TY - JOUR T1 - Pathogenesis of encephalomyocarditis experimental infection in young piglets: a potential animal model to study viral myocarditis. JF - Vet Res Y1 - 2006 A1 - Gelmetti, Daniela A1 - Meroni, Alessandra A1 - Brocchi, Emiliana A1 - F. Koenen A1 - Cammarata, Giorgio KW - Animals KW - Cardiovirus Infections KW - Disease Models, Animal KW - Encephalomyocarditis virus KW - immunohistochemistry KW - Macrophages KW - Myocarditis KW - Myocardium KW - Organ Specificity KW - Palatine Tonsil KW - Random Allocation KW - Swine KW - Swine Diseases AB -

The pathogenesis of encephalomyocarditis (EMC) due to the EMC virus (EMCV) was studied in 24 piglets oro-nasally infected with the field isolate B279/95. Two pigs were kept as negative controls and were euthanised at hour 0. The remaining 24 were euthanised every 6 h up to 78-h post infection (hpi). Virus isolation, histological examination and EMCV immunodetection were performed on the spleen, intestine, pancreas, liver, kidneys, heart, lungs, lymph nodes, tonsils and brain. EMCV was isolated at 6-hpi from the intestine and lymph nodes and at 12-hpi from the heart. From 6 to 12-hpi, scattered degenerate myocardiocytes were immunolabelled. Subsequently, myocarditis developed and progressively worsened. Immunopositive reaction in tonsil macrophages, observed in the early stage of infection (6-hpi), suggests that tonsils are the portal of entry, and by mean of wandering macrophages the EMC virus is then distributed through the body. Afterwards, EMCV-B279/95 replicates intensively in the cytoplasm of myocardiocytes and the acute myocarditis is strictly related to the tropism of these cells. Four pigs died spontaneously. In three animals no post mortem lesions or virus were isolated/detected, although all of them showed mild myocarditis. The experimental infection with EMCV B279/95 indicates: (i) the experimental protocol mimics the individual variability observed in natural disease, (ii) tonsils are the portal of entry of infection and the heart is the target organ, (iii) EMCV provides a valuable animal model for comparative studies on progressive viral myocarditis.

VL - 37 CP - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/16336922?dopt=Abstract M3 - 10.1051/vetres:2005041 ER -