Characterization of a canine homolog of human Aichivirus

Evolutionary dynamics of canine kobuvirus in Vietnam and Thailand reveal the evidence of viral ability to evade host immunity

Canine kobuvirus (CaKoV) is a pathogen associated with canine gastrointestinal disease (GID). This study examined 327 rectal swabs (RS), including 113 from Vietnam (46 healthy, 67 with GID) and 214 from Thailand (107 healthy and 107 with GID). CaKoV was detected in both countries, with prevalences of 28.3% (33/113) in Vietnam and 7.9% (17/214) in Thailand. Additionally, CaKoV was found in both dogs with diarrhea and healthy dogs. CaKoV was mainly found in puppies under six months of age (30.8%). Co-detection with other canine viruses were also observed. The complete coding sequence (CDS) of nine Vietnamese and four Thai CaKoV strains were characterized. Phylogenetic analysis revealed a close genetic relationship between Vietnamese and Thai CaKoV strains, which were related to the Chinese strains. CDS analysis indicated a distinct lineage for two Vietnamese CaKoV strains. Selective pressure analysis on the viral capsid (VP1) region showed negative selection, with potential positive selection sites on B-cell epitopes. This study, the first of its kind in Vietnam, provides insights into CaKoV prevalence in dogs of different ages and healthy statuses, updates CaKoV occurrence in Thailand, and sheds light on its molecular characteristics and immune evasion strategies.

Isolation and Characteristics of a Novel Aichivirus D from Yak

Aichivirus D (AiV-D) is a newly emerging Kobuvirus detected in bovine and sheep, and information is limited regarding its biological significance and prevalence. This study aimed to explore both the prevalence and characteristics of AiV-D in yaks. From May to August 2021, 117 fecal samples were collected from yaks with diarrhea in three provinces of China's Qinghai-Tibet Plateau, 15 of which were selected and pooled for metagenomic analysis. A high abundance of AiV-D sequences was obtained. Of the 117 diarrhea samples, 29 (24.8%) tested AiV-D-positive, including 33.3% (14/42) from Sichuan, 21.1% (8/38) from Qinghai, and 18.9% (7/37) from Tibet, respectively, suggesting a wide geographical distribution of the AiV-D in yaks in the Qinghai-Tibet Plateau. Furthermore, three AiV-D strains were successfully isolated using Vero cells. Significantly, the AiV-D strain could cause diarrhea, intestinal bleeding, and inflammation in yak calves via oral inoculation. The virus was distributed in the ileum, jejunum, duodenum, colon, cecum, and rectum. Based on phylogenetic analysis of the genome and capsid protein P1 (VP0, VP3, and VP1 genes), the yak AiV-D strains likely represent a novel genotype of AiV-D. On the whole, this study identified a novel genotype of AiV-D from yaks, which was successfully isolated, and confirmed that this virus is a diarrhea pathogen in yaks and has a wide geographical distribution in the Qinghai-Tibet Plateau. Our results expand the host range of AiV-D and the pathogen spectrum of yaks and have significant implications for diagnosing and controlling diarrhea in yaks. IMPORTANCE In this study, we identified and successfully isolated a novel genotype of AiV-D from yaks. Animal infection confirmed that this virus can cause diarrhea, intestinal bleeding, and inflammation in yak calves via oral inoculation. The virus was distributed in the ileum, jejunum, cecum, duodenum, colon, and rectum. All of these results have significant implications for diagnosing and controlling diarrhea in yaks. These novel AiV-D strains have a wide geographical distribution in yaks from the Qinghai-Tibet Plateau in China. In addition to expanding the host range of AiV-D and the pathogen spectrum of yaks, these findings can increase knowledge of the prevalence and diversity of AiV-D.

Detection and genetic characterization of canine kobuvirus from stray dogs in Shanghai, China

In this study, rectal samples collected from 60 stray dogs in dog shelters were screened for canine kobuvirus and other enteroviruses by quantitative real-time reverse transcription polymerase chain reaction. Canine kobuvirus was detected in 25% (15/60) of the samples. In the 15 positive samples, the coinfection rates of canine distemper virus, canine coronavirus, canine astrovirus, canine norovirus, and canine rotavirus were 26.67%, 20.00%, 73.33%, 0%, and 20.00%, respectively. Phylogenetic analysis based on partial VP1 sequences identified a novel canine kobuvirus that was a recombinant of canine and feline kobuvirus. Bayesian evolutionary analysis revealed that the rate of evolution of the VP1 gene of canine kobuvirus was 1.36 × 10^-4 substitutions per site per year (95% highest posterior density interval, 6.28 × 10^-7 - 4.30 × 10^-4 substitutions per site per year). Finally, the divergence time of VP1 was around 19.44 years ago (95% highest posterior density interval, 12.96-27.57 years).

Detection and Characterization of a Novel Picornavirus in European Badger (Meles meles)

Simple Summary

A molecular survey was performed to investigate the gut virome of wild mustelids and sciurids found dead in Northwestern Italy. Using pan-picornavirus primer pair, we discovered a new picornavirus (PV) in the intestinal content of a European badger (Meles meles). The full-length genome of this novel strain was obtained by a sequence-independent single-primer amplification procedure in combination with Oxford Nanopore Technologies sequencing platform. On sequence analysis, the badger PV could be considered the prototype of a new species, proposed as Sakobuvirus B, classified within the still poorly characterized genus Sakobuvirus. The finding of this study poses interesting questions about the genetic diversity of these viruses, suggesting that the PV host range could be wider than expected.

Abstract

The recent development of unbiased metagenomic next-generation sequencing has provided a richer view of the wild animal virome making it necessary to expand the knowledge about virus diversity in wildlife, as well as to monitor their potential transmission to domestic animals or humans. In the present study, by screening collections of enteric specimens from wild animals, a novel picornavirus was identified in the intestinal content of a badger (Meles meles). By enrichment with a sequence-independent single-primer amplification (SISPA) approach and deep sequencing with Oxford Nanopore Technologies (ONT) platform, the genome sequence of a novel picornavirus strain, Badger/3A-2019/ITA, was reconstructed. On comparison based on the polyprotein sequences, the virus was distantly related (58.7% and 59.7% sequence identity at the nucleotide and amino acid level, respectively) to the feline picornavirus strain FFUP1, identified in 2012 in Portugal and classified into genus Sakobovirus within the species Sakobuvirus A. Upon phylogenetic, pairwise homology, and distance analyses performed on the P1, 2C^hel, 3C^pro, and 3D^pol proteins and the complete genomic sequence, the badger picornavirus may be considered a member of a new sakobuvirus species, which we propose as Sakobuvirus B.

