Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2015
Abstract
Elevated nutrient concentrations in streams in the Norwegian agricultural landscape may occur due to faecal contamination. Escherichia coli (E. coli) has been used conventionally as an indicator of this contamination; however, it does not indicate the source of faecal origin. This work describes a study undertaken for the first time in Norway on an application of specific host-associated markers for faecal source tracking of water contamination. Real-time quantitative polymerase chain reaction (qPCR) on Bacteroidales host-specific markers was employed for microbial source tracking (MST) to determine the origin(s) of faecal water contamination. Four genetic markers were used: the universal AllBac (Bacteroidales) and the individual specific markers BacH (humans), BacR (ruminants) and Hor-Bac (horses). In addition, a pathogenicity test was carried out to detect the top seven Shiga toxin-producing E. coli (STEC) serogroups. The ratio between each individual marker and the universal one was used to: (1) normalise the markers to the level of AllBac in faeces, (2) determine the relative abundance of each specific marker, (3) develop a contribution profile for faecal water contamination and (4) elucidate the sources of contamination by highlighting the dominant origin(s). The results of the qPCR MST analyses indicated the actual contributions of humans and animals to faecal water contamination. The pathogenicity test revealed that water samples were STEC positive at a low level, which was in proportion to the concentration of the ruminant marker. The outcomes were verified statistically by coupling the findings of major contamination sources with observations in the field regarding local land use (residential or agricultural). Furthermore, clear correlations between the human marker and E. coli counts as well as the ruminant marker and STEC quantity in faecally contaminated water were observed. The results of this study have the potential to help identify sources of pollution for targeted mitigation of nutrient losses.
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Authors
Anne Kjersti Uhlen Jon Arne Dieseth Shiori Koga Ulrike Böcker Bernt Hoel James A Anderson Anette Aamodt MoldestadAbstract
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Authors
Karen A. Alexander Tavis Potts Shirra Freeman Dafna Israel Johan Johansen Demetris Kletou Marte Meland Danilo Pecorino Celine Rebours Marc Shorten Dror AngelAbstract
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Authors
Seyda Ozkan Bouda Vosough Ahmadi Helge Bonesmo Olav Østerås Alistair Stott Odd Magne HarstadAbstract
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Abstract
Replication of all positive-sense single-stranded RNA viruses occurs in specific structures in close association with cellular membranes. Targeting of the viral replication complex (RC) to the site of replication is mediated by the interaction of viral-encoded proteins and host factors. Electron microscope studies have shown that Poinsettia mosaic virus (PnMV, family Tymoviridae) infection is associated with the presence of vesicular structures in the chloroplasts, which indicates that the replication of PnMV might occur in association with chloroplast-derived membranes. Using computer assisted homology search, we have identified that the coat protein (CP) of PnMV shows similarity to membrane bound proteins and contains a conserved amino acid sequence motif found in members of the Alb3/Oxa1/YidC protein family. This protein family is involved in the insertion of proteins into intracellular membranes. In this study we carried out localization studies combined with confocal laser microscopy to identify the cellular localization of the PnMV CP. Transient expression of red fluorescent protein (RFP)-tagged PnMV CP in Nicotiana benthamiana protoplast was shown to localize in the chloroplast.
Authors
Kari-Anne Lyng Ingunn Saur Modahl Hanne Møller John Morken Tormod Briseid Ole Jørgen HanssenAbstract
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Authors
Andrew N. Sharpley Lars Bergström Helena Aronsson Marianne Bechmann Carl Bolster Katarina Börling Faruk Djodjic Helen P. Jarvie Oscar F. Schoumans Christian Stamm Karin S. Tonderski Barbro Ulen Risto Uusitalo Paul J. A. WithersAbstract
No abstract has been registered