Exploring the epidemiology of lapine Rotaviruses: evidence for spreading of Rotaviruses displaying the newly-recognised P[22] VP4 gene allele in Italy

An epidemiological survey was carried out to investigate the distribution of the VP7 and VP4 antigenic specificities of lapine rotaviruses (LRV) in Italy. Rotaviruses were identified in rabbitries from different geographical regions of Northern and Southern Italy. The VP7 and VP4 specificities of the Italian LRV strains were determined by either PCR genotyping or sequence analysis. Almost all the strains (14 out of 16) were characterised as P[22],G3, confirming the presence of viruses resembling the newlyrecognised P[22] LRVs in Italian rabbitries. The P[22] VP4s detected were about 87.3 to 91.5% identical at the amino acid level to the prototype P[22] LRV strains (160/01, 229/01 and 308/01), identified in 2001 in Italy. Only 1 strain was characterised as P[14],G3 and 1 sample was a mixed infection of P[14],G3 and P[22],G3 LRVs. These data are suggestive of an almost complete replacement of the P[14] allele by the P[22] in Italian rabbitries.