Highly Multiplexed Serology for Nonhuman Mammals

Emerging infectious diseases represent a serious and ongoing threat to humans. Most emerging viruses are maintained in stable relationships with other species of animals, and their emergence within the human population results from cross-species transmission. Therefore, if we want to be prepared for the next emerging virus, we need to broadly characterize the diversity and ecology of viruses currently infecting other animals (i.e., the animal virosphere). High-throughput metagenomic sequencing has accelerated the pace of virus discovery. However, molecular assays can detect only active infections and only if virus is present within the sampled fluid or tissue at the time of collection. In contrast, serological assays measure long-lived antibody responses to infections, which can be detected within the blood, regardless of the infected tissues. Therefore, serological assays can provide a complementary approach for understanding the circulation of viruses, and while serological assays have historically been limited in scope, recent advancements allow thousands to hundreds of thousands of antigens to be assessed simultaneously using <1 μL of blood (i.e., highly multiplexed serology). The application of highly multiplexed serology for the characterization of the animal virosphere is dependent on the availability of reagents that can be used to capture or label antibodies of interest. Here, we evaluate the utility of commercial immunoglobulin-binding proteins (protein A and protein G) to enable highly multiplexed serology in 25 species of nonhuman mammals, and we describe a competitive fluorescence-linked immunosorbent assay (FLISA) that can be used as an initial screen for choosing the most appropriate capture protein for a given host species. IMPORTANCE Antibodies are generated in response to infections with viruses and other pathogens, and they help protect against future exposures. Mature antibodies are long lived, are highly specific, and can bind to their protein targets with high affinity. Thus, antibodies can also provide information about an individual's history of viral exposures, which has important applications for understanding the epidemiology and etiology of disease. In recent years, there have been large advances in the available methods for broadly characterizing antibody-binding profiles, but thus far, these have been utilized primarily with human samples only. Here, we demonstrate that commercial antibody-binding reagents can facilitate modern antibody assays for a wide variety of mammalian species, and we describe an inexpensive and fast approach for choosing the best reagent for each animal species. By studying antibody-binding profiles in captive and wild animals, we can better understand the distribution and prevalence of viruses that could spill over into humans.

Molecular characterization of canine and feline kobuvirus infections in Iran

Kobuviruses are viral pathogens with broad host range presented in human gastroenteritis cases; but, the pathogenesis of these viruses in companion animals is not well described. In the present study, the presence of canine (CaKVs) and feline kobuviruses (FeKVs) was detected in the 100 fecal samples of diarrhoeic and healthy companion dogs and cats by polymerase chain reaction in Tehran, Iran. The prevalence of infection was estimated as 8.00% and 4.00% in dogs and cats, respectively. All positive samples were belonged to non-diarrhoeic animals except for a feline sample being co-infected with panleukopenia. Sequence analysis showed multiple point mutations in canine and feline Iranian strains and new feline strain was detected in the present study. This is the first detection of CaKVs and FeKVs in Iran; but, the exact role of these enteric viral pathogens and their zoonotic risks are better to be clarified in all endemic regions.

Detection of Systemic Canine Kobuvirus Infection in Peripheral Tissues and the Central Nervous System of a Fox Infected with Canine Distemper Virus

Canine kobuvirus (CaKV) is a globally distributed pathogen of dogs and is predominantly associated with infection of the gastrointestinal tract. However, an etiological link to enteric disease has not been established since CaKV has been identified in both asymptomatic dogs and animals with diarrheic symptoms. In this study, an extraintestinal CaKV infection was detected by next-generation sequencing in a fox (Vulpes vulpes) in Germany concomitant with a canine distemper virus (canine morbillivirus; CDV) co-infection. Phylogenetic analysis of the complete coding region sequence showed that this strain was most closely related to a CaKV strain detected in a dog in the United Kingdom in 2008. The tissue and cellular tropism of CaKV was characterized by the detection of viral antigens and RNA. CaKV RNA was detected by in situ hybridization in different tissues, including epithelial cells of the stomach and ependymal cells in the brain. The use of a new RT-qPCR assay for CaKV confirmed the systemic distribution of CaKV with viral RNA also detected in the lymph nodes, bladder, trachea, and brain. The detection of a CDV infection in this fox suggests that immunosuppression should be further investigated as a contributing factor to the enhanced extraintestinal spread of CaKV.

Epidemiology and genetic characteristics of murine kobuvirus from faecal samples of Rattus losea, Rattus tanezumi and Rattus norvegicus in southern China

Recently, murine kobuvirus (MuKV), a novel member of the family Picornaviridae, was identified in faecal samples of Rattus norvegicus in China. The limited information on the circulation of MuKV in other murine rodent species prompted us to investigate its prevalence and conduct a genetic characterization of MuKV in Rattus losea, Rattus tanezumi and Rattus norvegicus in China. Between 2015 and 2017, 243 faecal samples of these three murine rodent species from three regions in southern China were screened for the presence of MuKV. The overall prevalence was 23.0% (56/243). Three complete MuKV polyprotein sequences were acquired, and the genome organization was determined. Phylogenetic analyses suggested that our sequences were closely related to Chinese strains and belong to the species Aichivirus A in the genus Kobuvirus. Additional studies are required to understand the true prevalence of MuKV in murine rodent populations in China.

Molecular Survey on Kobuviruses in Domestic and Wild Ungulates From Northwestern Italian Alps

Since the first identification in 1989 in humans, kobuviruses (KoVs) have been identified from a wide range of animal species including carnivores, rodents, birds, ungulates, rabbits, and bats. Several studies have described the identification of genetically related KoVs in the fecal virome of domestic and wild animals suggesting a mutual exchange of viruses. By screening a total of 231 fecal samples from wild and domestic ungulates, KoVs RNA was detected in wild boars (3.2%; 2/63), chamois (4.6%; 2/43), and goats (2.6%; 2/77). On phylogenetic analysis of the partial RdRp sequence, the wild boar strains clustered within the species Aichivirus C whilst the strains identified in domestic and wild ruminants grouped into the species Aichivirus B. The complete VP1 gene was obtained for chamois and goat KoVs. Interestingly, upon phylogenetic analysis the strains grouped together with a KoV of ovine origin within a distinct genetic type (B3) of the species Aichivirus B.

