Ulrich Dobrindt

Publications (117) View all

• Article: Phylogenetic Group - Associated Differences in Regulation of the Common Colonization Factor Mat Fimbria in Escherichia coli.

  Timo A Lehti, Philippe Bauchart, Maini Kukkonen, Ulrich Dobrindt, Timo K Korhonen, Benita Westerlund-Wikström
  [show abstract] [hide abstract]
  ABSTRACT: Heterogeneity of cell population is a key component behind the evolutionary success of Escherichia coli. The heterogeneity supports species adaptation and mainly results from lateral gene transfer. Adaptation may also involve genomic alterations that affect regulation of conserved genes. Here we analyzed regulation of the mat (or ecp) genes that encode a conserved fimbrial adhesin of E. coli. We found that the differential and temperature-sensitive expression control of the mat operon is dependent on mat promoter polymorphism and closely linked to phylogenetic grouping of E. coli. In the mat promoter lineage favoring fimbriae expression, the mat operon-encoded regulator MatA forms a positive feedback loop that overcomes the repression by H-NS and stabilizes the fimbrillin mRNA under low growth temperature, acidic pH, or elevated levels of acetate. The study exemplifies phylogenetic group-associated expression of a highly common surface organelle in E. coli.
  Molecular Microbiology 01/2013; · 5.01 Impact Factor
• Article: E. coli as an All-Rounder: The Thin Line Between Commensalism and Pathogenicity.

  Andreas Leimbach, Jörg Hacker, Ulrich Dobrindt
  [show abstract] [hide abstract]
  ABSTRACT: Escherichia coli is a paradigm for a versatile bacterial species which comprises harmless commensal as well as different pathogenic variants with the ability to either cause intestinal or extraintestinal diseases in humans and many animal hosts. Because of this broad spectrum of lifestyles and phenotypes, E. coli is a well-suited model organism to study bacterial evolution and adaptation to different growth conditions and niches. The geno- and phenotypic diversity, however, also hampers risk assessment and strain typing. A marked genome plasticity is the key to the great variability seen in this species. Acquisition of genetic information by horizontal gene transfer, gene loss as well as other genomic modifications, like DNA rearrangements and point mutations, can constantly alter the genome content and thus the fitness and competitiveness of individual variants in certain niches. Specific gene subsets and traits have been correlated with an increased potential of E. coli strains to cause intestinal or extraintestinal disease. Intestinal pathogenic E. coli strains can be reliably discriminated from non-pathogenic, commensal, or from extraintestinal E. coli pathogens based on genome content and phenotypic traits. An unambiguous distinction of extraintestinal pathogenic E. coli and commensals is, nevertheless, not so easy, as strains with the ability to cause extraintestinal infection are facultative pathogens and belong to the normal flora of many healthy individuals. Here, we compare insights into phylogeny, geno-, and phenotypic traits of commensal and pathogenic E. coli. We demonstrate that the borderline between extraintestinal virulence and intestinal fitness can be blurred as improved adaptability and competitiveness may promote intestinal colonization as well as extraintestinal infection by E. coli.
  Current topics in microbiology and immunology 01/2013; · 4.93 Impact Factor
• Source

  Available from: Maïwenn Olier

  Dataset: Supplementary data

  Maïwenn Olier, Ingrid Marcq, Christel Salvador-Cartier, Thomas Secher, Ulrich Dobrindt, Michèle Boury, Valérie Bacquié, Marie Pénary, Eric Gaultier, Jean-Philippe Nougayrède, Jean Fioramonti, Eric Oswald
• Source

  Available from: Maïwenn Olier

  Article: Genotoxicity of Escherichia coli Nissle 1917 strain cannot be dissociated from its probiotic activity.

  Maïwenn Olier, Ingrid Marcq, Christel Salvador-Cartier, Thomas Secher, Ulrich Dobrindt, Michèle Boury, Valérie Bacquié, Marie Pénary, Eric Gaultier, Jean-Philippe Nougayrède, Jean Fioramonti, Eric Oswald
  [show abstract] [hide abstract]
  ABSTRACT: Oral administration of the probiotic bacterium Escherichia coli Nissle 1917 improves chronic inflammatory bowel diseases, but the molecular basis for this therapeutic efficacy is unknown. E. coli Nissle 1917 harbors a cluster of genes coding for the biosynthesis of hybrid nonribosomal peptide-polyketide(s). This biosynthetic pathway confers the ability for bacteria to induce DNA double strand breaks in eukaryotic cells. Here we reveal that inactivation of the clbA gene within this genomic island abrogated the ability for the strain to induce DNA damage and chromosomal abnormalities in non-transformed cultured rat intestinal epithelial cells but is required for the probiotic activity of E. coli Nissle 1917. Thus, evaluation of colitis severity induced in rodent fed with E. coli Nissle 1917 or an isogenic non-genotoxic mutant demonstrated the need for a functional biosynthetic pathway both in the amelioration of the disease and in the modulation of cytokine expression. Feeding rodents with a complemented strain for which genotoxicity was restored confirmed that this biosynthetic pathway contributes to the health benefits of the probiotic by modulating its immunomodulatory properties. Our data provide additional evidence for the benefit of this currently used probiotic in colitis but remind us that an efficient probiotic may also have side effects as any other medication.
  Gut Microbes 11/2012; 3(6).
• Source

  Available from: Ulrich Dobrindt

  Dataset: High-throughput microarray technology in diagnostics of enterobacteria based on genome-wide probe selection and regression analysis Friedrich et al 2010

  Torben Friedrich, Sven Rahmann, Wilfried Weigel, Wolfgang Rabsch, Angelika Fruth, Eliora Ron, Florian Gunzer, Thomas Dandekar, Jörg Hacker, Tobias Müller, Ulrich Dobrindt