Orbivirus screening on dried blood spots from captive oryx in United Arab Emirates stresses the importance of pre-import measures
Martinelle, Ludovic ; ; et al
Poster (2015, September 01)
Objective: Following reintroduction and conservation programs of the Arabian oryx (Oryx leucoryx) and the scimitar horned oryx (SHO, Oryx dammah) in the United Arab Emirates (UAE), import of animals from ... [more ▼]
Objective: Following reintroduction and conservation programs of the Arabian oryx (Oryx leucoryx) and the scimitar horned oryx (SHO, Oryx dammah) in the United Arab Emirates (UAE), import of animals from wild game ranches in the United States of America (USA) is not uncommon. Bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) are orbiviruses that are the causative agents of bluetongue disease (BT) and epizootic hemorrhagic disease (EHD), respectively. BTV and EHDV are endemic in the UAE and the USA. Sheep and some wild ruminant species are usually severely affected by BT whereas EHD mostly affects wild animals and sometimes cattle. The objective of this study was to estimate the prevalence of these orbiviruses in Arabian and SHO from captive herds in the UAE using serology and molecular virology. Dry blood spot sampling for orbivirus screening is also discussed. Methods: A total of 175 SHO and 16 Arabian oryx were sampled. The latters were imported from Texas (USA) two weeks before sampling. All sampled animals belonged to captive herds spread over the Al Wathba area. For biosecurity reasons and to simplify blood storage, elutes from dried blood spot were used for serological and virological tests. Drops of about 80 µl of blood were dispensed on Whatman protein saver cards, and then allowed to dry in the dark at room temperature for 48 hours. Blood spots were punched out in paper discs with a 6 mm diameter punch and diluted in 250 µl PBS and Tween 20 0.05%. Eluted samples were incubated overnight at room temperature and then used immediately or stored at -80°C. To assess the most suitable ELISA kit to detect anti-BTV antibodies from the oryx discs, similar discs were prepared using blood issued from BTV seropositive and viremic as well as seronegative and non-viremic cattle. Elutes from discs with dried-blood from cattle were tested by BTV competitive ELISA (cELISA), sandwich ELISA (sELISA) and indirect ELISA (iELISA) and compared to cELISA performed directly on the serum of the same animals. iELISA on cattle paper discs gave the best correspondence with cELISA on cattle serum and was therefore used to test the oryx paper discs. Subsequently oryx paper discs were tested to detect antibodies against EHDV by cELISA. All the paper discs elutes from Arabian oryx and ELISA positive elutes from SHO were also tested by pan-BTV RTqPCR targeting a fragment of BTV segment 5 and detecting all BTV serotypes. Serotype specific end-point RT-PCR targeting a fragment of segment 2 of BTV2, BTV8, BTV10, BTV11, BTV13 and BTV17 were performed on pan-BTV positive samples. Results: Three out of 175 SHO and eight out of 16 Arabian oryx were found BTV seropositive by iELISA. None of the animals could be found seropositive against EHDV. BTV genome was detected in 1/3 seropositive SHO and in 5/16 of the Arabian oryx, amongst those 2/5 were seronegative. Overall Cq values were high (33-39). End point PCR failed to detect positive samples for any of the tested serotypes. Conclusion: BTV seroprevalence and RNA detection in SHO was very limited. By contrast BTV could be demonstrated in 5/16 imported Arabian oryx by molecular virology and in 8/16 by serology. The sampling was realized two weeks after the animals arrived in UAE and some oryx were viremic and seronegative, possibly suggesting a recent infection. Among the local SHO a low BTV seroprevalence was observed (3/175) and no animals were found positive to EHDV. This result was quite surprising because previous studies showed a higher BTV seroprevalence in domestic and wild ruminants of the Arabian Peninsula with wide local variations. In addition, dried blood spot testing has been demonstrated being a convenient and reliable method of sampling when storage conditions are hazardous. BTV serotypes could not be determined by end-point RT-PCR. At least 15 different BTV serotypes were reported in the USA and at least 10 in the Middle East, thus the oryx could be infected by a serotype not tested so far. Since RTqPCR positive values were high, the sensitivity of end-point RT-PCR might be insufficient to detect BTV out of eluted blood spots. Additional testing will be performed to identify the virus on the serotype level and therefore provide new insights to clarify the origin of the infection of the oryx. These results stress the need for pre-import risk assessment, precaution and implementation of biosecurity measures when considering translocation of wild ruminant species susceptible to BTV and EHDV. [less ▲]Detailed reference viewed: 47 (3 ULg)
Bluetongue Virus RNA Detection by Real-Time RT-PCR in Post-Vaccination Samples from Cattle
; Garigliany, Mutien-Marie ; et al
Conference (2013, October 02)Detailed reference viewed: 12 (1 ULg)
The presence of bluetongue virus serotype 8 RNA in Belgian cattle since 2008.
