Patterns of Genital Tract Mustelid Gammaherpesvirus 1 (Musghv-1) Reactivation Are Linked to Stressors in European Badgers (Meles Meles)

Gammaherpesvirus reactivation can promote diseases or impair reproduction. Understanding reactivation patterns and associated risks of different stressors is therefore important. Nevertheless, outside the laboratory or captive environment, studies on the effects of stress on gammaherpesvirus reactivation in wild mammals are lacking. Here we used Mustelid gammaherpesvirus 1 (MusGHV-1) infection in European badgers (Meles meles) as a host-pathogen wildlife model to study the effects of a variety of demographic, physiological and environmental stressors on virus shedding in the genital tract. We collected 251 genital swabs from 150 free-ranging individuals across three seasons and screened them for the presence of MusGHV-1 DNA using PCR targeting the DNA polymerase gene. We explored possible links between MusGHV-1 DNA presence and seven variables reflecting stressors, using logistic regression analysis. The results reveal different sets of risk factors between juveniles and adults, likely reflecting primary infection and reactivation. In adults, virus shedding was more likely in badgers in poorer body condition and younger than 5 years or older than 7; while in juveniles, virus shedding is more likely in females and individuals in better body condition. However, living in social groups with more cubs was a risk factor for all badgers. We discuss possible explanations for these risk factors and their links to stress in badgers.

Investigation of the viral and bacterial microbiota in intestinal samples from mink (Neovison vison) with pre-weaning diarrhea syndrome using next generation sequencing

Pre-weaning diarrhea (PWD) in mink kits is a common multifactorial syndrome on commercial mink farms. Several potential pathogens such as astroviruses, caliciviruses, Escherichia coli and Staphylococcus delphini have been studied, but the etiology of the syndrome seems complex. In pooled samples from 38 diarrheic and 42 non-diarrheic litters, each comprising of intestinal contents from 2-3 mink kits from the same litter, the bacterial populations were studied using Illumina Next Generation Sequencing technology and targeted 16S amplicon sequencing. In addition, we used deep sequencing to determine and compare the viral intestinal content in 31 healthy non-diarrheic and 30 diarrheic pooled samples (2-3 mink kits from the same litter per pool). The results showed high variations in composition of the bacterial species between the pools. Enterococci, staphylococci and streptococci dominated in both diarrheic and non-diarrheic pools. However, enterococci accounted for 70% of the reads in the diarrheic group compared to 50% in the non-diarrheic group and this increase was at the expense of staphylococci and streptococci which together accounted for 45% and 17% of the reads in the non-diarrheic and diarrheic group, respectively. Moreover, in the diarrheic pools there were more reads assigned to Clostridia, Escherichia-Shigella and Enterobacter compared to the non-diarrheic pools. The taxonomically categorized sequences from the virome showed that the most prevalent viruses in all pools were caliciviruses and mamastroviruses (almost exclusively type 10). However, the numbers of reads assigned to caliciviruses were almost 3 times higher in the diarrheic pools compared the non-diarrheic pools and Sapporo-like caliciviruses were more abundant than the Norwalk-like caliciviruses. The results from this study have contributed to the insight into the changes in the intestinal microbiota associated with the PWD syndrome of mink.

Fecal virome analysis of three carnivores reveals a novel nodavirus and multiple gemycircularviruses

BACKGROUND

More knowledge about viral populations in wild animals is needed in order to better understand and assess the risk of zoonotic diseases. In this study we performed viral metagenomic analysis of fecal samples from three healthy carnivores: a badger (Meles meles), a mongoose (Herpestes ichneumon) and an otter (Lutra lutra) from Portugal.

RESULTS

We detected the presence of novel highly divergent viruses in the fecal material of the carnivores analyzed, such as five gemycircularviruses. Four of these gemycircularviruses were found in the mongoose and one in the badger. In addition we also identified an RNA-dependent RNA polymerase gene from a putative novel member of the Nodaviridae family in the fecal material of the otter.

CONCLUSIONS

Together these results underline that many novel viruses are yet to be discovered and that fecal associated viruses are not always related to disease. Our study expands the knowledge of viral species present in the gut, although the interpretation of the true host species of such novel viruses needs to be reviewed with great caution.

[Sequencing and analysis of N gene of street rabies virus isolated from different hosts in Zhejiang province]

OBJECTIVE

To elucidate the characteristics of genetic variability and its relationship with prevalence, through sequencing and analysis of N gene among street rabies virus isolated from different hosts (homo sapiens, ferret badger, dog) in Zhejiang province.

METHODS

Samples were screened and confirmed by direct fluorescence assay and reverse transcript PCR. Sequences were analyzed using bio-information software.

