title: Tracking bacterial virulence: global modulators as indicators.
abstract: The genomes of Gram-negative bacteria encode paralogues and/or orthologues of global modulators. The nucleoid-associated H-NS and Hha proteins are an example: several enterobacteria such as Escherichia coli or Salmonella harbor H-NS, Hha and their corresponding paralogues, StpA and YdgT proteins, respectively. Remarkably, the genome of the pathogenic enteroaggregative E. coli strain 042 encodes, in addition to the hha and ydgT genes, two additional hha paralogues, hha2 and hha3. We show in this report that there exists a strong correlation between the presence of these paralogues and the virulence phenotype of several E. coli strains. hha2 and hha3 predominate in some groups of intestinal pathogenic E. coli strains (enteroaggregative and shiga toxin-producing isolates), as well as in the widely distributed extraintestinal ST131 isolates. Because of the relationship between the presence of hha2/hha3 and some virulence factors, we have been able to provide evidence for Hha2/Hha3 modulating the expression of the antigen 43 pathogenic determinants. We show that tracking global modulators or their paralogues/orthologues can be a new strategy to identify bacterial pathogenic clones and propose PCR amplification of hha2 and hha3 as a virulence indicator in environmental and clinical E. coli isolates.
authors.affiliation: Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda, Diagonal 643, 08028, Barcelona, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Prieto
authors.affiliation: Institut de Bioenginyeria de Catalunya (IBEC), Baldiri Reixach 15-21, 08028, Barcelona, Spain.
authors.forename: Imanol
authors.initials: I
authors.lastname: Urcola
authors.affiliation: Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela, 27002, Lugo, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Blanco
authors.affiliation: Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela, 27002, Lugo, Spain.
authors.forename: Ghizlane
authors.initials: G
authors.lastname: Dahbi
authors.affiliation: Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda, Diagonal 643, 08028, Barcelona, Spain.
authors.forename: Maite
authors.initials: M
authors.lastname: Muniesa
authors.affiliation: Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda, Diagonal 643, 08028, Barcelona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Quirós
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig University, Schubertstrasse 81, 35392 Giessen, Germany and German Center for Infection Research DZIF, Partner site Giessen-Marburg-Langen, Campus Giessen, Germany.
authors.forename: Linda
authors.initials: L
authors.lastname: Falgenhauer
authors.affiliation: Institute of Medical Microbiology, Justus-Liebig University, Schubertstrasse 81, 35392 Giessen, Germany and German Center for Infection Research DZIF, Partner site Giessen-Marburg-Langen, Campus Giessen, Germany.
authors.forename: Trinad
authors.initials: T
authors.lastname: Chakraborty
authors.affiliation: Institut de Bioenginyeria de Catalunya (IBEC), Baldiri Reixach 15-21, 08028, Barcelona, Spain.
authors.forename: Mário
authors.initials: M
authors.lastname: Hüttener
authors.affiliation: Departament de Microbiologia, Facultat de Biologia, Universitat de Barcelona, Avda, Diagonal 643, 08028, Barcelona, Spain.|Institut de Bioenginyeria de Catalunya (IBEC), Baldiri Reixach 15-21, 08028, Barcelona, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Juárez
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics / Q000378:metabolism; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D014774:Virulence
chemical_list: D018830:Adhesins, Escherichia coli; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C118376:antigen 43, E coli; C079209:hha protein, E coli