Ole Andreas Løchen Økstad

Image of Ole Andreas Løchen Økstad
Norwegian version of this page
Phone +47-22854789
Mobile phone +47-92603952
Room 252 ZEB Building (BL21)
Username
Visiting address Pharmacy Building (BL25) Sem Sælandsvei 3 0316 Oslo
Postal address Postboks 1068 Blindern 0316 OSLO
Other affiliations School of Pharmacy

Academic Interests

Investigating the regulatory mechanisms and the molecular basis for microbial biofilm formation in Bacillus cereus group bacteria. Roles of membrane transporters, including multidrug resistance proteins, in biofilm formation. Microbial genome studies, primarily of pathogenic (disease-causing) bacteria belonging to the Bacillus cereus group, including repeated and mobile elements and global transcriptional profiling.

Higher education and employment history

  • Professor, University of Oslo, 2015-present
  • Associate professor, University of Oslo 2005-2015
  • Sabbatical, Macquarie University, Sydney, Australia, 2011
  • Postdoc, University of Oslo, 2000-2002, 2002-2004
  • Visiting scientist, University of Oxford, England, 2001
  • Lab associate, Norwegian Defence Research Estsablishment (military service), 1999-2000
  • PhD, University of Oslo, 2000
  • Master of Science (MSc), University of Oslo, 1995
  • Bachelor of Science (BSc), University of Oslo, 1992

Teaching

I teach the following subjects in the five year pharmacy masters curriculum:

Appointments

  • Vice head, Centre for Integrative Microbial Evolution (CIME), Top Tier research environment at the Faculty of Mathematics and Natural Sciences, UiO 
  • Member of committees (user group, thematic groups for research lab space and office space) for the new LifeScience building, UiO campus
  • Head of subject FRM2040, School of Pharmacy
  • Member of CLSi Reference group, Computational Life Science, UiO

 Collaborators

CV

  • For more information, please see my CV
Tags: Microbiology, Life science, Bioinformatics, Molecular biology, Evolution, Biotechnology, Biology, Genomes, DNA sequencing, Biofilm, Food poisoning

Publications

Read TD, Peterson SN, Tourasse N, Baillie LW, Paulsen IT, Nelson KE, Tettelin H, Fouts DE, Eisen JA, Gill SR, Holtzapple EK, Økstad OA, Helgason E, et al. (2003). The genome sequence of Bacillus anthracis Ames and comparison to closely related bacteria. Nature 423(6935):81-6.

Kristoffersen SM, Haase C, Weil MR, Passalacqua KD, Niazi F, Hutchison SK, Desany B, Kolstø AB, Tourasse NJ, Read TD, Økstad OA (2012). Global mRNA decay analysis at single nucleotide resolution reveals segmental and positional degradation patterns in a Gram-positive bacterium. Genome Biology 13(4):R30.

 

Kristoffersen SM, Tourasse NJ, Kolstø AB, Økstad OA (2010). Interspersed DNA repeats bcr1-bcr18 of Bacillus cereus group bacteria form three distinct groups with different evolutionary and functional patterns. Mol Biol Evol. 28, 963-983.

Fagerlund A, Dubois T, Økstad OA, Gilois N, Bennaceur I, Perchat S, Gominet M, Aymerich S, Kolstø AB, Lereclus D, Gohar M (2014). SinR controls enterotoxin expression in Bacillus cereus biofilms. PLoS One9(1):e87532.

Kolstø AB, Tourasse NJ, Økstad OA (2009). What sets Bacillus anthracis apart from other Bacillus species? Annu Rev Microbiol. 63:451-76.

Gohar M, Faegri K, Perchat S, Ravnum S, Økstad OA, Gominet M, Kolstø AB, Lereclus D (2008). The PlcR virulence regulon of Bacillus cereus. PLoS One. 30;3(7):e2793.

Papazisi L, Rasko DA, Ratnayake S, Bock GR, Remortel BG, Appalla L, Liu J, Dracheva T, Braisted JC, Shallom S, Jarrahi B, Snesrud E, Ahn S, Sun Q, Rilstone J, Økstad OA, Kolstø AB, Fleischmann RD, Peterson SN (2011). Investigating the genome diversity of B. cereus and evolutionary aspects of B. anthracis emergence. Genomics 98(1):26-39. doi: 10.1016/j.ygeno.2011.03.008.

Klevan A, Tourasse NJ, Stabell FB, Kolstø AB, Økstad OA. Exploring the evolution of the Bacillus cereus group repeat element bcr1 by comparative genome analysis of closely related strains. Microbiology SGM. 2007 153(Pt 11):3894-908.