Genomic characterization and phylogenetic analysis of a new canine picornavirus variant in the mainland of China

A new canine picornavirus (CanPV) variant, designated as dog/SH1901/CHN/2019, was detected in a pool of various canine fecal samples in the mainland of China using a viral metagenomic analysis, and its nearly complete genome sequence was determined and analyzed. Sequence analyses revealed that it had a standard picornavirus genome organization, a type I internal ribosome entry site (IRES) in the 5'UTR. However, dog/SH1901/CHN/2019 has generated a serial of unique aa mutations and 7aa insertion when compared with the closely related CanPVs. Phylogenetic analysis and pairwise sequence comparisons based on the P1, 2C, 3C, and 3D protein sequences showed that dog/SH1901/ CHN/2019 was closely related to CanPV strains 244 F, 325 F and 6D, which clustered into an independent evolutionary clade and distantly related to CanPV strain A128thr of the genus Mischivirus, which indicated the unclassified CanPV strains may belong to a novel species or genus in the family Picornaviridae. This study extends our knowledge on the evolution and genetic diversity of CanPVs.

Duplex SYBR Green I-based real-time PCR assay for the rapid detection of canine kobuvirus and canine astrovirus

A duplex SYBR Green I-based real-time PCR assay was established for the simultaneous detection of canine kobuvirus (CaKoV) and canine astrovirus (CaAstV). This assay can easily distinguish the two viruses according to their different melting temperatures (Tm) of 80 °C for CaKoV and 86.5 °C for CaAstV; other canine enteroviruses used as controls showed no specific melting peaks. The detection limit of this assay was determined to be 10¹ copies/μL for both viruses. This method exhibited high repeatability and reproducibility, with a coefficient of variation less than 1.5 %. A total of 48 fecal samples were collected for clinical testing by real-time PCR and confirmed by sequencing. Real-time PCR assay showed a 10.4 % CaKoV-positive rate and a 4.2 % CaAstV-positive rate, and the positive rate of co-infection of the two viruses was 2.1 %, which was consistent with the sequencing results. This assay has many advantages over conventional PCR: it is rapid, sensitive, specific, and reliable for detecting these two viruses in one sample, and it can be used as a tool to detect CaKoV and CaAstV infection or co-infection in clinical settings.

Development of an SYBR Green I-based real-time PCR assay for the rapid detection of canine kobuvirus

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The first development a SYBR Green I-based real-time PCR assay to detect canine kobuvirus.

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Canine kobuvirus (CaKoV) was detected at a rate of 8.7 % in the Anhui province.

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This method has implications for the prevention and control of CaKoV-infect in dogs.

Canine kobuvirus (CaKoV) is a causative agent of gastroenteritis in dogs. Rapid detection of CaKoV is important for preventing and controlling this condition. In this study, an SYBR Green I-based quantitative real-time PCR assay was established for CaKoV detection. Specific primers targeting a highly conserved region of the CaKoV 3D gene were developed. After optimization, the method detected a minimum of 1 × 10¹ copies/μL with high specificity, stability, and repeatability. Moreover, the entire process only required approximately 1.5 h for completion. Our results were supported by those obtained for clinical samples, in which our developed method was successfully applied. The newly established real-time PCR is a rapid, sensitive, specific, and repeatable method for the quantitative detection of CaKoV and can, therefore, be used in epidemiological studies.

Epidemiological and phylogenetic analysis of canine kobuviruses in Tangshan, China

Canine kobuviruses (CaKoV) have been found in healthy and diarrheic dogs as well as asymptomatic wild carnivores in various countries. In order to investigate the prevalence and evolution of CaKoV in Tangshan, China, 82 dog fecal samples from pet hospitals in Tangshan were subjected to RT-PCR targeting a segment of the 3D gene of CaKoV. Using this method, we identified CaKoV in 14 samples (17.07%, 14/82). Of the CaKoV-positive samples, 78.57% (11/14) and 50% (7/14) were positive for canine parvovirus and canine coronavirus, respectively. The nucleotide sequences of the 14 strains 96.6%–100% identical to each other and 77.6%–99.2% identical to representative sequences from the NCBI GenBank database. We also amplified the 14 VP1 gene sequences and found that they were 93.3%–99.6% identical to each other and 73.3%–97.8% identical to representative sequences from the NCBI GenBank database. Phylogenetic analysis revealed that the 14 CaKoV strains from Tangshan are closely related to those identified in China and Thailand and display less similarity to those found in Africa, the United States, and Europe. Our data suggest that CaKoV circulated in young pet dogs in Tangshan and displays a high co-infection rate with CCoV and CPV. However, the relationship between the three viruses and their roles in the host requires further investigation.

One-step multiplex TaqMan probe-based method for real-time PCR detection of four canine diarrhea viruses

Viral canine diarrhea has high morbidity and mortality and is prevalent worldwide, resulting in severe economic and spiritual losses to pet owners. However, diarrhea pathogens have similar clinical symptoms and are difficult to diagnose clinically. Thus, fast and accurate diagnostic methods are of great significance for prevention and accurate treatment. In this study, we developed a one-step multiplex TaqMan probe-based real-time PCR for the differential diagnosis of four viruses causing canine diarrhea including, CPV (Canine Parvovirus), CCoV (Canine Coronavirus), CAstV (Canine Astrovirus), and CaKoV (Canine Kobuviruses). The limit of detection was up to 10² copies/μL and performed well with high sensitivity and specificity. This assay was optimized and used to identify possible antagonistic relationships between viruses. From this, artificial pre-experiments were performed for mixed infections, and a total of 82 canine diarrhea field samples were collected from different animal hospitals in Zhejiang, China to assess the method. The virus prevalence was significantly higher than what previously reported based on RT-PCR (Reverse Transcription-Polymerase Chain Reaction). Taken together, these results suggest that the method can be used as a preferred tool for monitoring laboratory epidemics, timely prevention, and effective monitoring of disease progression.

