Hepatitis E virus (HEV) is a global public health concern, causing over 20 million infections annually. It is primarily transmitted via the fecal–oral route, with wild boars and domestic swine as major reservoirs involved in zoonotic transmission. Bahía de Samborombón is an important natural reserve in Argentina characterized by a high population of wild boars, located in a livestock-intensive region near major urban centers. As part of a wild boar control program, 11 sampling campaigns were carried out between 2022 and 2023. Fecal, blood, and liver samples were systematically collected from 80 captured animals for the detection and characterization of HEV through antibody and RNA testing. Serological analysis revealed a positivity rate of 42.4%, whereas RT-qPCR detected HEV RNA in 9.1% of fecal samples and 12.5% of liver samples. From the positive samples, seven viral sequences were recovered using RT-nested PCR, including six from ORF1 and one from ORF2. Phylogenetic analysis clustered these sequences within zoonotic HEV genotype 3, showing a close relationship with human sequences from Buenos Aires and neighboring provinces. This study confirms the presence of HEV in wild boars from Argentina, highlighting the circulation of genotype 3, clade abchijklmno and the associated zoonotic risk.

Morbillivirus canis, commonly named Canine distemper virus (CDV), is a morbillivirus implicated in several signs in the Canidae family. In dogs (Canis lupus familiaris), common signs of infection include conjunctivitis, digital hyperkeratosis and neuropathologies. Even with vaccination, the canine distemper disease persists worldwide so the molecular pathways implicated in the infection processes have been an interesting and promising area in new therapeutic drugs research in recent years. It is known that in the process of virus infection, the endoplasmic reticulum (ER) loses its homeostasis, inducing stress and the subsequent unfolded protein response or UPR in which three ER-trans-membrane proteins are implicated: PERK, IRE1 and ATF6. Moreover, in prolonged ER stress, the apoptosis is induced through the CHOP, as a final step of viral infection. Cell culture and molecular techniques such as RT-qPCR and RT-PCR were used in the present study. We demonstrate the activation in vitro of the three UPR pathways after infection with an attenuated strain of CDV. Also, the implication of a MAPK pathway through the p38 protein and the apoptotic CHOP was demonstrated to contribute to the process of infection. Even more, our study suggested that CDV replication occurs in a PERK-dependent manner.

The perturbation of ER homeostasis by viral infection gives rise to the unfolded protein response (UPR), characterized by the activation of three signaling pathways. PERK, IRE1, and ATF6 have been identified as the primary mediators responsible for restoring homeostasis or leading to apoptosis in response to stress. Alphaarterivirus equid, known as equine arteritis virus (EAV), is a RNA virus with importance in the equine industry that could persist in semen and lead to abortions in pregnant mares. The present article explores the consequences of in vitro infection with the EAV Bucyrus strain on UPR. Employing RT-PCR, qPCR and Western blot, our investigation has revealed the activation of PERK and IRE1α pathways, whilst ATF6 has been suppressed. Furthermore, the p38α MAPK, caspase-12, and CHOP genes were found to be upregulated, demonstrating the induction of apoptosis. Finally, in the inhibition experiments, the PERK pathway was found to be implicated in the modulation of viral replication in the initial phases of infection. Conversely, the IRE1α pathway was identified as the predominant UPR pathway in EAV replication, as evidenced by the complete inhibition of replication observed in these experiments. Consequently, the further exploration of this UPR pathway is necessary to determine whether it can effectively suppress EAV replication.

