ABSTRACT Colibactins are hybrid polyketide-nonribosomal peptides produced by Escherichia coli. Klebsiella pneumoniae. and other Enterobacteriaceae harboring the pks genomic island. These genotoxic metabolites are produced by pks-encoded peptide-polyketide synthases as inactive prodrugs called precolibactins. https://www.roneverhart.com/Ray-Ban-RB3519-59mm/