A Comprehensive Review on Human Aichi Virus

Although norovirus, rotavirus, adenovirus and Astrovirus are considered the most important viral agents transmitted by food and water, in recent years other viruses, such as Aichi virus (AiV), have emerged as responsible for gastroenteritis outbreaks associated with different foods. AiV belongs to the genus Kobuvirus of the family Picornaviridae. It is a virus with icosahedral morphology that presents a single stranded RNA genome with positive sense (8280 nucleotides) and a poly (A) chain. AiV was first detected from clinical samples and in recent years has been involved in acute gastroenteritis outbreaks from different world regions. Furthermore, several studies conducted in Japan, Germany, France, Tunisia and Spain showed a high prevalence of AiV antibodies in adults (between 80% and 99%), which is indicative of a large exposure to this virus. The aim of this review is to bring together all the discovered information about the emerging pathogen human Aichi virus (AiV), discussing the possibles routes of transmission, new detection techniques and future research. Although AiV is responsible for a low percentage of gastroenteritis outbreaks, the high seroprevalence shown by human populations indicates an evident role as an enteric agent. The low percentage of AiV detection could be explained by the fact that the pathogen is more associated to subclinical infections. Further studies will be needed to clarify the real impact of AiV in human health and its importance as a causative gastroenteritis agent worldwide.

Feline Virome-A Review of Novel Enteric Viruses Detected in Cats

Recent advances in the diagnostic and metagenomic investigations of the feline enteric environment have allowed the identification of several novel viruses that have been associated with gastroenteritis in cats. In the last few years, noroviruses, kobuviruses, and novel parvoviruses have been repetitively detected in diarrheic cats as alone or in mixed infections with other pathogens, raising a number of questions, with particular regards to their pathogenic attitude and clinical impact. In the present article, the current available literature on novel potential feline enteric viruses is reviewed, providing a meaningful update on the etiology, epidemiologic, pathogenetic, clinical, and diagnostic aspects of the infections caused by these pathogens.

Epidemiology of Aichi virus in fecal samples from outpatients with acute gastroenteritis in Northwestern Spain

BACKGROUND

In recent years, Aichi virus (AiV) has been involved in acute viral gastroenteritis outbreaks. However, the common pathogenesis of AiV releases more in subclinical infections underestimating the impact of AiV in human health.

OBJECTIVES

The present study describes the presence and genetic diversity of AiV in patients with gastroenteritis in Northwestern Spain.

STUDY DESIGN

A total of 2667 stool samples, obtained between July 2010 and June 2011, from diarrheic outpatients were studied for detection and molecular characterization of AiV using PCR techniques followed by sequencing and phylogenetic analyses.

RESULTS

The virus was detected in 124 (5.0%) of the samples among all age groups. Coinfections were also detected, from the 124 positive samples, 72 (58.1%) were positive only for AiV, whereas mixed contaminations with Norovirus genogroup I or genogroup II, Sapovirus, or other enteric pathogens were detected in 52 (41.9%) samples. A total of 70 positive samples could be genotyped, being characterized as genotype A (58.6%) or B (41.4%). AiV was detected from August to April, being the highest number of AiV positive samples detected during autumn and winter seasons.

CONCLUSIONS

This survey remarks the importance of emerging enteric viruses in patients who require medical assistance, and offers more information about the real importance of AiV as gastroenteritis agent.

First detection and genetic characterization of canine Kobuvirus in domestic dogs in Thailand

Background

Canine Kobuvirus (CaKoV) has been detected both in healthy and diarrheic dogs and in asymptomatic wild carnivores. In this study, we conducted a survey of CaKoV at small animal hospitals in Bangkok and vicinity of Thailand during September 2016 to September 2018.

Results

Three hundred and seven rectal swab samples were collected from healthy dogs (n = 55) and dogs with gastroenteritis symptoms (n = 252). Of 307 swab samples tested by using one-step RT-PCR specific to 3D gene, we found CaKoV positivity at 17.59% (54/307). CaKoVs could be detected in both sick (19.44%) and healthy (9.09%) animals. In relation to age group, CaKoV could be frequently detected in younger dogs (25.45%). Our result showed no seasonal pattern of CaKoV infection in domestic dogs. In this study, we characterized CaKoVs by whole genome sequencing (n = 4) or 3D and VP1 gene sequencing (n = 8). Genetic and phylogenetic analyses showed that whole genomes of Thai CaKoVs were closely related to Chinese CaKoVs with highest 99.5% amino acid identity suggesting possible origin of CaKoVs in Thailand.

Conclusions

In conclusion, this study was the first to report the detection and genetic characteristics of CaKoVs in domestic dogs in Thailand. CaKoVs could be detected in both sick and healthy dogs. The virus is frequently detected in younger dogs. Thai CaKoVs were genetically closely related and grouped with Chinese CaKoVs. Our result raises the concerns to vet practitioners that diarrhea in dogs due to canine Kobuvirus infection should not be ignored.

Electronic supplementary material

The online version of this article (10.1186/s12917-019-1994-6) contains supplementary material, which is available to authorized users.

Molecular detection of canine bufaviruses in wild canids

Novel protoparvoviruses genetically related to human and non-human primate bufaviruses (BuVs) have been detected recently in respiratory and enteric specimens collected from dogs and cats. In this study, by molecular screening of archival collections of faecal samples from wolves and foxes, we detected BuVs with a rate of 17.1% (7/41) and 10.5% (9/86), respectively. Sequence analysis of a portion of the ORF2 gene region of nine positive samples showed that the viruses in these samples were closely related to BuVs (97.5–99.0% nucleotide sequence identity) found in domestic carnivores.