Rasko DA, Rosovitz MJ, Økstad OA, Fouts DE, Jiang L, Cer RZ, Kolstø AB, Gill SR, Ravel J. Complete sequence analysis of novel plasmids from emetic and periodontal Bacillus cereus isolates reveals a common evolutionary history among the B. cereus-group plasmids, including Bacillus anthracis pXO1. J Bacteriol. 2007 189(1):52-64.

Rasko DA, Ravel J, Økstad OA, Helgason E, Cer RZ, Jiang L, Shores KA, Fouts DE, Tourasse NJ, Angiuoli SV, Kolonay J, Nelson WC, Kolstø AB, Fraser CM, Read TD. The genome sequence of Bacillus cereus ATCC 10987 reveals metabolic adaptations and a large plasmid related to Bacillus anthracis pXO1. Nucleic Acids Res. 2004 32(3):977-88.

Økstad OA, Tourasse NJ, Stabell FB, Sundfaer CK, Egge-Jacobsen W, Risøen PA, Read TD, Kolstø AB. The bcr1 DNA repeat element is specific to the Bacillus cereus group and exhibits mobile element characteristics. J Bacteriol. 2004186(22):7714-25.
 

 

  • Fagerlund, Annette; Smith, Veronika; Kjendseth, Åsmund Røhr; Lindbäck, Toril; Parmer, Marthe Petrine; Andersson, K. Kristoffer; Reubsaet, Leon & Økstad, Ole Andreas Løchen (2016). Cyclic diguanylate regulation of Bacillus cereus group biofilm formation. Molecular Microbiology.  ISSN 0950-382X.  101(3), s 471- 494 . doi: 10.1111/mmi.13405
  • Fagerlund, Annette; Dubois, Thomas; Økstad, Ole Andreas Løchen; Verplaetse, Emilie; Gilois, Nathalie; Bennaceur, Imene; Perchat, Stephane; Gominet, Myriam; Aymerich, Stephane; Kolstø, Anne-Brit; Lereclus, Didier & Gohar, Michel (2014). SinR controls enterotoxin expression in Bacillus thuringiensis biofilms. PLoS ONE.  ISSN 1932-6203.  9(1) . doi: 10.1371/journal.pone.0087532
  • Vörös, Aniko; Simm, Roger; Slamti, Leyla; McKay, Matthew J.; Hegna, Ida Kristin; Nielsen-Leroux, Christina; Hassan, Karl A.; Paulsen, Ian T.; Lereclus, Didier; Økstad, Ole Andreas Løchen; Molloy, Mark P. & Kolstø, Anne-Brit (2014). SecDF as part of the sec-translocase facilitates efficient secretion of Bacillus cereus toxins and cell wall-associated proteins. PLoS ONE.  ISSN 1932-6203.  9:e0103326(8) . doi: 10.1371/journal.pone.0103326
  • Backe, Paul Hoff; Simm, Roger; Lærdahl, Jon Kristen; Dalhus, Bjørn; Fagerlund, Annette; Økstad, Ole Andreas Løchen; Rognes, Torbjørn; Alseth, Ingrun; Kolstø, Anne-Brit & Bjørås, Magnar (2013). A new family of proteins related to the HEAT-like repeat DNA glycosylases with affinity for branched DNA structures. Journal of Structural Biology.  ISSN 1047-8477.  183(1), s 66- 75 . doi: 10.1016/j.jsb.2013.04.007 Full text in Research Archive
  • Bräunlich, Paula Marie; Økstad, Ole Andreas Løchen; Slimestad, Rune; Wangensteen, Helle; Malterud, Karl Egil & Barsett, Hilde (2013). Effects of Aronia melanocarpa constituents on biofilm formation of Escherichia coli and Bacillus cereus. Molecules.  ISSN 1420-3049.  18(12), s 14989- 14999 . doi: 10.3390/molecules181214989
  • Vik, Unni; Logares, Ramiro; Blaalid, Rakel; Halvorsen, Rune; Carlsen, Tor; Bakke, Ingrid; Kolstø, Anne-Brit; Økstad, Ole Andreas Løchen & Kauserud, Håvard (2013). Different bacterial communities in ectomycorrhizae and surrounding soil. Scientific Reports.  ISSN 2045-2322.  3(347) . doi: 10.1038/srep03471 Full text in Research Archive
  • Kristoffersen, Simen Martens; Haase, Chad; Weil, M. Ryan; Passalacqua, Karla D.; Niazi, Fahim; Hutchison, Stephen; Desany, Brian; Kolstø, Anne-Brit; Tourasse, Nicolas; Read, Timothy D. & Økstad, Ole Andreas Løchen (2012). Global mRNA decay analysis at single nucleotide resolution reveals segmental and positional degradation patterns in a Gram-positive bacterium. Genome Biology.  ISSN 1465-6906.  13(4) . doi: 10.1186/gb-2012-13-4-r30
  • Kristoffersen, Simen Martens; Tourasse, Nicolas; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2011). Interspersed DNA Repeats bcr1-bcr18 of Bacillus cereus Group Bacteria Form Three Distinct Groups with Different Evolutionary and Functional Patterns. Molecular biology and evolution.  ISSN 0737-4038.  28(2), s 963- 983 . doi: 10.1093/molbev/msq269