Garigliany, Mutien-Marie ; Desmecht, Daniel ;
in Transboundary and Emerging Diseases (2011), 58(6), 503-509
After a short winter break, bluetongue virus serotype 8 was responsible in 2007 for a large-scale epidemic among ruminant populations in Western Europe. Little is known about the mechanisms allowing the ... [more ▼]
After a short winter break, bluetongue virus serotype 8 was responsible in 2007 for a large-scale epidemic among ruminant populations in Western Europe. Little is known about the mechanisms allowing the virus to survive winter conditions. A yearly mass vaccination of cattle and sheep started in spring 2008, which was recognized as successful in terms of clinical protection, but occult circulation of the bluetongue virus has not been adequately addressed. We studied the carriage of bluetongue RNA in the spleen of cattle in the vector-free period and the circulation of bluetongue virus in cattle populations in Belgium since the introduction of vaccination programmes. Overall, the results presented here show evidence for the long-term carriage of bluetongue virus RNA in the spleen of cattle and demonstrated a low but significant circulation and transplacental transmission of bluetongue virus in Belgian cattle in 2009, with apparent disappearance in 2010. [less ▲]Detailed reference viewed: 17 (2 ULg)
The impact of naturally-occurring, trans-placental bluetongue virus serotype-8 infection on reproductive performance in sheep.
Saegerman, Claude ; ; et al
in Veterinary Journal (2011), 187(1), 72-80
Infection with bluetongue virus serotype (BTV)-8 occurred in ruminants in 2006 in Central-Western Europe. The trans-placental passage of this virus has been demonstrated in naturally- and experimentally ... [more ▼]
Infection with bluetongue virus serotype (BTV)-8 occurred in ruminants in 2006 in Central-Western Europe. The trans-placental passage of this virus has been demonstrated in naturally- and experimentally-infected cattle and in experimentally-infected sheep. Trans-placental transmission is potentially important in the 'over-wintering' of this virus and its subsequent impact on reproductive performance. This epidemiological study was carried out on a sheep flock in Belgium that had experienced a severe outbreak of BTV-8 infection, and where the seroprevalence had increased from 1.3% to 88% between January and November 2007. In total, 476 lambs and 26 aborted fetuses from 300 ewes, lambing at four distinct time periods, were investigated between November 2007 and May 2008. The following evidence suggested that BTV-8 infection occurred in utero: (1) positive PCR results from splenic tissue from aborted fetuses (n=4); (2) fetal malformations suggestive of BTV infection (n=10); (3) positive PCR results from red blood cells in-lambs (n=7), and (4) the presence of antibody at birth in viable lambs prior to the intake of colostrum (n=9). The evidence provided by this investigation strongly suggests that trans-placental BTV-8 infection occurs in naturally-infected sheep and the impact of infection on the reproductive performance of such a naive flock was considerable, with up to 25% of ewes aborting and with flock fertility reduced by 50%. The contribution of in utero-infected lambs to the over-wintering of BTV appears limited. [less ▲]Detailed reference viewed: 124 (30 ULg)
The most likely time and place of introduction of BTV8 into belgian ruminants
Saegerman, Claude ; ; Uyttenhoef, Aude et al
in PLoS ONE (2010), 5(2),Detailed reference viewed: 26 (16 ULg)
Modulating mouse innate immunity to RNA viruses by expressing the Bos taurus Mx system.
Garigliany, Mutien-Marie ; Cloquette, Karine ; et al
in Transgenic Research (2009), 18(5), 719-32
Mx proteins are interferon-induced members of the dynamin superfamily of large guanosine triphosphatases. These proteins have attracted much attention because some display antiviral activity against ... [more ▼]
Mx proteins are interferon-induced members of the dynamin superfamily of large guanosine triphosphatases. These proteins have attracted much attention because some display antiviral activity against pathogenic RNA viruses, such as members of the orthomyxoviridae, bunyaviridae, and rhabdoviridae families. Among the diverse mammalian Mx proteins examined so far, we have recently demonstrated in vitro that the Bos taurus isoform 1 (boMx1) is endowed with exceptional anti-rabies-virus activity. This finding has prompted us to seek an appropriate in vivo model for confirming and evaluating gene therapy strategies. Using a BAC transgene, we have generated transgenic mouse lines expressing the antiviral boMx1 protein and boMx2 proteins under the control of their natural promoter and short- and long-range regulatory elements. Expressed boMx1 and boMx2 are correctly assembled, as deduced from mRNA sequencing and western blotting. Poly-I/C-subordinated expression of boMx1 was detected in various organs by immunohistochemistry, and transgenic lines were readily classified as high- or low-expression lines on the basis of tissue boMx1 concentrations measured by ELISA. Poly-I/C-induced Madin-Darby bovine kidney cells, bovine turbinate cells, and cultured cells from high-expression line of transgenic mice were found to contain about the same concentration of boMx1, suggesting that this protein is produced at near-physiological levels. Furthermore, insertion of the bovine Mx system rendered transgenic mice resistant to vesicular-stomatitis-virus-associated morbidity and mortality, and embryonic fibroblasts derived from high-expression transgenic mice were far less permissive to the virus. These results demonstrate that the Bos taurus Mx system is a powerful anti-VSV agent in vivo and suggest that the transgenic mouse lines generated here constitute a good model for studying in vivo the various antiviral functions-known and yet to be discovered-exerted by bovine Mx proteins, with priority emphasis on the antirabic function of boMx1. [less ▲]Detailed reference viewed: 61 (13 ULg)
Experimental reproduction of bluetongue virus serotype 8 clinical disease in calves.