Detection of canine kobuvirus RNA in diarrheic fecal samples of dogs with parvoviruses

Canine kobuvirus (CaKV) is a member of the Picornaviridae family and the Kobuvirus genus. CaKV was first described in fecal samples from diarrheic dogs in the USA in 2011, with subsequent reports in the UK, Italy, South Korea, China, Tanzania, and Japan. CaKV is frequently identified in feces of animals with or without clinical signs of gastroenteritis. The present study investigated the presence of CaKV in fecal samples from 53 diarrheic dogs from Londrina, southern Brazil. Using a RT-PCR assay, CaKV RNA was identified in three dogs, resulting in an overall occurrence rate of 5.7%. In addition, coinfection with canine parvovirus subtype 2b was detected in all CaKV-positive diarrheic fecal samples. Using a phylogenetic analysis based on the VP1 gene sequence, the Brazilian CaKV field strains were found to be very similar to a previously identified CaKV strain from Brazil that was found in the tissue of a puppy and were also found to be clustered with other CaKV strains detected worldwide and other kobuvirus strains identified in mouse, feline, and human hosts.

New Parvovirus Associated with Serum Hepatitis in Horses after Inoculation of Common Biological Product

Equine serum hepatitis (i.e., Theiler's disease) is a serious and often life-threatening disease of unknown etiology that affects horses. A horse in Nebraska, USA, with serum hepatitis died 65 days after treatment with equine-origin tetanus antitoxin. We identified an unknown parvovirus in serum and liver of the dead horse and in the administered antitoxin. The equine parvovirus-hepatitis (EqPV-H) shares <50% protein identity with its phylogenetic relatives of the genus Copiparvovirus. Next, we experimentally infected 2 horses using a tetanus antitoxin contaminated with EqPV-H. Viremia developed, the horses seroconverted, and acute hepatitis developed that was confirmed by clinical, biochemical, and histopathologic testing. We also determined that EqPV-H is an endemic infection because, in a cohort of 100 clinically normal adult horses, 13 were viremic and 15 were seropositive. We identified a new virus associated with equine serum hepatitis and confirmed its pathogenicity and transmissibility through contaminated biological products.

Detection and genetic characterization of kobuvirus in cats: The first molecular evidence from Northeast China

Feline kobuvirus (FeKoV), a novel picornavirus of the genus kobuvirus, was initially identified in the feces of cats with diarrhea in South Korea in 2013. To date, there is only one report of the circulation of kobuvirus in cats in southern China. To investigate the presence and genetic variability of FeKoV in northeast China, 197 fecal samples were collected from 105 cats with obvious diarrhea and 92 asymptomatic cats in Shenyang, Jinzhou, Changchun, Jilin and Harbin regions, Northeast China, and viruses were detected by RT-PCR with universal primers targeting all kobuviruses. Kobuvirus was identified in 28 fecal samples with an overall prevalence of 14.2% (28/197) of which 20 samples were co-infected with feline parvovirus (FPV) and/or feline bocavirus (FBoV). Diarrhoeic cats had a higher kobuvirus prevalence (19.1%, 20/105) than asymptomatic cats (8.7%, 8/92). By genetic analysis based on partial 3D gene, all kobuvirus-positive samples were more closely related to previous FeKoV strains with high identities of 90.5%-97.8% and 96.6%-100% at the nucleotide and amino acid levels. Additionally, phylogenetic analysis based on the complete VP1 gene indicated that all FeKoV strains identified in this study were placed into a cluster, which separated from other reference strains previously reported, and three identical amino acid substitutions were present at the C-terminal of the VP1 protein for these FeKoV strains. Furthermore, two complete FeKoV polyprotein genomes were successfully obtained from two positive samples and designated 16JZ0605 and 17CC0811, respectively. The two strains shared 92.9%-94.9% nucleotide identities and 96.8%-98.4% amino acid identities to FeKoV prototype strains. Phylogenetic analysis indicated that FeKoVs were clustered according to their geographical regions, albeit with limited sequences support. This study provides the first molecular evidence that FeKoV circulates in cats in northeast China, and these FeKoVs exhibit genetic diversity and unique evolutionary trend.

First report and genetic characterization of feline kobuvirus in diarrhoeic cats in China

Feline kobuvirus (FeKoV) is a newly discovered organism, classified under the species Aichivirus A of the genus Kobuvirus. Since it was first reported in 2013, molecular evidence for FeKoV in the feline population has been restricted to two countries: Korea and Italy. In this study, we collected faecal samples from cats in southern China and detected the FeKoV RNA in these samples. A prevalence rate of 9.9% (8/81) was identified by RT‐PCR, and all positive samples were obtained from diarrhoeic animals. In addition, FeKoV was shown positive associated with diarrhoea in cats, with a correlation coefficient of 0.25. Next, we designed three primer pairs with degenerate bases, which targeted the conservative overlapping region of the entire published FeKoV genome, and sequenced the near‐complete genome of the first Chinese field FeKoV strain, WHJ‐1, using long‐fragment PCR. Finally, we analysed WHJ‐1's homology and phylogeny using the polyprotein gene. The results indicated that FeKoV has rapidly mutated since it was first discovered. This study will help to better understand FeKoV's epidemiology, evolutionary pattern and genetic diversity.

Occurrence of Aichi virus in retail shellfish in Italy

AiV-1 is considered an emerging human enteric pathogens and foodborne transmission has been documented as an important source of exposure for humans, chiefly in relation to non-safe, risky food habits. We surveyed the presence of AiV-1 in retail shellfish, including oysters and mussles, identifying the virus in 3/170 (1.8%) of the analysed samples. The AiV-1 positive samples were of different geographic origin. Upon sequence analysis of a portion of the 3CD junction region, two AiV strains identified from harvesting areas in Northern Italy were characterised as genotype B and displayed 99-100% identity at the nucleotide level to other AiV-1 strains detected in sewages in Central Italy in 2012, suggesting that such strains are stably circulating in Italian ecosystems. Interestingly, a strain identified from mussles harvested in Southern Italy could not be characterised firmly, as inferred in the Bayesian analysis and by sequence comparison, indicating that different AiV strains are also circulating in Italy. Viral contamination in retail shellfish challenges the microbiological guidelines for food control and requires the development and optimization of additional diagnostic and prevention strategies.

New viruses associated with canine gastroenteritis

A number of novel viruses have been associated with canine gastroenteritis in recent years, from viral families as diverse as Caliciviridae and Picornaviridae to Parvoviridae and Circoviridae. The ability of many of these viruses to cause disease is uncertain, but epidemiological studies are continually adding to our knowledge of these potential pathogens. This review presents a summary of the latest research and current understanding of novel viruses associated with canine gastroenteritis.

