Molecular analysis of the NP gene of Italian CDV isolates

摘要

Canine distemper virus (CDV) is a highly contagious pathogen that occurs worldwide, causing a fatal disease in young carnivores. This virus is a member of the genus Morbillivirus in the family Paramixouiridae. The disease has been controlled throughout the world using live attenuated vaccines, but in the last few years an increasing number of distemper cases in vaccinated dogs has been recorded in Italy as well as in other European countries. (Blixenkrone-Moller et al, 1993). Epidemiological, serological and histopatological research suggested that the 'new CDVs' had altered antigenicities and/or different pathogenicities from the old strains (Yoshida et al. 1998). Infections caused by these new viruses may explain the increase of distemper cases in Italy. Analysis of the nucleocapsid protein (NP) gene of wild-type strains indicated a separate cluster from the vaccine strain (Yoshida et al., 1998). The NP protein is the most abundant viral structural protein and has been was demonstrated to influence viral persistence as well as regulatory functions such as transcription and replication (Stettler and Zurbriggen, 1995). In this study we analysed a partial nucleotide sequence of the NP gene of four wild-type CDV strains isolated in Italy.