  • Papazisi, Leka; Rasko, David A.; Ratnayake, Shashikala; Bock, Geoff R.; Remortel, Brian G.; Appalla, Lakshimi; Liu, Jia; Dracheva, Tatiana; Braisted, John C.; Shallom, Shamira; Jarrahi, Behnam; Snesrud, Erik; Ahn, Susie; Sun, Qiang; Rilstone, Jennifer; Økstad, Ole Andreas Løchen; Kolstø, Anne-Brit; Fleischmann, Robert D. & Peterson, Scott N. (2011). Investigating the genome diversity of B. cereus and evolutionary aspects of B. anthracis emergence. Genomics.  ISSN 0888-7543.  98(1), s 26- 39 . doi: 10.1016/j.ygeno.2011.03.008
  • Reiter, Lillian; Tourasse, Nicolas; Fouet, Agnes; Loll, Raphaël; Davison, Sophie; Økstad, Ole Andreas Løchen; Piehler, Armin & Kolstø, Anne-Brit (2011). Evolutionary History and Functional Characterization of Three Large Genes Involved in Sporulation in Bacillus cereus Group Bacteria. Journal of Bacteriology.  ISSN 0021-9193.  193(19), s 5420- 5430 . doi: 10.1128/JB.05309-11
  • Tourasse, Nicolas; Helgason, Erlendur; Klevan, Leif Are; Sylvestre, Patricia; Moya, Maryse; Haustant, Michel; Økstad, Ole Andreas Løchen; Fouet, Agnes; Mock, Michele & Kolstø, Anne-Brit (2011). Extended and global phylogenetic view of the Bacillus cereus group population by combination of MLST, AFLP, and MLEE genotyping data. Food microbiology (Print).  ISSN 0740-0020.  28(2), s 236- 244 . doi: 10.1016/j.fm.2010.06.014
  • Tourasse, Nicolas; Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2010). HyperCAT: an extension of the SuperCAT database for global multi-scheme and multi-datatype phylogenetic analysis of the Bacillus cereus group population. Database: The Journal of Biological Databases and Curation.  ISSN 1758-0463.
  • Kolstø, Anne-Brit; Tourasse, Nicolas & Økstad, Ole Andreas Løchen (2009). What Sets Bacillus anthracis Apart from Other Bacillus Species?. Annual Review of Microbiology.  ISSN 0066-4227.  63, s 451- 476 . doi: 10.1146/annurev.micro.091208.073255
  • Stabell, Fredrik Bernhard; Jacobsen, Wolfgang Mathias; Risøen, Per Arne; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2009). ORF 2 from the Bacillus cereus linear plasmid pBClin15 encodes a DNA binding protein. Letters in Applied Microbiology.  ISSN 0266-8254.  48(1), s 51- 57 . doi: 10.1111/j.1472-765X.2008.02483.x
  • Gohar, Michel; Fægri, Karoline; Perchat, Stephane; Ravnum, Solveig; Økstad, Ole Andreas Løchen; Gominet, Myriam; Kolstø, Anne-Brit & Lereclus, Didier (2008). The PlcR Virulence Regulon of Bacillus cereus. PLoS ONE.  ISSN 1932-6203.  3(7), s e2793 . doi: 10.1371/journal.pone.0002793
  • Klevan, Leif Are; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2007). Exploring the evolution of the Bacillus cereus group repeat element bcr1 by comparative genome analysis of closely related strains. Microbiology.  ISSN 1350-0872.  153, s 3894- 3908 . doi: 10.1099/mic.0.2007/005504-0
  • Kristoffersen, Simen Martens; Ravnum, Solveig; Tourasse, Nicolas; Økstad, Ole Andreas Løchen; Kolstø, Anne-Brit & Davies, William (2007). Low concentrations of bile salts induce stress responses and reduce motility in Bacillus cereus ATCC 14570 . Journal of Bacteriology.  ISSN 0021-9193.  189(14), s 5302- 5313 . doi: 10.1128/JB.00239-07
  • Rasko, DA; Rosovitz, MJ; Økstad, Ole Andreas Løchen; Fouts, DE; Jiang, LX; Cer, RZ; Kolstø, Anne-Brit; Gill, SR & Ravel, J (2007). Complete sequence analysis of novel plasmids from emetic and periodontal Bacillus cereus isolates reveals a common evolutionary history among the B-cereus-group plasmids, including Bacillus anthracis pXO1. Journal of Bacteriology.  ISSN 0021-9193.  189(1), s 52- 64 . doi: 10.1128/JB.01313-06
  • Tourasse, Nicolas; Helgason, Erlendur; Økstad, Ole Andreas Løchen; Hegna, Ida Kristin & Kolstø, Anne-Brit (2006). The Bacillus cereus group: novel aspects of population structure and genome dynamics. Journal of Applied Microbiology.  ISSN 1364-5072.  101, s 579- 593