RESULTS

Eighteen street rabies virus strains were identified, including 2 from homo sapiens, 5 from ferret badger, and 11 from dog. Similarities of N gene and N protein were calculated to be 89.7%-100.0% and 98.4%-100.0% respectively. Mutations occurred in N gene were almost non-sense mutations. In addition,Data from phylogenetic analysis showed that all these strains could be classified into traditional genotype 1.

CONCLUSION

The prevalence of rabies viruses among different hosts in Zhejiang province had certain regional properties. Rabies viruses isolated from the same kind of host or from the same/adjacent county/counties had the closest relationship. However, the characteristics of rabies virus prevalent in homo sapiens were somewhat complicated. In summary, the transmission of street rabies virus in Zhejiang province was from dogs to ferret badgers and homo sapiens, and the virus could circulate and cross-regional transmit among dogs and ferret badgers.

Deduced sequences of the membrane fusion and attachment proteins of canine distemper viruses isolated from dogs and wild animals in Korea

Canine distemper virus (CDV) causes highly contagious respiratory, gastrointestinal, and neurological diseases in wild and domestic animal species. Despite a broad vaccination campaign, the disease is still a serious problem worldwide. In this study, six field CDV strains were isolated from three dogs, two raccoon dogs, and one badger in Korea. The full sequence of the genes encoding fusion (F) and hemagglutinin (H) proteins were compared with those of other CDVs including field and vaccine strains. The phylogenetic analysis for the F and H genes indicated that the two CDV strains isolated from dogs were most closely related to Chinese strains in the Asia-1 genotype. Another four strains were closely related to Japanese strains in the Asia-2 genotype. The six currently isolated strains shared 90.2-92.1% and 88.2-91.8% identities with eight commercial vaccine strains in their nucleotide and amino acid sequences of the F protein, respectively. They also showed 90.1-91.4% and 87.8-90.7% identities with the same vaccine strains in their nucleotide and deduced amino acid sequences of the H protein, respectively. Different N-linked glycosylation sites were identified in the F and H genes of the six isolates from the prototype vaccine strain Onderstepoort. Collectively, these results demonstrate that at least two different CDV genotypes currently exist in Korea. The considerable genetic differences between the vaccine strains and wild-type isolates would be a major factor of the incomplete protection of dogs from CDV infections.

Adaptation of a Chinese ferret badger strain of rabies virus to high-titered growth in BHK-21 cells for canine vaccine development

Rabies virus strain JX08-45CC was derived from a Chinese isolate (JX08-45) by serial passage in the BHK-21 cell line, reaching a titer of 10(8) TCID(50)/mL. JX08-45CC produced rabies in adult mice but was nonpathogenic in dogs after intramuscular injection. A comparison of the entire genomes of JX08-45 and JX08-45CC led to the identification of 17 nucleotide substitutions, resulting in seven amino acid changes in the mature G and L proteins. The immunogenicity of β-propiolactone-inactivated JX08-45CC was similar to the immunogenicity of the live vaccine strains widely used in China. The inactivated vaccine induced antibody responses for more than 6 months and provided full protection from an intramuscular challenge in dogs. JX08-45CC has excellent potential for development as an inactivated vaccine for dogs in China.

[Complete genome sequencing and analyses of rabies viruses isolated from wild animals (Chinese Ferret-Badger) in Zhejiang province]

OBJECTIVE

Based on sequencing the full-length genomes of two Chinese Ferret-Badger, we analyzed the properties of rabies viruses genetic variation in molecular level to get information on prevalence and variation of rabies viruses in Zhejiang, and to enrich the genome database of rabies viruses street strains isolated from Chinese wildlife.

METHODS

Overlapped fragments were amplified by RT-PCR and full-length genomes were assembled to analyze the nucleotide and deduced protein similarities and phylogenetic analyses of the N genes from Chinese Ferret-Badger, sika deer, vole, dog. Vaccine strains were then determined.

RESULTS

The two full-length genomes were completely sequenced to find out that they had the same genetic structure with 11 923 nts including 58 nts-Leader, 1353 nts-NP, 894 nts-PP, 609 nts-MP, 1575 nts-GP, 6386 nts-LP, and 2, 5, 5 nts- intergenic regions (IGRs), 423 nts-Pseudogene-like sequence (Psi), 70 nts-Trailer.

