Porcine circovirus (PCV) is a small, circular, non-enveloped, single-stranded DNA virus belonging to the family Circoviridae, genus Circovirus. The genome encodes two major open reading frames (ORFs): ORF1 encodes a replication-associated protein (rep), while ORF2 encodes the viral capsid (cap) protein that determines the antigenic characteristics of the virus (Mankertz et al., 2004). Until recently, only two species of circovirus had been reported in pigs (Allan & Ellis, 2000). Porcine circovirus 1 (PCV1) was first identified as a cell culture contaminant and is considered non-pathogenic in pigs.In contrast, PCV2 is a ubiquitous, economically significant pathogen

Since Aujeszky`s disease (pseudorabies), which is caused by Suid herpesvirus type 1 (SuHV-1), was first notified in Argentina in 1978, many SuHV-1 strains have been isolated from swine. However, this disease can affect other vertebrates, such as dogs (secondary hosts), and lead to fatal neurological disease. The objective of the current work is to report the first isolation and molecular characterization of SuHV-1 from a dead domestic dog from Santa Fe Province (Argentina), which had had nervous signs compatible with pseudorabies. Samples of brain and trigeminal ganglia from this dog were obtained and fixed in formol for histopathology, and virology studies were conducted after cell disruption. Supernatants of both samples were inoculated onto RK13 cells and, after 72 h, DNA was extracted with phenol-chloroform. Purified DNA was cut with a restriction enzyme and subjected to agarose gel and an aliquot was used to amplify the gD and gC genes by PCR. The gC sequence was compared with other public sequences. The strain isolated from the dog was similar to other Argentinean swine strains.

Porcine parvovirus (PPV) is one of many pathogens responsible for reproductive failure in pregnant sows. Several studies have reported the appearance of new PPV strains that differ from previous isolates both genetically and antigenically. Thus, the protective effects of commercially inactivated vaccines could not be complete. In South America, the information about PPV is limited. Thus, the aim of the present study was to detect and characterize the PPV strains present in 131 mummies or stillbirths from normal deliveries in sows from a commercial swine farm of Argentina that uses the commercial vaccine. PCR results showed that 17/131 were positive to PPV. Ten of these viruses were isolated and sequenced. All viruses were related to the PPV1 sequence (NADL-2), maintaining the amino acid differences in positions 436 (S-P) and 565 (R-K). This study is the first to report the isolation of PPV in Argentina and the results suggest that PPV can cross the placenta even in vaccinated sows, thus affecting some of the fetuses and being able to cause fetal death in sows without reproductive failure. The results also suggest that vaccination only reduces clinical signs and reproductive disorders and may thus not be a perfect tool to manage PPV infection. This study provides information that needs to be studied in depth to improve strategies to prevent and control PPV infection in swine farms.

La pandemia de la COVID-19 planteó el rápido diseño y aprobación excepcional de diversos métodos de diagnóstico. En la unidad de diagnóstico COVID- 19 de la FCV-UNLP, se realizó el diagnóstico molecular de la presencia de SARS-CoV-2 en 1114 hisopados de pacientes derivados por el Ministerio de Salud de la Provincia de Buenos Aires. Las muestras de ARN fueron purificadas en cabina de seguridad y se analizaron mediante real time RT-PCR con el kit GeneFinder™ para tres targets virales (N, E y RdRp). De 1110 muestras con reacción al control interno, 458 (41,2%) fueron reactivas, 26,9% a tres targets virales, 4,2% a dos y cerca del 10% a uno (principalmente N). El porcentaje de positividad fue similar en el tiempo, aunque la cantidad fue mayor en julio (781 muestras; 315 reactivas) respecto a junio (333 muestras; 143 reactivas). Las muestras de Berisso, Ensenada y La Plata presentaron un porcentaje de positividad significativamente menor al de los demás municipios (27,6% vs. 60,7%). Las muestras de pacientes con tres o más signos relevantes presentaron una mayor positividad (55,6%) y menor reactividad a un único target. Es necesaria la validación interlaboratorios y la estandarización de los métodos para brindar resultados confiables y reproducibles.