  • Rasko, David A; Ravel, Jacques; Økstad, Ole Andreas Løchen; Helgason, Erlendur; Cer, Regina; Jiaug, L; Shores, KA; Fouts, D; Tourasse, Nicolas; Augiuoli, SV; Kolonay, J; Nelson, WC; Kolstø, Anne-Brit; Fraser, CM & Read, Timothy D. (2004). The genome sequence of Bacillus cereus ATCC 10987 reveals metabolic adaptations and a large plasmid related to Bacillus anthracis pXO1. Nucleic Acids Research.  ISSN 0305-1048.  32(3), s 977- 988
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Sundfær, Cathrine Kleven; Jacobsen, Wolfgang Mathias; Risøen, Per Arne; Read, TD & Kolstø, Anne-Brit (2004). The bcr1 DNA repeat element is specific to the Bacillus cereus group and exhibits mobile element characteristics. Journal of Bacteriology.  ISSN 0021-9193.  186(22), s 7714- 7725
  • Read, Timothy D.; Peterson, Scott N.; Tourasse, Nicolas; Baillie, L. W.; Paulsen, I. W.; Nelson, K. E.; Tettelin, H.; Fouts, D. E.; Eisen, J. A.; Gill, S. A.; Holtzapple, E. K.; Økstad, Ole Andreas Løchen; Helgason, Erlendur; Rilstone, Jennifer; Wu, M.; Kolonay, J. F.; Beanan, M. J.; Dodson, R. J.; Brinkac, L. M.; Gwinn, M.; Boy, R T De; Madpu, R.; Daugherty, S. C.; Durkin, A. S.; Haft, D. H.; Nelson, W. C.; Peterson, John; Pop, M.; Khouri, H. M.; Radune, D.; Benton, J. L.; Mahamoud, Y.; Jiang, L.; Hance, I. R.; Weidman, J. F.; Berry, K. J.; Plaut, R. D.; Wolf, A. M.; Watkins, K. L.; Nierman, W. C.; Hazen, Alison; Cline, D.; Redmond, C.; Thwaite, J. E.; White, O.; Salzberg, S. L.; Thomason, B.; Friedlander, A. M.; Koehler, T. M.; Hanna, P. C.; Kolstø, Anne-Brit & Fraser, C. M. (2003). The genome sequence of Bacillus anthracis Ames and comparison to closely related bacteria. Nature.  ISSN 0028-0836.  423, s 81- 86
  • Gohar, Michel; Økstad, Ole Andreas Løchen; Gilois, N.; Sanchis, Vincent; Kolstø, Anne-Brit & Lereclus, Didier (2002). Two-dimensional electrophoresis analysis of the extracellular proteome of Bacillus cereus reveals the importance of the PlcR regulon. Proteomics.  ISSN 1615-9853.  2(6), s 784- 791
  • Helgason, Erlendur; Økstad, Ole Andreas Løchen; Caugant, Dominique A; Johansen, Henning A.; Fouet, Agnes; Mock, Michele; Hegna, Ida Kristin & Kolstø, Anne-Brit (2000). Bacillus anthracis, Bacillus cereus and Bacillus thuringiensis - one species based on genetic evidence. Applied and Environmental Microbiology.  ISSN 0099-2240.  66, s 2627- 2630
  • Kolstø, Anne-Brit; Helgason, Erlendur; Økstad, Ole Andreas Løchen; Caugant, Dominique A; Johansen, Henning A.; Fouet, Agnes; Mock, Michele & Hegna, Ida Kristin (2000). Bacillus anthracis, Bacillus cereus and Bacillus thuringiensis - one species on the basis of genetic evidence. Applied and Environmental Microbiology.  ISSN 0099-2240.  (66), s 2627- 2630
  • Alseth, I.; Lindbäck, Toril; Kristiansen, K. I.; Lillehagen, L.; Økstad, Ole Andreas Løchen; Bjørås, O.A.; Seeberg, Erling Christen & Kolstø, Anne-Brit (1999). Multiple pathways for excision repair of DNA alkylation damage in Bacillus species: Novel classes of 3-methyladenine DNA glycosylases from bacillus cereus. Molecular Microbiology.  ISSN 0950-382X.
  • Kolstø, Anne-Brit; Alseth, Ingrun; Lindbäck, Toril; Kristiansen, K. I.; Lillehagen, L.; Økstad, Ole Andreas Løchen; Bjørås, Magnar & Seeberg, Erling Christen (1999). Multiple pathways for excision repair of DNA alkylation daamage in Bacillus species: Novel classes of 3-methyladenine DNA glycosylases from Bacillus cereus. Molecular Microbiology.  ISSN 0950-382X.  (In revision.)
  • Kolstø, Anne-Brit; Lindbäck, Toril; Økstad, Ole Andreas Løchen & Rishovd, Anne-Lise (1999). Insertional inactivation of hblC encoding the L2-component of Bacillus cereus ATCC 14579 haemolysin BL strongly reduces enterotoxigenic activity, but not the haemolytic activity against human erythocytes. Microbiology.  ISSN 1350-0872.  145, s 3139- 3146

