Genetic complexity and multiple infections with more Parvovirus species in naturally infected cats

Mara Battilani,Massimo Giunti,Andrea Balboni,Alessandra Scagliarini,Santino Prosperi,Martina Ustulin

doi:10.1186/1297-9716-42-43

Abstract

Parvoviruses of carnivores include three closely related autonomous parvoviruses: canine parvovirus (CPV), feline panleukopenia virus (FPV) and mink enteritis virus (MEV). These viruses cause a variety of serious diseases, especially in young patients, since they have a remarkable predilection for replication in rapidly dividing cells. FPV is not the only parvovirus species which infects cats; in addition to MEV, the new variants of canine parvovirus, CPV-2a, 2b and 2c have also penetrated the feline host-range, and they are able to infect and replicate in cats, causing diseases indistinguishable from feline panleukopenia. Furthermore, as cats are susceptible to both CPV-2 and FPV viruses, superinfection and co-infection with multiple parvovirus strains may occur, potentially facilitating recombination and high genetic heterogeneity. In the light of the importance of cats as a potential source of genetic diversity for parvoviruses and, since feline panleukopenia virus has re-emerged as a major cause of mortality in felines, the present study has explored the molecular characteristics of parvovirus strains circulating in cat populations. The most significant findings reported in this study were (a) the detection of mixed infection FPV/CPV with the presence of one parvovirus variant which is a true intermediate between FPV/CPV and (b) the quasispecies cloud size of one CPV sample variant 2c. In conclusion, this study provides new important results about the evolutionary dynamics of CPV infections in cats, showing that CPV has presumably started a new process of readaptation in feline hosts.

Highlights

Parvoviruses are non-enveloped single-stranded DNA viruses which infect a wide range of mammalian species, including several members of the order Carnivora
feline panleukopenia virus (FPV) infections of cats The present study explored the molecular characteristics of parvovirus strains circulating in cat populations and, limited in the number of sequences analyzed, provides important new findings about the evolutionary dynamics of parvoviruses in cats and the host-virus relationships
Current results have demonstrated that the majority of feline panleukopenia outbreaks are caused by classic FPV strains and that FPV varies at a slow rate by random genetic drift, without a clear temporal or geographical distribution, as has already been reported in a recent study [6]

Summary

Introduction

Parvoviruses are non-enveloped single-stranded DNA viruses which infect a wide range of mammalian species, including several members of the order Carnivora. Parvoviruses of carnivores include three closely related autonomous parvoviruses: canine parvovirus (CPV), feline panleukopenia virus (FPV) and mink enteritis virus (MEV). These viruses cause a variety of serious diseases, especially in young patients, since they have a remarkable predilection for replication in rapidly dividing cells, such as bone marrow, enteric epithelium and the foetus. In consequence of the host range shift of CPV-2 from dog to cats, natural infections of cats and wild felines with CPV-2 have been reported [4], but FPV remains the more prevalent species of parvoviruses causing disease in cats [5]. In some Asian countries, more than 80% of the isolates from cats and wild felines were CPV types, but the precise mechanism of the predominance of CPV-2 in cats in these areas remains obscure [7]

Methods

Results

Conclusion