CONCLUSION

The two full-length genomes were in accordance with the properties of Rhabdoviridae Lyssa virus by blast and multi-sequence alignment. The nucleotide and amino acid sequences among Chinese strains had the highest similarity, especially among animals of the same species. Of the two full-length genomes, the similarity in amino acid level was dramatically higher than that in nucleotide level, so that the nucleotide mutations happened in these two genomes were most probably as synonymous mutations. Compared to the referenced rabies viruses, the lengths of the five protein coding regions did not show any changes or recombination, but only with a few-point mutations. It was evident that the five proteins appeared to be stable. The variation sites and types of the two ferret badgers genomes were similar to the referenced vaccine or street strains. The two strains were genotype 1 according to the multi-sequence and phylogenetic analyses, which possessing the distinct geographyphic characteristics of China. All the evidence suggested a cue that these two ferret badgers rabies viruses were likely to be street virus that already circulating in wildlife.

[New animal hosts of rabies virus in mountain areas in Zhejiang province]

OBJECTIVE

To understand the prevalence of rabies among wild animals and the animal species in rabies epidemic areas of Zhejiang province.

METHODS

One hundred and sixty samples were collected from the brain tissues of cats, stoats, Apodemus agrarius, Moschus chinensis, and Sus scrofa in Lishui and Chunan cities of Zhejiang province. Each sample was divided into four parts: cerebrum, mesencephali, cerebellum and gyms hippocampi which were used to determine the positive samples by detection of rabies virus specific antigens and nucleotides, using DFA and RT-PCR methods.

RESULTS

Positive slides in the tests contained a glaring, apple green brilliance fluorescence using rabies virus specific monoclonal antibody against nucleoprotein. Using Nested-PCR method targeted at part of N gene, five positive samples were identified which consisting of four positive samples from stoats with positive ratio as 8.33% (4/48) and one positive sample from Apodemus agrarius with positive ratio as 1.75% (1/57). However, no positive result was found from cats, Moschus chinensis, and Sus scrofa samples.

CONCLUSION

Rabies virus positive samples were identified from stoats and Apodemus agrarius in the mountain areas, with biological diversity in Lishui and Chunan cities of Zhejiang province, indicating that stoats and Apodemus agrarius might have played a role in human rabies and acted as host of rabies virus. In order to effectively prevent and control rabies virus under these complicated geographical and ecological environment, we must understand and evaluate the infection situation among animals in these regions.

Encephalitis in a stone marten (Martes foina) after natural infection with highly pathogenic avian influenza virus subtype H5N1

Recent outbreaks of disease in different avian species, caused by the highly pathogenic avian influenza virus (HPAIV), have involved infection by subtype H5N1 of the virus. This virus has also crossed species barriers and infected felines and humans. Here, we report the natural infection of a stone marten (Martes foina) from an area with numerous confirmed cases of H5N1 HPAIV infection in wild birds. Histopathological examination of tissues from this animal revealed a diffuse nonsuppurative panencephalitis with perivascular cuffing, multifocal gliosis and neuronal necrosis. Additionally, focal necrosis of pancreatic acinar cells was observed. Immunohistochemically, lesions in these organs were associated with avian influenza virus antigen in neurons, glial cells and pancreatic acinar cells. Thus, the microscopical lesions and viral antigen distribution in this stone marten differs from that recently described for cats naturally and experimentally infected with the same virus subtype. This is the first report of natural infection of a mustelid with HPAIV H5N1.

Evidence of canine distemper and suggestion of preceding parvovirus-myocarditis in a Eurasian badger (Meles meles)

An approximately 1.5-yr-old free-ranging male Eurasian badger (Meles meles) from the eastern part of Austria had macroscopic and microscopic lesions consistent with canine distemper virus infection, including nonsuppurative meningoencephalitis, interstitial pneumonia with accumulation of macrophages in alveoli that contained intranuclear inclusion bodies, vesicular exanthema of the ventral abdomen, and atrophy of lymphoid tissues. Canine distemper virus-antigen was demonstrable in a variety of organs by using immunohistology. In addition, there were widespread areas of fibrosis in the myocardium that were rich in collagen and paucicellular. Because such changes are comparable with sequelae of the acute cardiac form of canine parvovirus (CPV) infection in dogs, it was speculated that this badger may have experienced CPV myocarditis as a cub but that the corresponding antigen or DNA was not detectable due to resolution of the disease.

Antigenic characterization of phocine distemper virus causing mass mortality in 2002 and its relationship to other morbilliviruses

The antigenic relationship between the phocine distemper virus (PDV) strain causing the epidemic in 2002 and the PDV strain of 1988, canine distemper virus from two dogs and one marten, and one measles virus strain was investigated in vivo and in vitro using monospecific polyclonal and monoclonal antibodies directed against five different proteins of canine or phocine distemper virus (N, P, M, F, H). Epitopic mapping revealed no difference between the PDV strains causing the epidemics in 1988 or 2002. However, the use of these antibodies allowed discrimination between different morbilliviruses including a vaccine strain of canine distemper virus. The major differences among the investigated morbilliviruses were found in the H protein.