Dal Pozzo, Fabiana ; ; Guyot, Hugues et al
in Veterinary Microbiology (2009), 136(3-4), 352-8
Cattle are commonly subclinically infected following natural or experimental infection with bluetongue virus (BTV). The introduction of BTV serotype 8 (BTV-8) in Europe has been characterized by the ... [more ▼]
Cattle are commonly subclinically infected following natural or experimental infection with bluetongue virus (BTV). The introduction of BTV serotype 8 (BTV-8) in Europe has been characterized by the manifestation of clinical signs in infected cattle. In order to study the pathogenesis of BTV-8 in this host, an animal model able to reproduce the clinical manifestations of the disease is required. In this work, two calves were subcutaneously and intravenously injected with a low passage cell-adapted strain of BTV-8. Both calves showed typical bluetongue clinical signs, including pyrexia, ocular discharge, conjunctivitis, oral mucosal congestion, development of ulcers and necrotic lesions on the lips and tongue, submandibular oedema, coronitis and oedema of the coronet and pastern region. A score was assigned depending on the severity of the lesions and a total clinical score was calculated for each animal daily and at the end of the experiment. Both calves became viraemic 24h post-infection and seroconversion occurred between 7 and 11 days P.I. In this study we present the development of a protocol of infection in calves able to reproduce the severity of the lesions observed with BTV-8 in field conditions. [less ▲]Detailed reference viewed: 110 (28 ULg)
Bluetongue in captive yaks.
Mauroy, Axel ; Guyot, Hugues ; et al
in Emerging Infectious Diseases (2008), 14(4), 675-6
In August 2006, several Northern European countries including Belgium reported their first cases of bluetongue (BT). Surprisingly, it was the first time that BT was diagnosed so far in the northern ... [more ▼]
In August 2006, several Northern European countries including Belgium reported their first cases of bluetongue (BT). Surprisingly, it was the first time that BT was diagnosed so far in the northern hemisphere (1). BT is a non contagious, arthropod borne animal disease. The causal virus belongs to the genus Orbivirus in the family Reoviridae. The genome of the bluetongue virus (BTV) consists of 10 segments of double-stranded RNA and 24 serotypes have been reported (2). Serotype 8 (BTV-8) was implied in the emergence in Belgium (3). All ruminant species are thought to be susceptible to BT (2) but lack of data remains for certain species. We report here laboratory confirmed clinical cases of BT in yaks. [less ▲]Detailed reference viewed: 40 (9 ULg)
Conditional expression of type I interferon-induced bovine Mx1 GTPase in a stable transgenic vero cell line interferes with replication of vesicular stomatitis virus
Baise, Etienne ; ; et al
in Journal of Interferon & Cytokine Research (2004), 24(9), 513-521
In some vertebrate species, type I interferon(IFN)-induced Mx gene expression has been shown to confer resistance to some single-stranded RNA (ssRNA) viruses in vitro. Because the bovine species is ... [more ▼]
In some vertebrate species, type I interferon(IFN)-induced Mx gene expression has been shown to confer resistance to some single-stranded RNA (ssRNA) viruses in vitro. Because the bovine species is subject to an exceptionally wide array of infections caused by such viruses, it is anticipated that an antiviral allele should have been retained by evolution at the bovine Mx locus. The identification of such allele may help in evaluating the real significance of the Mx genotype for disease resistance in vivo, in deciphering host-virus molecular interactions involved, or in improving innate disease resistance of livestock through marker-assisted selection. We validated a double transgenic Vero cell clone in which the bovine Mx1 reference allele is placed under control of the human cytomegalovirus (CMV) enhancer-promoter sequence containing elements from the bacterial tetracycline resistance operon to regulate transcription. In the selected clone, transgene repression was very tight, and derepression by doxycycline led to homogeneous 48-h duration expression of physiologic levels of bovine Mx1. Expression of the transgene caused a dramatic decrease in cytopathic efficiency and a 500-5000-fold yield reduction of the Indiana and New Jersey serotypes of vesicular stomatitis virus (VSV). To our knowledge, the transgenic clone developed here is the first ever reported that allows conditional expression of an Mx protein, thus providing a valuable tool for studying functions of Mx proteins in general and that of bovine Mx1 in particular. This latter may henceforward be included in the group of Mx proteins with authenticated anti-VSV activity, which offers new research avenues into the field of host-virus interactions. [less ▲]Detailed reference viewed: 53 (14 ULg)