DNA damage was detected by the comet assay in HeLa cells exposed to <i>E. coli</i> for 3 h.

<p>DNA damage was not detected in HeLa cells infected with the <i>E. coli</i> strain IHE3034 Δ<i>clbP</i> harboring a defective <i>pks</i> island (A). Comet assay was positive in HeLa cells infected with the <i>E. coli</i> strain IHE3034 harboring <i>pks</i> island (B) or with <i>E. coli</i> devoid of known cyclomodulin-encoding genes (C).</p

Colonization of diverticulosis and CRC samples by <i>E. coli</i> phylogroups (A, B1, B2 and D).

<p>Colonization of diverticulosis and CRC samples by <i>E. coli</i> phylogroups (A, B1, B2 and D).</p

Adhesion ability of <i>E. coli</i> strains isolated from diverticulosis and CRC (proximal and distal) samples to Int-407 intestinal epithelial cells.

<p>A, adhesion ability according to the specimen origin and E. coli phylogroup. B, Adhesion ability of <i>E. coli</i> strains isolated from diverticulosis and CRC (proximal and distal) samples and belonging to A and D phylogroups according to their ability to produce or not a cyclomodulin/genotoxin. The results are expressed as number of adherent bacteria per cell after 3 h infection period. Data are means+/−SEM for at least 3 independent experiments.</p

Cytopathic effect induced by <i>E. coli</i> live bacteria or protein extracts on epithelial cells at three-day post-infection.

<p>For CNF and CDT, the cytopathic effect is only observable with bacterial lysates. In contrast, for colibactin and CIF, a contact between bacteria and host cells is required. Colibactin, CDT and CIF induced cytopathic effects as seen by enlarged nuclei and cell distension (megalocytosis), while CNF induced multinucleation and enlargement of HeLa cells.</p

Distribution of <i>E. coli</i> strains producing various cyclomodulins according to phylogroups and specimen origins.

<p>A, <i>E. coli</i> strains (n = 70) isolated from CRC samples (n = 38), and B, <i>E. coli</i> strains (n = 46) isolated from diverticulosis samples (n = 31).</p