Epidemiologia molecolare di piccoli virus a DNA a singolo filamento

Carnivore protoparvovirus 1 and Canine circovirus are two small viruses with a genome formed by one molecule of single-strand DNA; this feature gives these viruses a great tendency to evolve. While the pathogenic role of Carnivore protoparvovirus 1 variants is well known, that of Canine circovirus (CanineCV) remains still unclear. In the first study, the presence of DNA of feline panleukemia virus (FPV) and canine parvovirus 2 (CPV-2) in the buffy-coat of a population of cats was investigated. Then the humoral immunity against parvovirus was evaluated in the positive subjects. The identified viruses were successively molecularly characterized. DNA of FPV and CPV-2 was identified in buffy-coats of healthy cats, despite antibody titers considered protective; this suggests that cats can play an important role in the epidemiology of parvovirus infections. In the second study a molecular assay able to detect the circoviruses circulating both in domestic and wild canids was developed. Successively, the Real-Time PCR assay previously developed was used to determine the prevalence of the CanineCV infections in dogs with parvovirosis; the clinical and clinical-pathological data was then compared between subjects affected both by CanineCV and CPV-2 and subjects affected by CPV-2 only. No statistical differences were found between the two groups, and the effective pathogenic role of CPV-2 is still unclear. The same Real-Time PCR assay was also used to investigate the circulation of CanineCV in a population of Italian red foxes; the genomic nucleotide sequences of the identified viruses were then characterized and phylogenetically analyzed. This study identified, for the first time in Italy, a red fox infected by a CanineCV with genetic characteristics more similar to those circulating in dogs (compared to those circulating in the foxes), suggesting a possible transmission of the virus between the two host species.