One-step triplex PCR/RT-PCR to detect canine distemper virus, canine parvovirus and canine kobuvirus

To rapidly distinguish Canine distemper virus (CDV), canine parvovirus (CPV), and canine kobuvirus (CaKoV) in practice, a one-step multiplex PCR/RT-PCR assay was developed, with detection limits of 10^2.1 TCID₅₀ for CDV, 10^1.9 TCID₅₀ for CPV and 10³ copies for CaKoV. This method did not amplify nonspecific DNA or RNA from other canine viruses. Therefore, the assay provides a sensitive tool for the rapid clinical detection and epidemiological surveillance of CDV, CPV and CaKoV in dogs.

Genetic diversity and cross-species transmission of kobuviruses in Vietnam

Cross-species transmission of viruses poses a sustained threat to public health. Due to increased contact between humans and other animal species the possibility exists for cross-species transmissions and ensuing disease outbreaks. By using conventional PCR amplification and next generation sequencing, we obtained 130 partial or full genome kobuvirus sequences from humans in a sentinel cohort in Vietnam and various mammalian hosts including bats, rodents, pigs, cats, and civets. The evolution of kobuviruses in different hosts was analysed using Bayesian phylogenetic methods. We estimated and compared time of origin of kobuviruses in different host orders; we also examined the cross-species transmission of kobuviruses within the same host order and between different host orders. Our data provide new knowledge of rodent and bat kobuviruses, which are most closely related to human kobuviruses. The novel bat kobuviruses isolated from bat roosts in Southern Vietnam were genetically distinct from previously described bat kobuviruses, but closely related to kobuviruses found in rodents. We additionally found evidence of frequent cross-species transmissions of kobuviruses within rodents. Overall, our phylogenetic analyses reveal multiple cross-species transmissions both within and among mammalian species, which increases our understanding of kobuviruses genetic diversity and the complexity of their evolutionary history.

The Strange, Expanding World of Animal Hepaciviruses

Hepaciviruses and pegiviruses constitute two closely related sister genera of the family Flaviviridae. In the past five years, the known phylogenetic diversity of the hepacivirus genera has absolutely exploded. What was once an isolated infection in humans (and possibly other primates) has now expanded to include horses, rodents, bats, colobus monkeys, cows, and, most recently, catsharks, shedding new light on the genetic diversity and host range of hepaciviruses. Interestingly, despite the identification of these many animal and primate hepaciviruses, the equine hepaciviruses remain the closest genetic relatives of the human hepaciviruses, providing an intriguing clue to the zoonotic source of hepatitis C virus. This review summarizes the significance of these studies and discusses current thinking about the origin and evolution of the animal hepaciviruses as well as their potential usage as surrogate models for the study of hepatitis C virus.

First molecular identification of kobuviruses in wolves (Canis lupus) in Italy

Canine kobuviruses (CaKoVs) were first identified in diarrhoeic and asymptomatic dogs in 2011 in the USA. Subsequent studies have demonstrated a worldwide distribution of these viruses, but it is not clear if CaKoVs play a role as enteric pathogens of dogs. More recently, CaKoV RNA has been detected in wild carnivores, including red fox, golden jackal, side-striped jackal and spotted hyena. In this study, we addressed the hypothesis that wolves are susceptible to CaKoV infections. A total of 185 wolf stool samples were collected from necropsied animals and from transects in the Liguria, Piemonte and Valle D'Aosta regions of Italy, and CaKoV RNA was identified in two of these specimens. Both samples were obtained from necropsied wolves, with a prevalence rate of 4.9% (2/41). Sequence analysis of the full-length VP1 region showed that these strains displayed the highest nucleotide (nt) sequence identity (86.3-98.5%) to canine strains identified in the UK and Africa, and to kobuviruses that were previously detected in other African wild carnivores. This suggests that genetically related CaKoV strains circulate in domestic and wild carnivores, with interspecies transmission being not uncommon among carnivores of different ecosystems.

Identification by next-generation sequencing of Aichivirus B in a calf with enterocolitis and neurologic signs

An 11-d-old Holstein bull calf was presented to the Veterinary Medical Teaching Hospital at the University of Wisconsin-Madison because of a 4-d history of diarrhea and persistent low-grade fever. Initial diagnosis was enteritis caused by Cryptosporidium and rotavirus. During hospitalization, the calf became stuporous and was only responsive to noxious stimuli, with hypotonia of all 4 limbs, tail, head, and neck. A cerebrospinal fluid analysis revealed xanthochromia, with marked lymphocytic pleocytosis, which was suggestive of viral meningitis and/or encephalitis. Aichivirus B, which belongs to the Kobuvirus genus, was tentatively identified in spinal fluid by next-generation DNA sequencing. This virus can affect a multitude of species, including humans and cattle, and has been isolated from both healthy and diarrheic individuals. However, to date, a possible connection with neurologic disease has not been described, to our knowledge.

Taxonomic Changes and Additions for Human and Animal Viruses, 2012 to 2015

Taxonomical classification of newly discovered viruses and reclassification of previously discovered viruses provide an important foundation for detailing biological differences of scientific and clinical interest. The development of molecular analytical methods has enabled finer levels and more precise levels of classification. Periodically, there is need to refresh the literature and common understanding of current taxonomic classification, which we attempt to do here in addressing changes in human and animal viruses of medical significance between 2012 and 2015.

Molecular characterization of new described kobuvirus in dogs with diarrhea in China

Canine kobuvirus (CaKVs) was a newly described virus detected in dogs in the US and Italy. To learn more about CaKVs, 5 of 106 fecal samples from diarrhea dogs were positive with CaKVs in China, and the full genome of CaKVs strain CH-1 isolated from dog with diarrhea was sequenced. The genome consists of 8186 nucleotides, excluding the 3′ poly (A) tail, and an open reading frame that maps between nucleotide positions 601 and 7943 which encodes a 2446 amino acid polyprotein. Based on the complete amino acid sequence of polyprotein, phylogenetic analysis showed that CH-1 was grouped along with other canine kobuvirus strains detected in the USA (US-PC0082, AN211D).

