data of figure 1

Quantification of E. coli 536 in the feces in each mouse along the experimen

data of figure 5

The data used to produce the box plots of the figure 5 are presented in this tabl

data of figure 4

The results of flux cytometry are presented in this tabl

Non B2 grew faster than B2 in high pH high osmolarity.

<p>Boxplots of the doubling times (DT) in minutes of 12 B2 and 10 non-B2 representative strains of <i>E. coli</i> in LB, pH 8.5 with 350 mmol/L of sodium. We found a significant difference between B2 strains and non B2 strains using a Welch test (p = 0.001).</p

Impact of <i>nhaAR</i> operon on virulence.

<p>Lines represent the survival of OF1 mice after subcutaneous injection of 10⁸ cells of the following strains. In (A), (B) and (C) black solid lines, K-12 MG1655 and red solid lines, strain 536. In (A) orange, blue and green solid lines, mice injected with mutants 536Δ<i>nhaR</i>, 536Δ<i>nhaA</i> and 536Δ<i>nhaAR</i>, respectively. In B (C) dashed-dotted lines, complemented mutants 536Δ<i>nhaA</i> pGC<i>nhaAR</i> (536Δ<i>nhaAR</i> pGC<i>nhaAR</i>), dashed lines, complemented mutants 536Δ<i>nhaA</i> pGC<i>nhaA</i> (536Δ<i>nhaAR</i> pGC<i>nhaA</i>), solid lines, 536Δ<i>nhaA</i> (536Δ<i>nhaAR</i>) and dotted lines, complemented mutants 536Δ<i>nhaApGC</i> (536Δ<i>nhaAR</i> pGC).</p

Genomic organization of <i>nhaAR</i> region.

<p>(A) Genomic representation of <i>nhaAR</i> and other operons under NhaR regulation in K-12 <i>E.coli</i> strain from <a href="http://www.ecocyc.org" target="_blank">http://www.ecocyc.org</a>. All transcription or translation regulators are indicated. (B) GC percent along IAI39 <i>nhaAR</i> region (black line) and mean core genome GC percent (gray line) (C) Organization in various modules of <i>nhaAR</i> region. The modular organization of the region was defined using synteny breaks between 10 pathogenic and commensal <i>E. coli</i> and 2 clades strains from various phylogenetic groups including K-12 and H617 (two group A commensal strains), IAI1 and O26:H11 (two group B1 commensal strains), B367 (a group D commensal strain), 042 (an enteroaggregative group D, E2348/69 (an enteropathogenic group B2 strain), 536 (an extra-intestinal pathogen group B2 strain), O157:H7 Sakaï (an enterohemorrhagic group E strain). The two <i>Escherichia</i> clades (C) used were M863 (CI) and E1118 (CV). Five homologous modules have been defined, <i>nhaAR</i> operon being the third. Dark green: Fragmented or complete <i>hokC</i> toxin-antitoxin system coding genes; turquoise: Fragmented or conserved region associated with putative cerebroside sulfatase coding genes; blue: <i>nhaAR</i> region; pink: Fragmented or conserved region associated with putative adhesin/fimbrial like protein coding genes; yellow: Fragmented or conserved Type 3 secretion system coding genes. IS are also indicated.</p

Multiple gains and losses of modules around <i>nhaAR</i> operon.

<p>A parsimonious scenario of gains and losses of the 5 modules defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108738#pone-0108738-g001" target="_blank">figure 1</a> is presented along the phylogenetic tree of the strains. – indicates losses and + acquisitions (colors of modules as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108738#pone-0108738-g001" target="_blank">figure 1</a>).</p

Recombinant <i>nhaA</i> B2 strains have a lower virulence.

<p>Lines represent the mean survival of OF1 mice after subcutaneous injection of 10⁸ cells of the following strains: solid line: K-12 MG1655; dotted line: B2 strains lacking recombination in <i>nhaA</i> (<i>i.e</i> CFT073, 536, S88, RS218) and dashed line: strains showing evidence of recombination in <i>nhaA</i> region (<i>i.e</i> ED1a, E2348/65, SE15, B671, H001, TA103, TA435).</p