ABSTRACT
BACKGROUND: In 2014, a notification of porcine transmissible gastroenteritis virus (TGEV) was made by the National Services of Animal Health of Argentina (SENASA) to the World Organization of Animal Health (OIE). The notification was based on a serological diagnosis in a small farm with a morbidity rate of 2.3% without enteric clinical signs. In order to determine if TGEV was circulating before the official report, a retrospective study on cases of neonatal diarrhea was performed. The selection criteria was a sudden increase in mortality in 1- to 21-day-old piglets with watery diarrhea that did not respond to antibiotics. Based on these criteria, three clinical cases were identified during 2010-2015. RESULTS: All animals that were evaluated presented histological lesions consistent with enteric viral infection. The feces and ultrathin sections of intestine that were evaluated by electron microscopy confirmed the presence of round particles of approximately 80 nm in size and characterized by finely granular electrodense nucleoids consistent with complete particles of coronavirus. The presence of the TGEV antigen was confirmed by monoclonal specific immunohistochemistry, and final confirmation of a metabolically-active virus was performed by in situ hybridization to detect a TGE mRNA encoding spike protein. All sections evaluated in this case were negative for PEDV and rotavirus A. CONCLUSIONS: This is the first case series describing neonatal mortality with etiological confirmation of TGEV in Argentina. The clinical diagnosis of TGEV infections in endemic regions is challenging due to the epidemiological distribution and coinfection with other enteric pathogens that mask the clinical presentation.
Subject(s)
Gastroenteritis, Transmissible, of Swine/diagnosis , Swine Diseases/diagnosis , Transmissible gastroenteritis virus/isolation & purification , Animals , Argentina/epidemiology , Female , Gastroenteritis, Transmissible, of Swine/epidemiology , Male , Retrospective Studies , Swine , Swine Diseases/epidemiologyABSTRACT
Porcine circovirus type 2 (PCV-2) has been associated with syndromes grouped by the term porcine circovirus associated diseases (PCVAD). The PCV-2 isolates have been grouped into two major groups or genotypes according to their nucleotide sequence of whole genomes and/or ORF-2: PCV-2b, which have, in turn, been subdivided into three clusters (1A-1C), and PCV-2a, which has been subdivided into five clusters (2A-2E). In the present study, we obtained 16 sequences of PCV-2 from different farms from 2003 to 2008, from animals with confirmatory diagnosis of PCVAD. Since results showed an identity of 99.8% among them, they were grouped within a common cluster 1A-B. This preliminary study suggests a stable circulation of PCV-2b among the Argentinean pig population.
ABSTRACT
Objetivos. Investigar la presencia Erysipelothrix rhusiopathiae en cerdos de las categorías crecimiento y engorde con lesiones sistémicas no cutáneas compatibles con las de mal rojo (MR) provenientes de dos granjas, situadas en la provincia de Buenos Aires, Argentina. Materiales y Métodos. Muestras de tonsilas, corazón (endocardio), bazo, riñón y líquido articular con lesiones compatibles con las del mal rojo se inocularon en caldo ESB y se repicaron en medio sólido MBA. A partir de colonias similares a las del género Erisipelothrix, se realizaron tinción de Gram y pruebas fisiológicas y bioquímicas. La identificación serológica se llevó a cabo por la prueba de inmunodifusión doble en gel de agarosa enfrentando antígenos extractados de las cepas en estudio contra sueros hiperinmunes de los 28 serotipos de referencia de E. rhusiopathiae.Resultados. Se aisló E. rhusiopathiae de dos cerdos a partir de tonsilas (sin lesiones aparentes), bazo (con esplenomegalia), endocardio valvular (con lesiones de endocarditis) y exudado articular (no purulento). En otro animal sólo se lo aisló de exudado articular. Las tres cepas de E. rhusiopathiae correspondieron al serotipo 10. El aislamiento de E. rhusiopathiae se dificultó debido al crecimiento de bacterias de los géneros Lactobacillus spp y Enterococcus spp que enmascararon o compitieron en el desarrollo de las colonias. Discusión. El E. rhusiopathiae serotipo 10 es raramente aislado de cerdos y no se lo ha asociado a cuadros clínicos de erisipela. El aislamiento E. rhusiopathiae serotipo 10 de lesiones sistémicas no cutáneas compatibles con las del MR del cerdo, constituye la primera referencia de la infección del cerdo por E. rhusiopathiae en el país así como de la patogenicidad de dicho serotipo.