No abstract

El objetivo de este trabajo fue analizar la performance de 3 kits comerciales de real time RT-PCR para la detección de SARS-CoV-2 en muestras de hisopados nasofaríngeos, mediante el criterio de mayoría. Se seleccionaron 100 muestras de ARN informadas en el SISA como detectables (n=50) o no detectables (n=50) con el GeneFinder-COVID-19 Plus RealAmp, que fueron posteriormente analizadas mediante el BGI-Real-Time Fluorescent for Detecting SARS-CoV-2 y el DisCoVery-SARS-CoV-2 RT-PCR. Los niveles de concordancia fueron de buenos a excelentes; Genefinder y DisCoVery presentaron sensibilidad del 100%, mientras que BGI presentó una sensibilidad menor al 90%. Se analizaron los productos de 10 muestras discordantes o dudosas mediante electroforesis en gel de agarosa. Se confirmaron 3 muestras como falsos negativos del BGI y 5 muestras detectables al DisCoVery se presumen como verdaderos positivos. El uso de los kits DisCoVery y GeneFinder™ se presenta como una excelente opción, con buenos valores de sensibilidad y especificidad.

Background: Aujeszky’s disease is mainly a swine disease, still endemic worldwide. It can infect other mammalians, including human beings, and it is usually fatal with nervous symptoms. Since the disease was detected in 1988 in Argentina, many outbreaks have been reported, involving both feral swine and dogs. Aim: At present, in Argentina, PRV cases are sporadically reported, however clinical cases are informed. The purpose of this study is to obtain information about the seroprevalence of PRV in wild boar and to isolate and characterize PRV from clinical samples. Methods: From 2018 to 2019, 78 wild boars serum samples from Bahía de Samborombón natural reserve were analyzed for antibodies to PRV using a virus neutralization test. Clinical samples from 17 pigs, 2 wild boar, one dog and 1 cat were collected from 2013 to 2019 for viral isolation and detecting the presence of the gD gene by PCR. For sequence analysis, the gC partial gene was amplified. Results: Five strains were isolated from the dog, cat and swine samples. The new PRV strains identified were confirmed by BLAST analysis, which revealed between 99.74 to 100% of similarity to the NIA-3 strain and phylogenetic analysis of the partial gene encoding the gC protein revealed that the PRV strains have divided into two main clades, clade 1 and clade 2. Conclusion: This report informed that most new cases of PRV were detected in the central regions of Argentina, where the pig production is concentrated. The study in Bahía de Samborombón revealed a high percentage of detection but the sampling is not representative of that of the rest of the country. Therefore, a systematic sampling effort of wild boar throughout the country should be included in the national program control. Although in Argentina only the inactivated Bartha vaccine is allowed, recombination risk should not be ignored if attenuated vaccines are incorporated into the National control plan. The two strains, one from the cat and one from the dog sample, are directly related to infected swine. The information about clinical cases and molecular characterization of new strains are important for a better understanding of the dynamics of PRV and to promote preventive measures.

Una partícula viral de aproximadamente 120 nm ha modificado totalmente lo que sucede en nuestro mundo de 12.000 km de diámetro. La primera epidemia del coronavirus del síndrome respiratorio agudo grave (SARS), y luego la del síndrome respiratorio de Oriente Medio (MERS), alertaron del potencial de transmisión entre especies de esta familia viral. Sin embargo, no fue hasta su tercer gran salto con la pandemia del SARS-CoV-2 que el foco de toda la comunidad científica se centró en ellos. Existen diversos saltos interespecies reportados en medicina veterinaria que no son más que intentos de los coronavirus de perfeccionar su potencial de transmisión para llegar a más de 7 mil millones de huéspedes en quienes replicar. Este artículo describe las características morfológicas y genéticas de los coronavirus, su particular mecanismo de replicación y cómo este influye en su diseminación. Del mismo modo, se describen signos clínicos, lesiones, variantes antigénicas y control mediante vacunación de los principales coronavirus asociados a diferentes especies animales, con un especial énfasis en los antecedentes reportados sobre coronavirus en América Latina.