Extra-intestinal detection of canine kobuvirus in a puppy from Southern Brazil

This study presents the pathological, immunohistochemical, and molecular findings associated with the extra-intestinal detection of canine kobuvirus (CaKV) in a 5-month-old Chihuahua puppy, that had a clinical history of bloody-tinged feces. Principal pathological findings were interstitial pneumonia, necrotizing bronchitis, and parvovirus-induced enteritis. Molecular diagnostic methods identified CaKV within the cerebellum, cerebrum, lung, tonsil, and liver. CaKV and rotavirus were not identified within the feces and intestine. Immunohistochemistry (IHC) assays detected antigens of CDV and CAdV-1 in the lungs. These results confirmed the extra-intestinal detection of CaKV in this puppy and represent the first extra-intestinal detection of CaKV in a dog.

Detection of kobuvirus RNA in Japanese domestic dogs

To investigate whether kokuvirus is present in Japanese dogs, we examined the fecal samples obtained from 94 diarrheal household dogs and 50 clinically healthy kenneled dogs by RT-PCR. The gene was detected in 37.2% and 48.0% in the former and the latter, respectively, suggesting that canine kobuvirus (CaKoV) is circulating among Japanese dogs. From the result of the latter, however, CaKoV may not be a primary pathogen. Furthermore, all gene-positive dogs were purebreds aged four months or younger. This finding suggests that CaKoV endemic is confined in multi-dog environments, and the dogs have a strong age-dependent resistance to CaKoV.

Detection and characterization of Aichi virus 1 in pediatric patients with diarrhea in Thailand

Kobuvirus is a newly discovered virus that belongs to the Kobuvirus genus in Picornaviridae family, which comprised of three species including Aichivirus A, Aichivirus B, and Aichivirus C. The kobuvirus isolated from human has been classified as Aichi virus 1 and belongs to Aichivirus A species. The present study aimed to assess the epidemiology and to perform molecular characterization of Aichi virus 1 in children admitted to hospitals with acute gastroenteritis in Chiang Mai, Thailand. A total of 923 fecal specimens collected from January, 2011 to December, 2013 were screened for the presence of Aichi virus 1 by RT semi-nested PCR. Out of 923 fecal specimens tested, Aichi virus 1 was detected with the prevalence of 2.6% (24/923). Of these, 0.3% (3/923) was genotype A and 2.3% (21/923) were genotype B. It is interesting to note that the genotype A showed the nucleotide sequence closely related to the Aichi virus reference strain isolated from sewage in Tunisia, while genotype B was most closely related to other human Aichi virus B reference strains. The results suggest that Aichi virus 1 of both genotypes A and B are circulating in pediatric patients in Thailand. J. Med. Virol. 89:234-238, 2017. © 2016 Wiley Periodicals, Inc.

Molecular epidemiology of canine picornavirus in Hong Kong and Dubai and proposal of a novel genus in Picornaviridae

Previously, we reported the discovery of a novel canine picornavirus (CanPV) in the fecal sample of a dog. In this molecular epidemiology study, CanPV was detected in 15 (1.11%) of 1347 canine fecal samples from Hong Kong and one (0.76%) of 131 canine fecal samples from Dubai, with viral loads 1.06×10(3) to 6.64×10(6) copies/ml. Complete genome sequencing and phylogenetic analysis showed that CanPV was clustered with feline picornavirus (FePV), bat picornavirus (BatPV) 1 to 3, Ia io picornavirus 1 (IaioPV1) and bovine picornavirus (BoPV), and this cluster was most closely related to the genera Enterovirus and Sapelovirus. The Ka/Ks ratios of all the coding regions were <0.1. According to the definition of the Picornavirus Study Group of ICTV, CanPV, FePV, BatPV 1 to 3, IaioPV1 and BoPV should constitute a novel genus in Picornaviridae. BEAST analysis showed that this genus diverged from its most closely related genus, Sapelovirus, about 49 years ago.

Development of TaqMan real-time reverse transcription-polymerase chain reaction for the detection and quantitation of porcine kobuvirus

Porcine kobuvirus (PKV) is a newly emerging virus that has been detected in diarrheic pigs. Presently, reverse transcription-polymerase chain reaction (RT-PCR) and RT-loop-mediated amplification are the only methods that can be used to detect PKV. To develop a TaqMan real-time RT-PCR for the rapid detection and quantitation of PKV nucleic acid in fecal samples, a pair of primers and a probe were designed to amplify the conserved 3D region of the PKV genome. After optimization, the TaqMan real-time RT-PCR was highly specific and ∼1000 times more sensitive than conventional RT-PCR, and the detection limit was as low as 30 DNA copies. Among the 148 intestinal samples from piglets with diarrhea, 136 and 118 were positive based on the TaqMan and conventional RT-PCR methods, respectively, indicating that the TaqMan RT-PCR was more sensitive than conventional RT-PCR, and the total concordance of the two methods was approximately 87.84%. Thus, the TaqMan real-time RT-PCR should be a useful tool for the early detection and quantitation of PKV.

Prevalence and phylogenetic analysis of canine kobuviruses in diarrhoetic dogs in northeast China

Canine kobuviruses (CaKVs) are newly recognized picornaviruses that have been recently detected in dogs in the U.S.A., Italy, U.K., the Republic of Korea and Tanzania. To trace the evolution of CaKV strains, a total of 201 fecal samples from rectal swabs of diarrheic dogs, which were obtained from May 2014 to April 2015 in northeast China, were detected by reverse transcription-PCR targeting a partial (504 bp) fragment of the 3D gene. Furthermore, a phylogenetic analysis of the CaKV strains identified in northeast China was conducted based on the partial 3D gene sequence. The results indicated that 36 fecal samples (17.91%, 36/201) were positive for CaKV, in which the co-infection rates of canine coronavirus, canine parvovirus-2 and canine bocavirus were 58.33%, 41.67%, and 11.11%, respectively. Sequence comparison of the partial 3D gene revealed nucleotide homologies of 94.4-100%, 95.6-98.6%, 94.3-97.6%, 94.4-96.3% and 93.3-95.1% within the 36 Chinese CaKV strains, and between the 36 Chinese CaKV strains and four CaKV reference strains from South Korea, Italy, U.S.A. and Tanzania, respectively. A phylogenetic tree revealed that the 36 Chinese CaKV strains formed one specific CaKV lineage with CaKVs that have recently been identified in other countries. The 36 Chinese CaKV strains were closely related to CaKV reference strains from Asia and Europe, but differed genetically from CaKV reference strains from North America and Africa. This study provides evidence that CaKVs circulate in diarrhoetic dogs in China and that they exhibit substantial genetic diversity and high co-infection rates with other enteric viruses.

