Nucleotide comparison of the putative virulence regions of pAPEC-O1-ColBM and pAPEC-O2-ColV using the Artemis comparison tool. Same-strand DNA homology is shaded red, while inverse homology is shaded pink. Genes are color coded as follows: maroon, etsABC; light orange, sitABCD; dark orange, aerobactin operon; purple, salmochelin operon; green, ColV operon; aqua green, eitABCD; pink, putative autotransporter/adhesin; blue, tsh; red, iss; yellow, mobile elements; tan and gray, genes of unknown function.