strains. Infection trials were performed to evaluate the efficacy of three vaccination schedules using inactivated and live S. Gallinarum 9R vaccines. For this purpose, at week 5 of life, one subcutaneous dose of live S. Gallinarum 9R vaccine (1–5 × 107 CFU) was given to Groups 1 and 2. At weeks 8 and 11 of life, chickens were also vaccinated with one (Group 1) or two (Groups 2 and 3) intramuscular doses of the inactivated oil-adjuvant trivalent vaccine (1 × 108 CFU/dose of each antigen). Group 4 consisted of chickens that remained unvaccinated (control). At week 14 of life, the efficacy of the vaccination plans was evaluated in three separate inoculation trials with S. Enteritidis, S. Typhimurium, or S. Infantis. After vaccination with the inactivated vaccine, homologous antibody production was observed, and after challenge, a significant reduction in the faecal shedding, invasion, and colonization of S. Typhimurium and S. Infantis was achieved by all vaccination schedules, while the vaccination with at least one dose of the live S. Gallinarum 9R vaccine was necessary to obtain such a significant protection against S. Enteritidis infection.EEA BalcarceFil: Huberman, Yosef Daniel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Caballero Garcia, Melanie. Quimtia. Research and Development; Perú.Fil: Rojas, Rober. Quimtia. Research and Development; Perú.Fil: Ascanio, Silvia. Quimtia. Research and Development; Perú.Fil: Olmos, Leandro Hipólito. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Malena, Rosana Claudia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Lomónaco, Jorgelina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Nievas, Paula Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Chero, Paula. Quimtia. Research and Development; Perú.Fil: Lévano Gracía, Julio. Quimtia. Research and Development; Perú.Fil: Mendoza Espinoza, Alfredo. Quimtia. Research and Development; Perú

Evaluation of different live Salmonella enteritidis vaccine schedules administered during layer hen rearing to reduce excretion, organ colonization, and egg contamination

Salmonellosis caused by Salmonella Enteritidis is a widespread zoonosis and poultry products are an important source of infection. This study was carried out to evaluate the protection of different vaccination schedules in layers using a live commercial attenuated Salmonella Enteritidis vaccine based on strain Sm24/Rif12/Ssq (AviPro® Salmonella Vac E, ELANCO) during rearing and egg production. Three hundred and fifty Salmonella-free chickens were distributed into 7 vaccinated groups and 1 unvaccinated group. Different vaccination schedules were performed combining either 1, 2, or 3 oral gavage doses. Chickens from Group A, B, and C were vaccinated once, either at the first day, at 7 or 16 wk old, respectively. Chickens from Group D were vaccinated twice—at the first day and 7 wk old. Chickens from Group E were vaccinated twice—at the first day and 16 wk old. Chickens from Group F were vaccinated twice—at 7 and 16 wk old. Chickens from Group G were vaccinated 3 times, following the manufacturer's recommendation: at the first day, 7 and 16 wk old. Chickens from Group H remained unvaccinated. Five challenge trials numbered 1 to 5 were carried out at 8, 12, 16, 29, and 55 wk old, respectively. After challenge, chickens were sampled by cloacal swabbing and, after euthanasia, livers, ovaries, spleens, and cecal contents were cultured to isolate S. Enteritidis. Additionally, eggs were collected after challenge and cultured to isolate S.Enteritidis on egg shells (Trials 4 and 5). Protection against experimental infection with a virulent nalidixic acid resistant S. Enteritidis strain K285/94, was evaluated by measuring reduction of excretion, colonization, invasion into organs, eggshell contamination, and egg production. The live S. Enteritidis vaccine protected the hens by reducing S. Enteritidis excretion, isolation from organs, and egg contamination. Higher protection throughout laying period was afforded after administration of three vaccine doses during rearing period.EEA BalcarceFil: Huberman, Yosef Daniel. INTA, Estación Experimental Agropecuaria Balcarce, Argentina.Fil: Velilla, Alejandra Vanesa. INTA, Estación Experimental Agropecuaria Balcarce, Argentina.Fil: Terzolo, Horacio Raúl. INTA, Estación Experimental Agropecuaria Balcarce, Argentina