Molecular Investigation of Recent Canine Parvovirus-2 (CPV-2) in Italy Revealed Distinct Clustering

Abstract

Canine parvovirus Type 2 (CPV-2) is a worldwide distributed virus considered the major cause of viral gastroenteritis in dogs. Studies on Italian CPV-2 are restricted to viruses circulating until 2017. Only one study provided more updated information on CPV-2 but was limited to the Sicily region. No information regarding the circulation and genetic characteristics of CPV-2 in Northeast Italy has been made available since 2015. The present study investigated the genetic characteristics of CPV-2 circulating in the dog population of Northeast Italy between 2013 and 2019. The VP2 gene of 67 CPV-2 was sequenced, and phylogenetic analysis was performed to identify patterns of distribution. Phylogenetic and molecular analysis highlighted unique characteristics of Northeast Italian CPV-2 and interestingly depicted typical genetic clustering of the Italian CPV-2 strains, showing the existence of distinct CPV-2 genetic groups. Such analysis provided insights into the origin of some Italian CPV-2 genetic clusters, revealing potential introductions from East European countries and the spread of CPV-2 from South/Central to North Italy. This is the first report that describes the genetic characteristics of recent Italian CPV-2. Tracking the genetic characteristics of CPV-2 nationally and globally may have impact on understanding the evolution and distribution of CPV-2, in particular in light of the current humanitarian emergency involving Ukraine, with the massive and uncontrolled movement of people and pet animals.

Identification and Molecular Characterization of a Divergent Asian-like Canine Parvovirus Type 2b (CPV-2b) Strain in Southern Italy

“…Although this strain is phylogenetically close to viruses identified in Australia, phylogenetic analyses did not precisely place it in supported clades including any other known strains; therefore, we unfortunately cannot make a hypothesis about the geographical origin of this strain. Due to the wide distribution of Asian CPV-2c-like strains in Europe [ 14 , 15 , 25 ], the possibility that this Asian-like CPV-2b strain originated from another European or a non-Asian country and was then introduced in Italy cannot be excluded. Nonetheless, the identified mutations could represent a specific molecular marker for perspective future molecular analyses to assess the spread of this virus.…”

Carnivore protoparvovirus 1 (CPV-2 and FPV) Circulating in Wild Carnivores and in Puppies Illegally Imported into North-Eastern Italy

“…Samples were homogenized and nucleic acids were extracted using QIAsymphony DSP Virus/Pathogen Midi kit on the QIAsymphony SP instrument (QIAGEN, Hilden, Germany) or MagMAX Viral/Pathogen II on KingFisher Magnetic Particle Processors (Thermo Fisher Scientific, Waltham, Massachusetts) for dog and wildlife samples, respectively. All samples were screened using molecular testing for canine parvovirus and feline panleukopenia virus [6] using the QuantiFast ® Pathoghen PCR+IC (QIAGEN, Hilden, Germany) as amplification kit and CFX 96 BIO-RAD (BIO-RAD, Hercules, CA, USA) as platform.…”

“…In order to investigate the diversity of parvovirus strains circulating in the area, we performed genetic and phylogenetic analyses for the whole genome and the complete VP2 gene, which is more widely used across the literature. Datasets included positive original samples and the first three non-identical best matches for each sequence, as determined using BLAST reference strains that were previously associated either with dogs in the study area [6] or with wildlife across the world. The selection from the public database included sequences from Italy or wild species tested positive in our study.…”

“…Since its first emergence, CPV-2 was selected in dogs giving rise to several antigenic and genetic variants: CPV-2a, CPV-b, and the most recent subtypes new CPV-2a, new CPV-2b and CPV-2c, that gradually replaced the original type [3,4]. Nowadays, CPV-2 is occasionally detected worldwide likely due to its use as attenuated live vaccine [5,6]. Compared to the original CPV-2, the new variants recovered the ability to infect felids and showed increased pathogenicity [2,7].…”

“…Regardless of the classification used and based on the sequences publicly available, parvoviruses fail to show any significant geographical clustering in dogs, thus suggesting high admixing between populations due to the extensive movement of persons and their pets and, very likely, to the ever-growing commercialization, legal and not, of pups [1]. In this context, it hast been suggested that the black market of puppies might contribute to the spread and evolution of CPV-2 in European count ries with high vaccination coverage, such as Italy [6].…”