ZMYM2 and infection: Since fim and pap operon deletion mutants were not included in the infection assays, improved epithelial cell adhesion of UTI89ΔpapR in the infection assays could not be attributed with certainty to P-fimbriae but rather just to a mannose resistant fimbrial type, While the agglutination and adhesion assays provide hints as to the nature of surface fimbriae expressed at the population level, by fimbriae-specific immunolabelling and flow cytometry we were able to examine single cells to demonstrate a greater fraction of P-fimbriated cells in the PapR null mutant when compared to UTI89wt.