Isolation and Identification of Three Parvovirus Strains in Raccoon Dogs From Liaoning Province, China

To understand the epidemiological status of parvovirus (RDPV) in raccoon dogs, intestinal tissues of raccoon dogs in Liaoning Province of China were collected and evaluated. Three strains of raccoon dog parvovirus were successfully isolated from 12 intestinal tissues. Nine samples were positive for RDPV, with a positive rate of 75%. The VP2 and NS1 genes of the viruses were cloned and subjected to sequencing for analysis. The nucleotide sequences of the VP2 gene showed 99.94% similarity to the CPV-2a/Racoon dog/QHD/2/19(MT183665) strain, and the nucleotide sequences of the NS1 gene showed 99.75% similarity to RDPV-DP1 NS1(MF996335) strain. The three isolates belonging to the CPV-2a cluster were further confirmed by amino acid sequence alignment and phylogenetic analysis. Our study enriched the epidemiological data of parvovirus in raccoon dogs in the investigating region, and the results will be helpful for future investigation of the variations and transmission of raccoon dog parvoviruses.

ECOLOGICAL ASPECTS OF MORPHOGENESIS OF CONNECTIVE TISSUE COMPONENTS OF THE PANCREAS OF A RACCOON DOG IN POSTNATAL ONTOGENESIS OF THE RADIATION FACTOR

There have been no studies devoted to the study of the pancreas of a raccoon dog living in a contaminated area in the world. Therefore, the aim of our research was to study the connective tissue components of the pancreas in a raccoon dog at different stages of postnatal ontogenesis. The material for the study was raccoon dogs seized from former settlements, in the vicinity of lakes Zhartai, Vyura, Gnezdnoye and the Nesvich River in the exclusion zone (30 – kilometer exclusion zone of the Chernobyl nuclear power plant). As a result of the studies, the features of the morphofunctional state of the pancreatic stroma under the influence of the radiation factor were revealed.

Zoonotic Genotypes of Enterocytozoon bieneusi in Wild Living Invasive and Native Carnivores in Poland

Wild carnivores, both introduced and native species, are able to adapt well to peri-urban environments, facilitating cross-species pathogen transmission with domestic animals, and potentially humans. The role of wild living reservoir hosts cannot be ignored because of their known carriage of E. bieneusi zoonotic genotypes. In the past decades, populations of wild living carnivores, i.e., native, such as red foxes, and invasive, such as raccoon dogs and raccoons, have increased and adapted to synanthropic environments across Europe, including Poland. The knowledge concerning E. bieneusi genotype identification and distribution in wild carnivores is limited worldwide. A total of 322 individual fecal samples from six carnivore species, i.e., raccoon, raccoon dog, red fox, European badger, pine and beech martens, were collected and then analysed for the presence of E. bieneusi using the nested PCR method. Overall prevalence of the pathogen was estimated to be as high as 27.3%. The infection rates for E. bieneusi varied between the carnivore species, from 13.7% in beech martens to 40.4% in raccoon dogs. Based on sequence analysis of the ITS region of the rRNA gene marker, we detected five known genotypes of E. bieneusi in examined animals. In the invasive species, E. bieneusi NCF2 and D genotypes have been identified, whereas in the native ones, E. bieneusi NCF2, D, C, EbCar2 and Type IV genotypes were identified. All E. bieneusi genotypes recorded in this survey clustered in Group 1, showing their zoonotic potential. Our results provide the first description of the occurrence and genotypes of the microsporidian E. bieneusi in wild living population of raccoon dogs in Europe. Our findings are important for the study of pathogen epidemiology and emphasize the fact that the invasive and the native wild living carnivores, both widely distributed, should be considered more seriously as significant sources of zoonotic pathogens hazardous to domestic and farmed animals and humans.

Oral vaccination of foxes and raccoon dogs against rabies with the 3rd generation oral rabies virus vaccine, SPBN GASGAS, in Finland

Background To prevent re-emergence of wildlife-mediated rabies in Finland, oral rabies vaccine baits are distributed every year during autumn in southern Finland in a vaccination zone bordering Russia. Recently, Finland introduced a 3rd generation oral rabies virus vaccine bait. By analysing bait uptake and seroconversion in red foxes and raccoon dogs, the field efficacy of this new vaccine strain, SPBN GASGAS, was compared with the originally used highly efficacious 1st generation vaccine SAD B19. Results Overall, 74.6% and 53.9% of the animals submitted from the vaccination area after the campaigns (2017–2019) tested positive for the presence of the bait marker and anti-rabiesvirus antibodies, respectively. No significant difference was observed between years, species and vaccine. Conclusions The field performance of the highly attenuated 3rd generation oral rabies vaccine, SPBN GASGAS, in terms of bait uptake and seroconversion was similar to the 1st generation vaccine, SAD B19, and therefore offers a suitable alternative.

