Virulence determinants of two foot-and-mouth disease viruses of serotype A exhibiting different pathogenicity in adult mice

CACCIABUE, MARCO; GARCÍA-NÚÑEZ, MARÍA SOLEDAD; MARRERO, RUBÉN; RIEDER, ELIZABETH; CARRILLO, ELISA; GISMONDI, MARÍA INÉS

Les Diablerets

Congreso; Europic2016; 2016

Foot-and-mouth disease virus (FMDV) causes an acute disease of cloven-hoofed animals with devastating consequences. Different models including adult C57 Bl/6J mice have been used to study FMDV biology and host susceptibility to viral infection. In this context, we identified two FMDV viruses of serotype A/Arg/01 (derived from field isolates that circulated in Argentina in 2001) exhibiting differential virulence in adult C57 Bl/6J mice. The non-lethal (NL) variant caused mild signs of disease whereas the lethal (L) variant caused death within 24-48 h, independently of the dose used (102-106 pfu/mice). In this work, we evaluated pathological changes induced by NL and L variants in mice inoculated with 105 pfu virus inoculum and examined serum and various organs at 22 hpi. Severe lesions in the exocrine pancreas were observed (60% and 80% necrosis of acinar cells in NL and L inoculated mice, respectively); multifocal apoptosis was evident in thymus and spleen of inoculated mice. Viral load in serum, pancreas, liver and spleen was significantly higher in FMDV-L inoculated mice (p