Oxygen concentration modulates colibactin production.

Up to 25% of the strains isolated from the feces of healthy humans harbor the genomic island encoding the synthesis of colibactin, a genotoxic metabolite. Evidence is accumulating for an etiologic role of colibactin in colorectal cancer. Little is known about the conditions of expression of colibactin in the gut.

A novel toxic effect of foodborne trichothecenes: The exacerbation of genotoxicity.

Trichothecenes (TCT) are very common mycotoxins. While the effects of DON, the most prevalent TCT, have been extensively studied, less is known about the effect of other trichothecenes. DON has ribotoxic, pro-inflammatory, and cytotoxic potential and induces multiple toxic effects in humans and animals.

Outer membrane vesicles produced by pathogenic strains of block autophagic flux and exacerbate inflammasome activation.

strains are responsible for a majority of human extra-intestinal infections, resulting in huge direct medical and social costs. We had previously shown that HlyF encoded by a large virulence plasmid harbored by pathogenic is not a hemolysin but a cytoplasmic enzyme leading to the overproduction of outer membrane vesicles (OMVs). Here, we showed that these specific OMVs inhibit the macroautophagic/autophagic flux by impairing the autophagosome-lysosome fusion, thus preventing the formation of acidic autolysosomes and autophagosome clearance.

The Bacterial Stress-Responsive Hsp90 Chaperone (HtpG) Is Required for the Production of the Genotoxin Colibactin and the Siderophore Yersiniabactin in Escherichia coli.

The genotoxin colibactin, synthesized by Escherichia coli, is a secondary metabolite belonging to the chemical family of hybrid polyketide/nonribosomal peptide compounds. It is produced by a complex biosynthetic assembly line encoded by the pks pathogenicity island. The presence of this large cluster of genes in the E.