Detection and characterization of porcine sapoviruses from asymptomatic animals in Irish farms

P.J. Collins , V. Martella , C. Buonavoglia , H. O'Shea

Caliciviruses are an important cause of gastroenteritis in humans and animals. Molecular analysis of the polymerase and capsid genes of porcine caliciviruses, sapoviruses (SaVs) and noroviruses (NoVs), has demonstrated a broad range of genetic diversity but information on their epidemiology and pathogenic role in pigs is limited. In this study, 292 faecal samples were obtained from 4-5 to 8-9 week old asymptomatic pigs from 4 porcine herds in Ireland during 2005-2007 and were screened by RT-PCR using calicivirus-specific primers. Only 7 samples from 2 porcine herds tested positive for porcine calicivirus. By sequence analysis of the partial RNA-dependent RNA polymerase (RdRp) fragment, 6 samples from one such herd were closely related to each other (>98% nucleotide identity) and were characterised as genogroup (GG) III (Cowden-like) porcine SaVs. These viruses demonstrated an amino acid (aa) identity of 81.3-98.6% to GGIII SaVs. Conversely, one calicivirus strain, 9/07/Ire (identified from a different herd in 2007), was distantly related to GIII SaVs and displayed 94.6-98.6% aa identity to rare K7-like porcine caliciviruses, representatives of a potential novel SaV genogroup (GGVII), described previously in Japan and the USA. Circulation of SaVs in asymptomatic animals might be a mechanism of virus persistence in porcine populations and should be considered with respect to understanding the epidemiology of these viruses in porcine herds.

Mots clés: Medicine

P.J. Collins, V. Martella, C. Buonavoglia, H. O'Shea. Detection and characterization of porcine sapoviruses from asymptomatic animals in Irish farms. Veterinary Microbiology, 2009, 139 (1-2), pp.176. ⟨10.1016/j.vetmic.2009.05.013⟩. ⟨hal-00520665⟩