Aichi virus 1: environmental occurrence and behavior

Aichi virus 1 (AiV-1), belonging to the genus Kobuvirus in the family Picornaviridae, has been proposed as a causative agent of human gastroenteritis potentially transmitted by fecal-oral routes through contaminated food or water. AiV-1 is globally distributed and has been detected in various types of environmental samples, such as sewage, river water, groundwater, and shellfish. Recent environmental studies revealed that this virus could be detected in higher frequency and greater abundance than other human enteric viruses. These findings suggest that AiV-1 could potentially be an appropriate indicator of viral contamination in the environment because of its high prevalence in water environments as well as structural and genetic similarity with some of the other important enteric viruses. Further studies on the occurrence and fate of AiV-1 in environments, even in combination with clinical studies of many regions, are needed for a better understanding of their epidemiology, temporal and geographical distribution, environmental stability, and potential health risks to humans.

Molecular characterization of canine kobuvirus in wild carnivores and the domestic dog in Africa

Knowledge of Kobuvirus (Family Picornaviridae) infection in carnivores is limited and has not been described in domestic or wild carnivores in Africa. To fill this gap in knowledge we used RT-PCR to screen fresh feces from several African carnivores. We detected kobuvirus RNA in samples from domestic dog, golden jackal, side-striped jackal and spotted hyena. Using next generation sequencing we obtained one complete Kobuvirus genome sequence from each of these species. Our phylogenetic analyses revealed canine kobuvirus (CaKV) infection in all four species and placed CaKVs from Africa together and separately from CaKVs from elsewhere. Wild carnivore strains were more closely related to each other than to those from domestic dogs. We found that the secondary structure model of the IRES was similar to the Aichivirus-like IRES subclass and was conserved among African strains. We describe the first CaKVs from Africa and extend the known host range of CaKV.

Detection of feline kobuviruses in diarrhoeic cats, Italy

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Kobuviruses were found in cats with diarrhoea.

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Kobuviruses were not detected in asymptomatic cats.

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The complete genome sequence of one such strains was determined.

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Kobuviruses resembling the newly described feline kobuviruses were identified.

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First evidence on the circulation of feline kobuviruses outside the Asian continent.

Kobuviruses have been identified in the enteric tract of several mammalian species but their role as enteric pathogens is still not defined. In this study, feline kobuviruses were found in 13.5% of cats with diarrhoea, but not in asymptomatic animals. In the full-length genome, one such strains, TE/52/13/ITA, displayed the highest nucleotide identity (96.0%) to the prototype strain FK-13. These results provide firm evidence that kobuviruses are common constituents of feline enteric viroma and that they are not geographically restricted to the Asian continent, where they were first signalled.

Genetic characteristics of the complete feline kobuvirus genome

We sequenced the complete genome of a feline kobuvirus and determined relationships with other kobuviruses. This kobuvirus has an 8,269-nucleotide-long RNA genome, excluding the poly(A) tail. The genome contains a 7,311-bp open reading frame (ORF) encoding a putative polyprotein precursor of 2,437 amino acids, a 717-bp 5'-untranslated region (UTR), and a 241-bp 3'-UTR. The L protein sequence was found to be the most variable region in the feline kobuvirus genome. Interestingly, the 5'-UTR B and C stem-loops were conserved as observed with other kobuviruses; however, a secondary structure corresponding to stem-loop A was not found in the full length 5'-UTR sequence. Phylogenetic tree analysis showed that kobuviruses can be divided into 3 main groups. The feline kobuvirus belongs to the Aichivirus A species containing Aichivirus, mouse kobuvirus, and canine kobuvirus.

Canine kobuvirus infections in Korean dogs

To investigate canine kobuvirus (CaKoV) infection, fecal samples (n = 59) were collected from dogs with or without diarrhea (n = 21 and 38, respectively) in the Republic of Korea (ROK) in 2012. CaKoV infection was detected in four diarrheic samples (19.0 %) and five non-diarrheic samples (13.2 %). All CaKoV-positive dogs with diarrhea were found to be infected in mixed infections with canine distemper virus and canine parvovirus or canine adenovirus. There was no significant difference in the prevalence of CaKoV in dogs with and without diarrhea. By phylogenetic analysis based on partial 3D genes and complete genome sequences, the Korean isolates were found to be closely related to each other regardless of whether they were associated with diarrhea, and to the canine kobuviruses identified in the USA and UK. This study supports the conclusion that CaKoVs from different countries are not restricted geographically and belong to a single lineage.

Viral metagenomic analysis of feces of wild small carnivores

Background

Recent studies have clearly demonstrated the enormous virus diversity that exists among wild animals. This exemplifies the required expansion of our knowledge of the virus diversity present in wildlife, as well as the potential transmission of these viruses to domestic animals or humans.

Methods

In the present study we evaluated the viral diversity of fecal samples (n = 42) collected from 10 different species of wild small carnivores inhabiting the northern part of Spain using random PCR in combination with next-generation sequencing. Samples were collected from American mink (Neovison vison), European mink (Mustela lutreola), European polecat (Mustela putorius), European pine marten (Martes martes), stone marten (Martes foina), Eurasian otter (Lutra lutra) and Eurasian badger (Meles meles) of the family of Mustelidae; common genet (Genetta genetta) of the family of Viverridae; red fox (Vulpes vulpes) of the family of Canidae and European wild cat (Felis silvestris) of the family of Felidae.

Results

A number of sequences of possible novel viruses or virus variants were detected, including a theilovirus, phleboviruses, an amdovirus, a kobuvirus and picobirnaviruses.

Conclusions

Using random PCR in combination with next generation sequencing, sequences of various novel viruses or virus variants were detected in fecal samples collected from Spanish carnivores. Detected novel viruses highlight the viral diversity that is present in fecal material of wild carnivores.