First Isolation of Cytopathogenic Bovine Torovirus in Cell Culture from a Calf with Diarrhea

Kuwabara, Masaki; Wada, Kazumasa; Maeda, Yukiko; Miyazaki, Akira; Tsunemitsu, Hiroshi

doi:10.1128/cvi.00475-06

Cited by 40 publications

(59 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…That research made available a source of BToV, which facilitated the development of diagnostic tools to study its epidemiology [7]. The cell culture infectivity of some BToV isolates has been recently reported [8,9]. The presence of toroviral particles in human fecal samples and its association with enteric disease has been shown in several reports [10-12], but the molecular information available about the human torovirus (HToV) is still scarce.…”

Section: Introductionmentioning

confidence: 99%

Seroprevalence of porcine torovirus (PToV) in Spanish farms

et al. 2012

View full text Add to dashboard Cite

BackgroundTorovirus infections have been associated with gastroenteritis and diarrhea in horses, cows, pigs and humans, especially in young animals and in children. Although asymptomatic in a large percentage of cases, however toroviruses may pose a potential threat to worsen disease outcome in concurrent infections with other enteric pathogens. Previous studies based on the analysis of limited numbers of samples indicated high seroprevalences against porcine torovirus (PToV) in various European countries. The aim of this work was to perform a seroepidemiological survey of PToV in Spanish farms in order to define the seroprevalence against this virus.ResultsSerum samples (n = 2664) from pigs of different ages were collected from 100 Spanish farms coming from 10 regions that concentrate 96.1% of the 3392 farms with 80 or more sows censused in Spain. Samples were screened by means of an indirect enzyme-linked immune-sorbent assay (ELISA) based on a recombinant PToV nucleocapsid protein as antigen. The analysis of the whole serum collection yielded a total of 95.7% (2550/2664) seropositive samples. The highest prevalence (99.6%, 1382/1388) and ELISA values (average O.D. ± standard deviation) were observed in the sows (1.03±0.36) and the lowest prevalence (59.4%, 98/165) and anti-PToV IgG levels (0.45±0.16) were found amongst 3-week-old piglets. Both ELISA reactivity values and seroprevalence percentages rose quickly with piglet’s age from 3 to 11 weeks of age; the seroprevalence was 99.3% (2254/2270) when only the samples from sows and pigs over 11-weeks of age were considered. Antibodies against PToV were detected in all analyzed farms.ConclusionsThis report describes the results of the largest torovirus seroepidemiological survey in farmed swine performed so far. Overall, the seroprevalence against PToV in animals older than 11 weeks of age was >99%, indicating that this virus is endemic in pig herds from Spain.

show abstract

Section: Introductionmentioning

confidence: 99%

Seroprevalence of porcine torovirus (PToV) in Spanish farms

et al. 2012

View full text Add to dashboard Cite

show abstract

“…This is likely due in part to the fact that torovirus infection has not been associated with disease causing important losses in livestock, but also to the lack of an "in vitro" system to work with most of these viruses, that has precluded the development of specific tools for their diagnosis. For a long time only the equine isolate BEV could be grown in cell cultures (Weiss et al, 1983), and, it has only been very recently reported the ability of a BToV variant isolated in Japan to grow in cells derived from a human rectal adenocarcinoma (Kuwabara et al, 2007). In addition, BToV can be propagated in experimentally infected gnobiotic calves (Woode et al, 1982).…”