View all works in Cristin

  • Ho, Giang Thanh Thi; Braünlich, Marie; Økstad, Ole Andreas Løchen; Slimestad, Rune; Wangensteen, Helle; Malterud, Karl Egil & Barsett, Hilde (2015). Effects of Aronia melanocarpa on biofilm formation of Escherichia coli and Bacillus cereus.
  • Ho, Giang Thanh Thi; Braünlich, Marie; Wangensteen, Helle; Malterud, Karl Egil; Økstad, Ole Andreas Løchen; Christensen, Hege Staaland; Johannesen, Siri; Slimestad, Rune & Barsett, Hilde (2014). Spennende helseeffekter av aroniabær.
  • Røhr, Åsmund Kjendseth; Fagerlund, Annette; Økstad, Ole Andreas Løchen & Andersson, K. Kristoffer (2013). Characterization of a redox sensor involved in Bacillus cereus biofilm formation. NBS-nytt.  ISSN 0801-3535.  1, s 62- 62
  • Fagerlund, Annette; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2009). Differential gene expression and gene regulation during Bacillus thuringiensis biofilm formation.
  • Kolstø, Anne-Brit; Tourasse, Nicolas; Økstad, Ole Andreas Løchen; Fægri, Karoline & Fagerlund, Annette (2009). Bacillus cereus gene regulation and pathogenomics.
  • Kolstø, Anne-Brit; Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Kristoffersen, Simen Martens; Fægri, Karoline & Fagerlund, Annette (2009). Bacillus cereus group: genome plasticity for better adaptation.
  • Kristoffersen, Simen Martens; Tourasse, Nicolas; Bakka, Eirik Rødseth; Read, Timothy D.; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2009). Repeated DNA elements in the Bacillus cereus group - implications for genome dynamics and stability of messenger RNA.
  • Tourasse, Nicolas; Helgason, Erlendur; Klevan, Leif Are; Sylvestre, Patricia; Moya, Maryse; Haustant, Michel; Økstad, Ole Andreas Løchen; Fouet, Agnes; Mock, Michele & Kolstø, Anne-Brit (2009). Global multi-datatype phylogenetic analysis of the Bacillus cereus group reveals new lineages and clusters.
  • Økstad, Ole Andreas Løchen (2009). Differential gene expression and gene regulation during biofilm formation in Bacillus thuringiensis.
  • Økstad, Ole Andreas Løchen & Tourasse, Nicolas (2009). Genome dynamics in the Bacillus cereus group of bacteria: introns and repeats.
  • Klevan, Leif Are; Tourasse, Nicolas; Kristoffersen, Simen Martens; Langørgen, Heidi K.; Stabell, Fredrik Bernhard; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2008). Mobile chromosomal repeat elements in pathogenic Bacilli − comparative genomics of isolates closely related to Bacillus anthracis and co-transcription with neighbour genes.
  • Kristoffersen, Simen Martens; Klevan, Leif Are; Tourasse, Nicolas; Langørgen, Heidi K.; Stabell, Fredrik Bernhard; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2008). The mobile chromosomal repeat element bcr1 from the Bacillus cereus group is co−transcribed with neighboring genes and predicted to fold into a double hairpin−like structure.
  • Kristoffersen, Simen Martens; Tourasse, Nicolas; Klevan, Leif Are; Bakka, Eirik Rødseth; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2008). The Mobile Chromosomal Repeat Element bcr1in Bacillus cereus Stabilizes Adjacent mRNAs.
  • Tourasse, Nicolas; Økstad, Ole Andreas Løchen; Stabell, Fredrik Bernhard; Kristoffersen, Simen Martens & Kolstø, Anne-Brit (2008). Genome dynamics in Bacillus cereus − Bacillus anthracis − Bacillus thuringiensis.
  • Økstad, Ole Andreas Løchen (2008). Bacillus anthracis, B. cereus, and B. thuringiensis − pathogenic spore-forming bacteria ACTing out an identity crisis.
  • Økstad, Ole Andreas Løchen; Klevan, Leif Are; Tourasse, Nicolas; Kristoffersen, Simen Martens; Langørgen, Heidi K.; Stabell, Fredrik Bernhard & Kolstø, Anne-Brit (2008). Mobile chromosomal repeat elements in Bacillus cereus, B. thuringiensis, and B. anthracis − Comparative genomics and transcriptional analysis.
  • Økstad, Ole Andreas Løchen; Klevan, Leif Are; Tourasse, Nicolas; Kristoffersen, Simen Martens; Langørgen, Heidi K.; Stabell, Fredrik Bernhard & Kolstø, Anne-Brit (2008). Mobile chromosomal repeat elements in pathogenic bacilli − comparative genomics and transcriptional analysis.