Behavioral response of wild mammals to pre-existing and artificial latrines of raccoon dogs in northeastern Japan

In this study, we reveal the behavior of raccoon dogs and other mammals on two types of latrines: already-existing latrines in the field and artificial latrines created from the feces of a captive individual. From September to November 2019, we used camera traps at already-known (eight sites), and artificial latrines (four sites), and recorded the mammalian species that visited, their behavior types, and the duration of time spent at the latrines. Our camera traps detected eight species visits, including raccoon dogs, masked palm civets, and rodents (Muridae). In raccoon dogs, sniffing, urination, defecation, and passing were observed, and the numbers of defecation and passing occurrences were significantly higher in the already-existing latrines. The duration time of the raccoon dogs was significantly longer at the artificial latrine; however, the time decreased as days elapsed. Masked palm civets frequently visited the artificial latrines, where the number of rubbings was significantly higher. The Muridae did not differ in their proportion of foraging behavior between the two latrine types, indicating that both were used as feeding sites without distinction. The results of this study indicate that raccoon dog latrines affect not only raccoon dogs but also other mammals.

Viral Metagenomics Reveals Diverse Viruses in the Feces Samples of Raccoon Dogs

Raccoon dogs as an ancient species of Canidae are the host of many viruses, including rabies virus, canine distemper virus, severe acute respiratory syndrome coronavirus, and so on. With the development of raccoon dog breeding in recent years, some viruses which infected poultry or pigs were also detected from raccoon dogs. At present, the fecal virome of raccoon dogs has been rarely studied. Using an unbiased viral metagenomic approach, we investigated the fecal virome in raccoon dogs collected from one farm of Jilin Province, China. Many DNA or RNA viruses identified in those fecal samples were mainly from seven families, including Circoviridae, Smacoviridae, Genomoviridae, Parvoviridae, Picornaviridae, Astroviridae, and Hepeviridae. This study increased our understanding of the fecal virome in raccoon dog and provided valuable information for the monitoring, prevention, and treatment of viral diseases of these animals.

The current state of the golden jackal population in the Lower Dnister National Nature Park

With the advent of the golden jackal in the Lower Dnister, certain changes have taken place in natural complexes, which are primarily related to the impact of the new species on the local fauna. Under such conditions, the number of jackals in certain areas, the spatial structure and location of separate packs are important information for the development of measures aimed at maintaining an optimal abundance of this species. Given the active impact of wildlife on natural systems, there are a number of both biological and purely social problems that need to be addressed. The effectiveness of solving such problems directly depends on the level of study of various aspects of biology and ecology of jackals. In addition, knowledge of the current state of the Dnister jackal population allows timely and effective response to new environmental challenges, which are associated with an increase in the abundance of new species and in its impact on the native mammal fauna. The results of the research indicate a certain competition of the jackal with other species of predatory mammals, in particular the fox and the raccoon dog. Thus, within the territories where the study was carried out, with the appearance of the jackal at the lower course of the Dnister, the red fox was not observed at all and the number of raccoon dogs decreased significantly. Habitats of separate jackal groups within the Lower Dnister National Nature Park have been identified and their total abundance has been established. The dynamics of settlement by the species of the Lower Dnister area is analysed, the conservatism of the species in relation to the residential areas is indicated. It has been established that in some parts of the park, in particular on the northern bank of the Dnister Estuary, the density of animals is about 12 individuals per 1000 hectares, which significantly exceeds the permissible sanitary and epidemiological standards. At the same time, in some parts of the floodplains of the Lower Dnister, density exceeds 0.5 individuals per 1000 ha, which indicates a complex spatial distribution of separate packs and groups of jackals. Mapping of the number of jackals in the park showed that groups far from the estuary are smaller in number (6–14 individuals), whereas groups near the estuary are more abundant (13–20 individuals).

Self-assembled raccoon dog parvovirus VP2 protein confers immunity against RDPV disease in raccoon dogs: in vitro and in vivo studies

Background Raccoon dog parvovirus (RDPV) causes acute infectious diseases in raccoon dogs and may cause death in severe cases. The current treatment strategy relies on the extensive usage of classical inactivated vaccine which is marred by large doses, short immunization cycles and safety concerns. Methods The present study aimed at optimization of RDPV VP2 gene, subcloning the gene into plasmid pET30a, and its subsequent transfer to Escherichia coli with trigger factor 16 for co-expression. The protein thus expressed was purified with ammonium sulfate precipitation, hydrophobic chromatography, and endotoxin extraction procedures. VLPs were examined by transmission electron microscopy, dynamic light scattering, and the efficacy of VLPs vaccine was tested in vivo. Results Results indicated that RDPV VP2 protein could be expressed soluble. Transmission electron microscopy and dynamic light scattering results indicated that RDPV VP2 self-assembled into VLPs. Hemagglutination inhibition antibody titers elicited by Al(OH)3 adjuvanted RDPV VLPs were comparable with RDPV inactivated vaccines, and the viral loads in the blood of the struck raccoon dogs were greatly reduced. Hematoxylin and eosin and Immunohistochemical results indicated that RDPV VLPs vaccine could protect raccoon dogs against RDPV infections. Conclusions These results suggest that RDPV VLPs can become a potential vaccine candidate for RDPV therapy.