Los parvovirus pertenecen a un grupo de virus no envueltos, capaces de infectar en una amplia variedad de hospedadores domésticos y silvestres, pudiendo causar diversos cuadros clínicos como fallas reproductivas en cerdos y bovinos, enteritis en caninos y aves de corral, panleucopenia en felinos, hepatitis en equinos, enfermedad respiratoria y cutánea en humanos. Estos virus son mayormente especie-específicos, aunque hay evidencia de transmisión interespecie, especialmente en animales silvestres. Su genoma está compuesto por una cadena lineal de ADN, de aproximadamente 5 kb, cuyas secuencias terminales son complejos palindrómicos en forma de horquilla, compuestos por 120 a 200 bases. Se encuentran ampliamente distribuidos y son muy estables en diversas condiciones ambientales, capaces de permanecer infectivos durante largos períodos. Los hospedadores susceptibles se infectan por contacto directo con individuos infectados o fómites y la infección puede ocasionar cuadros clínicos con signos diversos según la especie afectada. Además, algunos hospedadores desarrollan cuadros subclínicos que pueden eliminar el virus en secreciones y excreciones. Para su diagnóstico se emplean técnicas serológicas y moleculares, siendo la PCR la de mayor sensibilidad y especificidad. El tratamiento para los cuadros causados en animales de compañía se basa en la reversión de los signos mediante fluidoterapia, el uso de antimicrobianos de amplio espectro, antieméticos, antiácidos y protectores de la mucosa gástrica. Además, se han comenzado a utilizar antivirales, inmunomoduladores y probióticos para revertir el cuadro clínico. Por otra parte, no existe tratamiento para los cuadros clínicos en animales de producción. En producción porcina el manejo se basa en la prevención a través de la utilización de vacunas inactivadas y medidas de bioseguridad. En la presente revisión se describirán los diversos cuadros clínicos asociados a parvovirus en especies hospedadoras de interés en medicina veterinaria, y aspectos referentes a su clasificación taxonómica, epidemiología, patogenia, diagnóstico tratamiento y prevención.

The canine distemper virus (CDV) is a morbillivirus implicated in several signs in the Canidae family, in dogs, conjunctivitis, digital hyperkeratosis and neuropathologies are common signs of its infection. Even with the existing vaccination, the canine distemper disease persists worldwide so the molecular pathways implicated in the infection processes has been an interesting and promisor area in the new therapeutic drugs research over recent years. It is known that in the process of virus infection the endoplasmic reticulum organelle lost its homeostasis inducing stress and the subsequence unfolded protein response or UPR in which three ER-trans-membrane proteins are implicated: PERK, IRE1 and ATF6. Moreover, in a prolonged ER stress the apoptosis dead are induced through CHOP protein, as a final step of virus infections. Molecular and cell culture techniques as RT-qPCR and RT-PCR were used in the present study. We demonstrate the activation in vitro of the three UPR pathways after infection with an attenuated strain of CDV. Also, the implication of a MAPK pathway through p38 protein and the apoptotic protein CHOP was funded to participate in all times of infection. Even more, our study suggested that CDV replication occur in a PERK-dependent manner.

La enfermedad de Aujeszky (EA) fue registrada por primera vez en el año 1978 en Argentina y, si bien es endémica en la zona de mayor producción porcina, los casos clínicos han sido esporádicos y con alta frecuencia en establecimientos poco tecnificados. Sin embargo, en 2023, una granja tecnificada de engorde del sudeste de Córdoba, con medidas de bioseguridad controladas y certificada negativa de EA de acuerdo a la normativa de SENASA, presentó un cuadro clínico que comenzó con signos respiratorios. Estos signos aparecieron posteriormente en otras dos granjas de producción intensiva de esta región y 60 días luego de haberse registrado los primeros signos respiratorios, se observaron signos nerviosos en una cuarta granja cercana (unidad productora de lechones). A partir de tejidos se aislaron cepas virales en pulmón y linfonódulo, confirmado y caracterizado molecularmente como Suid Alphaherpesvirus 1. En esta emergencia se comenzó a vacunar con vacuna atenuada gE deleteada. No obstante, varios meses después se registraron nuevamente signos respiratorios en un sitio de engorde cercano. Los análisis moleculares por PCR resultaron positivos a gE, confirmando circulación viral y descartando una reversión vacunal. Las cepas aisladas en este periodo corresponden al genotipo I del virus de Aujeszky, característico de nuestro país y el análisis filogenético demostró su agrupamiento con cepas previamente reportadas, indicando que el virus circula en las granjas de Argentina. El brote ocurrido en esta región podría deberse a deficiencias en las medidas de bioseguridad, sin introducción de nuevas cepas. Este trabajo reporta además el primer aislamiento viral a partir de muestras de pulmón y linfonódulo de animales de engorde con signos respiratorios.