  • Biørnstad, Truls Johan; Jensen, Christine; Gohar, Michel; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2007). Biofilm formation in Bacillus cereus group pathogens − screening of isolates and functional dissection of candidate genes potentially involved in the process.
  • Fægri, Karoline; Hegna, Ida Kristin; Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2007). Comparative analysis of global gene expression in Bacillus cereus ATCC 14579 and a deletion mutant of a membrane transporter with similarity to tetracycline resistance genes.
  • Fægri, Karoline; Ravnum, Solveig; Økstad, Ole Andreas Løchen; Tourasse, Nicolas & Kolstø, Anne-Brit (2007). Bruk av mikromatriser for å studere genregulering i Bacillus cereus.
  • Klevan, Are; Kristoffersen, Simen Martens; Langørgen, Heidi K.; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2007). THE MOBILE CHROMOSOMAL REPEAT ELEMENT BCR1 IN BACILLUS CEREUS, B. THURINGIENSIS AND B. ANTHRACIS.
  • Kristoffersen, Simen Martens; Ravnum, Solveig; Tourasse, Nicolas; Økstad, Ole Andreas Løchen; Kolstø, Anne-Brit & Davies, William (2007). Gene transcription responses to bile salts in Bacillus cereus ATCC 14579 – in vitro modeling of GI-tract bile exposure.
  • Kristoffersen, Simen Martens; Ravnum, Solveig; Tourasse, Nicolas; Økstad, Ole Andreas Løchen; Kolstø, Anne-Brit & Davies, William (2007). Low concentrations of bile salts induce stress responses and reduce motility in the Bacillus cereus type strain.
  • Økstad, Ole Andreas Løchen; Klevan, Are; Tourasse, Nicolas; Stabell, Fredrik Bernhard & Kolstø, Anne-Brit (2007). Mobile chromosomal repeat elements in Bacillus cereus, B. thuringiensis and B. anthracis.
  • Økstad, Ole Andreas Løchen; Klevan, Are; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Kristoffersen, Simen Martens & Kolstø, Anne-Brit (2007). Mobile chromosomal repeat elements unique to the Bacillus cereus group − chromosomal organization, transcription, and secondary structure.
  • Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2007). Bacillus ACT 2007 - Oslo, 17-21 June 2007. NBS-nytt.  ISSN 0801-3535.  (3), s 28- 30
  • Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2007). Mikrobiologi-konferanse i FI-regi. Norsk Farmaceutisk Tidsskrift.  ISSN 0029-1935.  (11), s 10- 10
  • Økstad, Ole Andreas Løchen; Ravel, Jacques; Rasko, David A; Rosovitz, MJ; Tourasse, Nicolas & Kolstø, Anne-Brit (2007). Comprehensive whole genome sequence analysis of clinical Bacillus cereus isolates from different human infections.
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Hegna, Ida Kristin & Kolstø, Anne-Brit (2007). Functional and comparative genomics in pathogenic Bacillus species.
  • Økstad, Ole Andreas Løchen (2006). Infeksjonssykdommenes retur - hva kan genomforskning på patogene bakterier fortelle oss?.
  • Biørnstad, Truls Johan; Jensen, Christine; Gohar, Michel; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2006). Screening for biofilm formation among bacteria from the Bacillus cereus group and dissection of candidate genes potentially involved in the process.
  • Biørnstad, Truls Johan; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2006). Screening for biofilm formation among bacteria from the Bacillus cereus group.
  • Fægri, Karoline; Ravnum, Solveig; Økstad, Ole Andreas Løchen; Tourasse, Nicolas & Kolstø, Anne-Brit (2006). Comparative analysis of global gene expression in Bacillus cereus ATCC 14579 and a derivative strain following gene deletion of delta-PlcR, a transcriptional regulator of extracellular virulence.
  • Fægri, Karoline; Ravnum, Solveig; Økstad, Ole Andreas Løchen; Tourasse, Nicolas & Kolstø, Anne-Brit (2006). Comparing wt Bacillus cereus with a transcriptional regulator mutant.
  • Klevan, Are; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Helgason, Erlendur; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2006). Genome dynamics in Bacillus cereus group pathogens - in silico experiments predict mobility of the bcr1 repeat element is related to RNA secondary structure stability.