Section: Introductionmentioning

confidence: 99%

Molecular characterization of a new PToV strain. Evolutionary implications

et al. 2009

View full text Add to dashboard Cite

Toroviruses are emergent viruses, belonging to the Nidovirales order, that remain mostly ignored, despite they are able to infect different species of domestic animals and humans, causing enteric diseases and diarrhea. Thus far, only five variants of porcine torovirus (PToV) have been identified. In this report we describe the identification and partial characterization of a new strain of porcine torovirus (PToV-BRES) that was detected by RT-PCR in a swine faecal specimen from a farm in Brescia (Italy). The complete genes coding for the nucleocapsid (N), hemagglutinin-esterase (HE) and membrane (M) proteins were amplified, and sequence analysis showed that PToV-BRES is a new PToV strain that, based on the HE gene sequence, is phylogenetically related to P4 strain, that was up to now the only member of a distinct PToV lineage. The nucleocapsid protein from PToV-BRES was expressed in insect cells as a his-tagged protein, purified by affinity chromatography and used to develop an ELISA method to detect antibodies against PToV. This assay was evaluated using a serum collection including 45 samples from three commercial farms from Spain. High antibody prevalence against PToV was observed in the three farms, both in adult animals and in piglets, which could suggest that PToV might be endemic in Spanish porcine population. The ELISA method developed in this work could be useful in future epidemiological surveys about toroviruses.

show abstract

“…Viral isolation via cell culture is the most desirable method for obtaining such epidemiological data, but no reports have described the detection of BToV in cultured cells except for that made by Kuwabara et al (2007) in which cytopathogenic BToV was isolated from HRT-18 cells derived from a human rectal adenocarcinoma. Amplification of the N gene by nested reverse transcription-polymerase chain reaction (RT-PCR) has shown a high degree of conservation among BToV strains (Ito et al, Bovine torovirus (BToV), a member of the Coronaviridae family, is a causative agent of diarrhea in cattle, but it may also possess tropism for the respiratory tract.…”

mentioning

confidence: 99%

“…Additionally, isolation of infectious bovine rhinotracheitis virus (IBRV), bovine viral diarrhea virus (BVDV) and bovine respiratory syncytial virus (BRSV) was performed using bovine testis and bovine kidney cells. Subsequently, the S and HE gene regions of BToV, which have been shown to be correlated with the antigenic properties of coronavirus (Clark, 1993;Gallagher and Buchmeier, 2001;Jackwood et al, 2005;Phillips et al, 2001;Yoo and Deregt, 2001), were amplified from the BToV-N gene-positive samples, and their nucleotide sequences were compared to investigate the level of genetic diversity among the BToVs detected in the nasal samples with one another and against previously collected fecal samples (Draker et al, 2006;Duckmanton et al, 1998b;Ito et al, 2007;Kuwabara et al, 2007;Smits et al, 2003). Nasal swabs were collected from 205 cattle showing respiratory symptoms and 106 asymptomatic cattle raised on 42 farms located in 16 prefectures between March 2006 and June 2008; 264 of the cattle were less than 12 months old.…”

mentioning

confidence: 99%

Detection and characterization of bovine torovirus from the respiratory tract in Japanese cattle

Ito

Okada

Okawa

et al. 2009

Veterinary Microbiology

View full text Add to dashboard Cite

Bovine torovirus (BToV), a member of the Coronaviridae family, is a causative agent of diarrhea in cattle, but it may also possess tropism for the respiratory tract. However, no surveys concerning with the relation between respiratory symptoms and the detection of BToV have been conducted in wide range. Among 311 nasal samples, BToV gene products were detected in seven samples (rBToV-1 to -7) derived only from calves with respiratory symptoms, suggesting that BToV may be a predisposing factor and/or causative agent for bovine respiratory disease. Regarding the degree of similarity between the spike and hemagglutinin-esterase coding regions, the rBToVs showed over 90.8% similarity with one another and 73.5-99.0% similarity with fecal tract-derived BToVs. rBToV-1, -2, and -3 were identical despite their being collected during different seasons; in comparison, rBToV-4 and -5 were distinct despite the fact that they were collected from the same herd, suggesting the existence of diversity among domestic rBToVs. One animal with a BToV-positive nasal sample also shed the virus in its feces, suggesting dual tropisms for BToV.

show abstract

First Isolation of Cytopathogenic Bovine Torovirus in Cell Culture from a Calf with Diarrhea

Cited by 40 publications

References 33 publications

Seroprevalence of porcine torovirus (PToV) in Spanish farms

Seroprevalence of porcine torovirus (PToV) in Spanish farms

Molecular characterization of a new PToV strain. Evolutionary implications

Detection and characterization of bovine torovirus from the respiratory tract in Japanese cattle

Contact Info

Product

Resources

About