- N. Bald-Blume (1)
- Lineke Begeman (1)
- J.H.W. Bergervoet (1)
- Yannick Blanchard (1)
- Andrew Brownlow (1)
- Anette Bøtner (1)
- Nicholas Davison (1)
- Brecht Devleesschauwer (1)
- Rik G. Herbes (1)
- Béatrice Grasland (1)
- Wim H.M. Poel van der (1)
- Jan Haelters (1)
- Sjoukje Hiemstra (1)
- Lonneke IJsseldijk (1)
- Jooske IJzer (1)
- Graham J. Belsham (1)
- Bjorn J.A. Berendsen (1)
- Antonio Lavazza (1)
- Sophie Le Poder (1)
- Davide Lelli (1)
- Mardik Leopold (1)
- E. Maiss (1)
- Erik Nordkvist (1)
- Nicolas Rose (1)
- Falko Steinbach (1)
- Bertel Strandbygaard (1)
- Norbert Velde van de (1)
- Frederik Widén (1)
- Tina Zuidema (1)
Development of a molecular assay for the detection of Cucumber mosaic virus and the discrimination of its subgroups I and II
Bald-Blume, N. ; Bergervoet, J.H.W. ; Maiss, E. - \ 2017
Journal of Virological Methods 243 (2017). - ISSN 0166-0934 - p. 35 - 43.
Cucumber mosaic virus - ELISA - Luminex xTAG - Molecular diagnostics
A nucleic acid based test for the detection of the economically important plant virus Cucumber mosaic virus (CMV) based on the Luminex xTAG technology was developed. This technology has the advantage of allowing the simultaneous detection of various targets. Applying this method, we prove the presence of CMV in general and differentiate between its two subgroups I and II for which significant differences concerning severity of symptoms and virulence have been reported. For the development of the test procedure the coat protein gene sequences of 29 CMV isolates were cloned, sequenced and classified into subgroups. Sequences from GenBank were used to design primers. Additionally, a subgroup specific ELISA was conducted for comparison. This work is part of a project which aims to develop a test for the simultaneous detection of various plant pathogens (viral, bacterial and fungal) in plant material.
Toxoplasma gondii in stranded marine mammals from the North Sea and Eastern Atlantic Ocean : Findings and diagnostic difficulties
Velde, Norbert van de; Devleesschauwer, Brecht ; Leopold, Mardik ; Begeman, Lineke ; IJsseldijk, Lonneke ; Hiemstra, Sjoukje ; IJzer, Jooske ; Brownlow, Andrew ; Davison, Nicholas ; Haelters, Jan - \ 2016
Veterinary Parasitology 230 (2016). - ISSN 0304-4017 - p. 25 - 32.
ELISA - IFA - Marine mammals - MAT - PCR - Seroprevalence - Toxoplasma gondii
The occurrence of the zoonotic protozoan parasite Toxoplasma gondii in marine mammals remains a poorly understood phenomenon. In this study, samples from 589 marine mammal species and 34 European otters (Lutra lutra), stranded on the coasts of Scotland, Belgium, France, The Netherlands and Germany, were tested for the presence of T. gondii. Brain samples were analysed by polymerase chain reaction (PCR) for detection of parasite DNA. Blood and muscle fluid samples were tested for specific antibodies using a modified agglutination test (MAT), a commercial multi-species enzyme-linked immunosorbent assay (ELISA) and an immunofluorescence assay (IFA). Out of 193 animals tested by PCR, only two harbour porpoise (Phocoena phocoena) cerebrum samples, obtained from animals stranded on the Dutch coast, tested positive. The serological results showed a wide variation depending on the test used. Using a cut-off value of 1/40 dilution in MAT, 141 out of 292 animals (41%) were positive. Using IFA, 30 out of 244 tested samples (12%) were positive at a 1/50 dilution. The commercial ELISA yielded 7% positives with a cut-off of the sample-to-positive (S/P) ratio ≥ 50; and 12% when the cut-off was set at S/P ratio ≥ 20. The high number of positives in MAT may be an overestimation due to the high degree of haemolysis of the samples and/or the presence of lipids. The ELISA results could be an underestimation due to the use of a multispecies conjugate. Our results confirm the presence of T. gondii in marine mammals in The Netherlands and show exposure to the parasite in both the North Sea and the Eastern Atlantic Ocean. We also highlight the limitations of the tests used to diagnose T. gondii in stranded marine mammals.
Inter-laboratory study to characterize the detection of serum antibodies against porcine epidemic diarrhoea virus
Strandbygaard, Bertel ; Lavazza, Antonio ; Lelli, Davide ; Blanchard, Yannick ; Grasland, Béatrice ; Poder, Sophie Le ; Rose, Nicolas ; Steinbach, Falko ; Poel, Wim H.M. van der; Widén, Frederik ; Belsham, Graham J. ; Bøtner, Anette - \ 2016
Veterinary Microbiology 197 (2016). - ISSN 0378-1135 - p. 151 - 160.
ELISA - PEDV - Porcine coronavirus - Ring trial - Serology
Porcine epidemic diarrhea virus (PEDV) has caused extensive economic losses to pig producers in many countries. It was recently introduced, for the first time, into North America and outbreaks have occurred again in multiple countries within Europe as well. To assess the properties of various diagnostic assays for the detection of PEDV infection, multiple panels of porcine sera have been shared and tested for the presence of antibodies against PEDV in an inter-laboratory ring trial. Different laboratories have used a variety of “in house” ELISAs and also one commercial assay. The sensitivity and specificity of each assay has been estimated using a Bayesian analysis applied to the ring trial results obtained with the different assays in the absence of a gold standard. Although different characteristics were found, it can be concluded that each of the assays used can detect infection of pigs at a herd level by either the early European strains of PEDV or the recently circulating strains (INDEL and non-INDEL). However, not all the assays seem suitable for demonstrating freedom from disease in a country. The results from individual animals, especially when the infection has occurred within an experimental situation, show more variation.
Occurrence of chloramphenicol in cereal straw in north-western Europe
Nordkvist, Erik ; Zuidema, Tina ; Herbes, Rik G. ; Berendsen, Bjorn J.A. - \ 2016
Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment 33 (2016)5. - ISSN 1944-0049 - p. 798 - 803.
animal feed - bedding - Chloramphenicol - ELISA - LC-MS/MS - straw - survey
Two surveys are presented of straw analysed for naturally occurring chloramphenicol (CAP), a drug banned for use in food-producing animals. In the first study, CAP was analysed by LC-MS/MS and detected in 37 out of 105 straw samples originating from the Netherlands, France, the UK, Germany and Denmark. The highest level found was 6.3 µg kg−1, the average 0.6 µg kg−1 and the median 0.2 µg kg−1. The second study included a method comparison between ELISA and LC-MS/MS and a survey of CAP in cereal straw sampled at farms in all areas of Sweden. A total of 215 samples were screened by ELISA and a subset of 26 samples was also analysed by LC-MS/MS. Fifty-four of the samples contained more than 1 µg kg−1 CAP and the highest level found was 32 µg kg−1 (confirmed by LC-MS/MS). The highest contents of CAP in this study were allocated to the Baltic sea coast in the south-eastern part of Sweden (the county of Skåne and the Baltic Sea isle of Gotland). These results indicate a high incidence of CAP in straw in north-west Europe and have a severe impact on the enforcement of European Union legislation.