  • Klevan, Leif Are; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2006). An evolutionary snapshot of the repeated element bcr1 in Bacillus cereus group strains close to the Bacillus anthracis cluster − transcription analysis, RNA folding, and traces of mobility.
  • Kristoffersen, Simen Martens; Ravnum, Solveig; Økstad, Ole Andreas Løchen; Kolstø, Anne-Brit & Davies, William (2006). Transcriptome analysis of bile salt treated Bacillus cereus ATCC 14579.
  • Tourasse, Nicolas; Helgason, Erlendur; Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2006). Novel aspects of population and genome dynamics in the Bacillus cereus group of bacterial pathogens.
  • Tourasse, Nicolas; Helgason, Erlendur; Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2006). The Bacillus cereus group: novel aspects of population structure and genome dynamics.
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Rasko, David A; Meisal, Roger; Helgason, Erlendur; Kolstø, Anne-Brit; Papasizi, Leka & Peterson, Scott N. (2006). Gene discovery by comparative genome hybridization (GDCGH) − investigating gene diversity in the Bacillus cereus group of bacterial pathogens.
  • Klevan, Leif Are; Tourasse, Nicolas; Helgason, Erlendur; Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2005). Distribution, evolution and possible mobility of the repeated element bcr1 by examination of Bacillus cereus group strains from the B. anthracis cluster.
  • Klevan, Leif Are; Tourasse, Nicolas; Helgason, Erlendur; Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2005). Repeated element bcr1 from the Bacillus cereus group: Distribution, evolution and possible mobility in a set of strains closely related to B. anthracis.
  • Klevan, Leif Are; Tourasse, Nicolas; Helgason, Erlendur; Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2005). The repeated element bcr1: Distribution, evolution and possible mobility in the Bacillus cereus group of bacteria.
  • Klevan, Leif Are; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Helgason, Erlendur; Kolstø, Anne-Brit & Økstad, Ole Andreas Løchen (2005). Exploring the phylogeny of Bacillus cereus strains close to the B. anthracis cluster through distribution and sequence analysis of the repeated element bcr1.
  • Økstad, Ole Andreas Løchen (2004). Hva skiller en vanlig matforgiftningsbakterie fra en akutt dødelig bakterie - djevelen er i detaljene.
  • Økstad, Ole Andreas Løchen; Helgason, Erlendur; Tourasse, Nicolas & Kolstø, Anne-Brit (2004). Whole genome sequencing reveals unexpected similarities between a Bacillus cereus dairy isolate and highly virulent Bacillus anthracis, the cause of anthrax.
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Sundfær, Cathrine Kleven; Klevan, Are; Risøen, Per Arne; Read, Timothy D. & Kolstø, Anne-Brit (2004). Comparative genome analysis of pathogenic Bacilli – the bcr1 DNA repeat is specific to the Bacillus cereus group and exhibits mobile lement characteristics.
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Stabell, Fredrik Bernhard; Sundfær, Cathrine Kleven; Klevan, Are; Risøen, Per Arne; Read, Timothy D. & Kolstø, Anne-Brit (2004). bcr1, a novel mobile element specific to the Bacillus cereus group?.
  • Helgason, Erlendur; Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Read, Timothy D.; Peterson, Scott N. & Kolstø, Anne-Brit (2003). Plasmid variation versus chromosomal population structure of the Bacillus cereus group.
  • Risøen, Per Arne; Økstad, Ole Andreas Løchen; Hegna, Ida Kristin & Kolstø, Anne-Brit (2003). Characterization of a gene cluster putatively involved in the production of an antimicrobial substance in Bacillus cereus.
  • Stenmark, Harald Alfred; Tourasse, Nicolas; Økstad, Ole Andreas Løchen; Helgason, Erlendur & Kolstø, Anne-Brit (2003). Norsk forskningsgruppe deltar i avsløring av miltbrannbakteriens hemmeligheter. NBS-nytt.  ISSN 0801-3535.  (2), s 6- 6
