High circulation of hepatitis E virus (HEV) in pigs from the central region of Argentina without evidence of virus occurrence in pork meat and derived products.

Hepatitis E virus (HEV) is an emerging cause of viral hepatitis and pigs are considered a reservoir for the virus. HEV genotype 3 (HEV-3) has been reported in pigs, environmental matrices, and sporadic human cases in Argentina. We aimed to investigate HEV circulation in pigs from central Argentina and to assess the virus presence in pork meat and food products. Four types of samples obtained or derived from pigs collected in Córdoba province (Argentina) between 2019 and 2022, were tested: 276 serum samples were analyzed for anti-HEV antibody detection; stool (n = 20), pork meat (n = 71), and salami (n = 76) samples were studied for RNA-HEV detection, followed by sequencing and phylogenetic analyses. The positivity rate for anti-HEV antibodies was 80.1% (221/276). Eleven fecal samples (11/20) tested positive for RNA-HEV, from animals under 120 days of age. Three samples could be sequenced, and phylogenetic analyses revealed that they belonged to HEV-3 clade abchijklm, clustering close to strains previously detected in wastewater from Córdoba. None of the muscle meat or salami samples tested positive. A high HEV circulation in pigs was found, showing that these animals may play a significant role in the viral maintenance in the region, becoming a potential risk to the exposed population. Despite not detecting RNA-HEV in pork meat and salami in our study, we cannot rule out the possibility of foodborne transmission in Córdoba province.

Ureaplasma diversum-Ureaplasma sp. alone or concomitantly with Mycoplasma hyopneumoniae in pig lungs with and without pneumonia: A descriptive exploratory study in abattoirs.

Occurrence of Ureaplasma diversum (U. diversum) has been associated with reproductive failures in cattle and detected in pigs with and without pneumonia. However, its role in the porcine respiratory disease complex (PRDC) is unclear. A cross-sectional study was conducted in abattoirs, inspecting 280 pig lungs from eight herds. All the lungs were inspected, processed and classified according to the histopathological analysis. Moreover, bronchoalveolar lavage (BAL) specimens were collected and processed by PCR for detection of U. diversum and Mycoplasma hyopneumoniae (M. hyopneumoniae). Ureaplasma sp.-U. diversum and M. hyopneumoniae were detected in 17.1% and 29.3% of the analyzed BAL specimens, respectively. The concomitant presence of both microorganisms was detected in 12.5% of the inspected lungs. Both agents were found in lungs with and without pneumonia. M. hyopneumoniae was detected in 31.8% of pig lungs with enzootic pneumonia-like lesions, while Ureaplasma sp.-U. diversum was detected in 27.5% of lungs with these lesions. This descriptive exploratory study provides information for future experimental and field-based studies to better define the pathogenic role of this organism within the PRDC.

Ureaplasma diversum and Ureaplasma sp. in nasal cavity of pigs: Distribution among herds and individual frequency based on pooled samples.

The role of Ureaplasma diversum in the porcine respiratory disease complex (PRDC), its circulation among herds and prevalence in live pigs is unknown; thus, the objectives of this study were: to determine the presence of U. diversum in indoor intensive pig herds and to determine the individual frequency of pigs with U. diversum from pooled samples. A cross sectional study was carried out in 16 indoor intensive herds from Córdoba and La Pampa provinces, collecting eight nasal swabs specimens that were further processed by two pools of four specimens each by a PCR targeting a fragment of 16S ribosomal RNA gene. Four PCR products were sequenced and aligned against data bases. U. diversum - Ureaplasma sp. were detected in 56.3% of the analyzed herds, with 16.5% (95% CI 8.2-30.8) of positive pigs. It was concluded that U. diversum - Ureaplasma sp. are present in the nasal cavity of live pigs, being widely distributed among herds.

Síndrome multisistémico de desmejoramiento posdestete (SMDP) en cerdos criados al aire libre en una granja situada en Argentina / Postweaning Multisystemic Wasting Syndrome (PMWS) in pigs reared in an outdoor system in the farm in Argentina

Se realizó un estudio clínico-patológico en cerdos criados al aire libre, estos presentaron signos de desmejoramiento y muerte entre los 40 a 90 días de vida. Durante un periodo determinado se registraronlos índices de mortalidad en las categorías de recría y levante. A un grupo de animales con signos de desmejoramiento se les extrajo sangre y se les realizó la necropsia. Se tomaron muestras de tejidos para la realización de análisis histopatológicos, inmunohistoquímicos, bacteriológicos, parasicológicos y virológicos. Los índices de mortalidad estuvieron incrementados en la primera parte del período estudiado. Los signos clínicos observados fueron: retardo en el crecimiento, pérdida de peso y muerte. A la necropsia se observó palidez de mucosas, ganglios linfáticos megálicos y friables, edema de pericardio y de cavidad abdominal. En pulmón se observó neumonía intersticial. El riñón se mostró con áreas blanquecinas en corteza y edema en pelvis. Las lesiones observadas microscópicamente fueron: depleción linfocitaria en órganos linfoides, infiltración de histiocitos, presencia de células gigantes, cuerpos de inclusión intra citoplasmáticos y necrosis multifocales. Además, tanto las células gigantes, los cuerpos de inclusión y los macrófagos de las áreas foliculares de los tejidos linfoides, se manifestaron como inmunorreactivos en la técnica del complejo abidina biotina (ABC) frente al anticuerpo monoclonal del circovirus porcino tipo II (CVP2). Estos hallazgos confirman la presencia de Síndrome de Multisistémico de Desmejoramiento Posdestete (SMDP) en cerdos criados al aire librecon cuadros clínicos patológicos similares a los descriptos en sistemas confinados.