Detection of a novel and highly divergent coronavirus from asian leopard cats and Chinese ferret badgers in Southern China

Since an outbreak of severe acute respiratory syndrome (SARS) was averted in 2004, many novel coronaviruses have been recognized from different species, including humans. Bats have provided the most diverse assemblages of coronaviruses, suggesting that they may be the natural reservoir. Continued virological surveillance has proven to be the best way to avert this infectious disease at the source. Here we provide the first description of a previously unidentified coronavirus lineage detected from wild Asian leopard cats (Prionailurus bengalensis) and Chinese ferret badgers (Melogale moschata) during virological surveillance in southern China. Partial genome analysis revealed a typical coronavirus genome but with a unique putative accessory gene organization. Phylogenetic analyses revealed that the envelope, membrane, and nucleoprotein structural proteins and the two conserved replicase domains, putative RNA-dependent RNA polymerase and RNA helicase, of these novel coronaviruses were most closely related to those of group 3 coronaviruses identified from birds, while the spike protein gene was most closely related to that of group 1 coronaviruses from mammals. However, these viruses always fell into an outgroup phylogenetic relationship with respect to other coronaviruses and had low amino acid similarity to all known coronavirus groups, indicating that they diverged early in the evolutionary history of coronaviruses. These results suggest that these viruses may represent a previously unrecognized evolutionary pathway, or possibly an unidentified coronavirus group. This study demonstrates the importance of systematic virological surveillance in market animals for understanding the evolution and emergence of viruses with infectious potential.

A serologic survey for antibodies to three canine viruses in wolverines (Gulo gulo) from the Brooks Range, Alaska

Canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), and canine adenovirus type 1 (CAV-1) are pathogens that are typically associated with canids but may cause serious disease in a wide range of other carnivores. From 1998 to 2002, serum samples from 64 wolverines (Gulo gulo) from the Brooks Range, Alaska, were tested for antibodies to CDV, CPV-2, and canine adenovirus (CAV). Four animals tested positive for antibodies to CDV (7%), one for antibodies to CPV-2 (2%), and none for antibodies to CAV. These are similar to antibody prevalence estimates for other large and medium carnivores in North America.

Public health concerns in bat rabies across Europe

Rabies due to two independent and different genotypes of lyssaviruses - European bat lyssaviruses (EBLV) type 1 and type 2 - is present in many European countries. Infection is usually seen in bats, the primary reservoirs of the viruses but a few spillover infections have been seen in three other species: stone martens, sheep and humans. Spillover infections (with the exception of the two human cases) were EBLV-1 only. No EBLV-2 spillover cases have been reported in terrestrial animals. The disease is fatal in humans and has been described in Europe following a bat bite. We have studied in the available literature EBLV rabies cases across Europe in bats and humans, and have also carried out an analysis of recommendations for rabies prevention and treatments in humans. Rabies pre-exposure vaccination and post-exposure treatment is recommended for occupationally exposed persons. Some European countries have already adopted recommendations through specific protocols. Treatment of international travellers after bat bites is also recommended. The promoting of research programmes on bat rabies in Europe is underway. Bats are listed as protected species across Europe.

[Rabies epizootic situation in the Novosibirsk region in 1997 - 2003]

Starting from the end of 1997, a rise in the epizooty of rabies with peaks in 1998 and 2002 was noted. 550 cases of rabies were registered in wild and domestic animals, as well as one lethal case of rabies in man in 2001. Wild carnivorous animals are traditionally regarded as the reservoir and source of rabies virus (38%). In the Novosibirsk region this disease was registered in badgers, wild herbivorous animals, myomorph rodents, hares, marmots. Urban cases of rabies constituted 23%, cases of rabies among agricultural animals constituted 14% of all rabies cases in the Novosibirsk region.

[Molecular genetic characterization of rabies virus, isolated in Western Siberia]

The paper covers a study of four rabies viruses, isolated in 2003 from man, wild foxes, badgers and home cats inhabiting entirely different districts of Novosibirsk suburb, and a sample taken from a bat from Maslaninsky district. The samples were studied by fluorescent antibody microscopy and a biological test on white mice, RT-PCR-analysis of NP-genes and sequencing. The study revealed that related variants of rabies viruses circulated in Novosibirsk region, and those formed two groups in genotype 1. Most of the amino acid replacements found in the study are only characteristic of the viruses circulating in the given territory.