Parvoviral host range and cell entry mechanisms

Densovirus infectious pathway requires clathrin-mediated endocytosis followed by trafficking to the nucleus

Junonia coenia densovirus (JcDNV) is an ambisense insect parvovirus highly pathogenic for lepidopteran pests at larval stages. The potential use of DNVs as biological control agents prompted us to reinvestigate the host range and cellular mechanisms of infection. In order to understand the early events of infection, we set up a functional infection assay in a cell line of the pest Lymantria dispar to determine the intracellular pathway undertaken by JcDNV to infect a permissive lepidopteran cell line. Our results show that JcDNV particles are rapidly internalized into clathrin-coated vesicles and slowly traffic within early and late endocytic compartments. Blocking late-endocytic trafficking or neutralizing the pH with drugs inhibited infection. During internalization, disruption of the cytoskeleton, and inhibition of phosphatidylinositol 3-kinase blocked the movement of vesicles containing the virus to the nucleus and impaired infection. In summary, our results define for the first time the early endocytic steps required for a productive DNV infection.

Simple tests for rapid detection of canine parvovirus antigen and canine parvovirus-specific antibodies

Canine parvovirus (CPV) is the number one viral cause of enteritis, morbidity, and mortality in 8-week-old young puppies. We have developed twin assays (slide agglutination test [SAT] for CPV antigen and slide inhibition test [SIT] for CPV antibody) that are sensitive, specific, cost-effective, generic for all genotypes of CPV, and provide instant results for CPV antigen detection in feces and antibody quantification in serum. We found these assays to be useful for routine applications in kennels with large numbers of puppies at risk. The results of these assays are available in 1 min and do not require any special instrumentation. SAT-SIT technology will find applications in rapid screening of samples for other hemagglutinating emerging viruses of animals and humans (influenza virus and severe acute respiratory syndrome coronavirus).

Parvovirus infection in domestic companion animals

Parvovirus infects a wide variety of species. The rapid evolution, environmental resistance, high dose of viral shedding, and interspecies transmission have made some strains of parvovirus infection difficult to control within domestic animal populations. Some parvoviruses in companion animals, such as canine parvovirus (CPV) 1 and feline parvovirus, have demonstrated minimal evolution over time. In contrast, CPV 2 has shown wide adaptability with rapid evolution and frequent mutations. This article briefly discusses these three diseases, with emphasis on virus evolution and the challenges to protecting susceptible companion animal populations.