  • Tourasse, Nicolas; Økstad, Ole Andreas Løchen; Helgason, Erlendur & Kolstø, Anne-Brit (2003, 05. juni). Anthrax-bakteriens gener . [TV].  NRK Schrødinger's Katt.
  • Tourasse, Nicolas; Økstad, Ole Andreas Løchen; Helgason, Erlendur; Rasko, David A; Read, Timothy D. & Kolstø, Anne-Brit (2003). Genetic and genomic comparison of members of the Bacillus cereus group of bacteria.
  • Økstad, Ole Andreas Løchen (2003). The B. cereus group of bacteria - not quite anthrax, but still interesting.
  • Økstad, Ole Andreas Løchen (2003). The Bacillus cereus group of bacteria � the good, the bad, and the ugly.
  • Økstad, Ole Andreas Løchen; Helgason, Erlendur; Tourasse, Nicolas; Rasko, David A; Ravel, Jacques; Read, Timothy D. & Kolstø, Anne-Brit (2003). Genome analysis of Bacillus cereus ATCC 10987 and comparison to Bacillus anthracis Ames.
  • Økstad, Ole Andreas Løchen; Read, Timothy D.; Risøen, Per Arne; Tourasse, Nicolas; Sundfær, Cathrine Kleven; Stabell, Fredrik Bernhard & Kolstø, Anne-Brit (2003). bcr1 � a novel repeated element specific to the B. cereus group of bacteria.
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Helgason, Erlendur & Kolstø, Anne-Brit (2003, 02. mai). Miltbrann: Norske forskere avslører terrorbakterie . [Internett].  TV2 Nettavisen.
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Helgason, Erlendur & Kolstø, Anne-Brit (2003, 01. juni). Miltbrannbakterien kartlagt.  Uniforum nr. 06/2003 (juni), p.4.
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Helgason, Erlendur & Kolstø, Anne-Brit (2003, 30. april). UiO-forskere i Nature - nærbilde av anthrax genomet . [Internett].  Apollon + science news on the web.
  • Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Sundfær, Cathrine Kleven; Stabell, Fredrik Bernhard; Risøen, Per Arne; Jacobsen, Wolfgang Mathias; Read, Timothy D. & Kolstø, Anne-Brit (2003). THE CHROMOSOMAL REPEAT ELEMENT BCR1 IS A SIGNATURE SEQUENCE TO THE BACILLUS CEREUS GROUP.
  • Økstad, Ole Andreas Løchen (2003). Bacillus anthracis og miltbrann.
  • Kolstø, Anne-Brit; Tourasse, Nicolas; Rilstone, Jennifer; Økstad, Ole Andreas Løchen; Helgason, Erlendur; Hazen, Alison; Read, Timothy D. & Peterson, Scott N. (2002). Genetic analysis of the Bacillus cereus group: Conservation of pXO1 Bacillus anthracis genes in Bacillus cereus plasmids.
  • Økstad, Ole Andreas Løchen (2002). Hva bakterienes arvestoff kan fortelle oss.
  • Økstad, Ole Andreas Løchen; Gohar, Michel; Lereclus, Didier; Sanchis, Vincent & Kolstø, Anne-Brit (2002). The global plcR virulence regulon from Bacillus cereus ¿ genomic and proteomic analysis.
  • Økstad, Ole Andreas Løchen; Sundfær, Cathrine Kleven & Kolstø, Anne-Brit (2002). A novel chromosomal repeat element bcr1 is common to the Bacillus cereus group of bacteria (including B. cereus, B. anthracis and B. thuringiensis).
  • Helgason, Erlendur; Økstad, Ole Andreas Løchen; Hegna, Ida Kristin; Bergan, Pål Andreas & Kolstø, Anne-Brit (2001). Genetic diversity of the Bacillus cereus group.
  • Helgason, Erlendur; Økstad, Ole Andreas Løchen; Tourasse, Nicolas; Read, Timothy D.; Peterson, Scott N. & Kolstø, Anne-Brit (2001). Plasmid variation versus chromosomal population structure of the B. cereus group.
  • Økstad, Ole Andreas Løchen; Gohar, Michel; Sanchis, Vincent; Lereclus, Didier & Kolstø, Anne-Brit (2001). Sequence and proteomic analysis reveals thirty novel putative PlcR-regulated genes in Bacillus cereus ATCC 14579 (type strain).
  • Kolstø, Anne-Brit; Helgason, Erlendur; Økstad, Ole Andreas Løchen; Johansen, Henning A.; Hegna, Ida Kristin & Caugant, Dominique A (2000). Bacillus Thuringiensis, Bacillus Cereus and Bacillus Anthracis: one species based on genetic evidence.
  • Økstad, Ole Andreas Løchen (2000). Sequence analysis of Bacillus cereus genome fragments - a comparative genome analysis.
  • Økstad, Ole Andreas Løchen & Kolstø, Anne-Brit (2000). High gene sequence conservation between Bacillus cereus and Bacillus anthracis.

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Published Nov. 3, 2010 3:46 PM - Last modified June 3, 2016 3:18 PM