FIG. 3.

TOP52 ΔfimK has higher titers in organs and forms more IBCs in the murine cystitis model than the wild type. (A) The fim operons of E. coli and K. pneumoniae, which encode type 1 pili, have similar compositions and organizations, but the K. pneumoniae fim operon contains an extra gene of unknown function, fimK. (B) TOP52 ΔfimK had higher 6-h titers in the bladder than the wild type, and this phenotype was complemented with pfimK. (C) TOP52 ΔfimK also had consistently higher titers in the kidney at 6 h than the wild type, and this difference could be complemented back to wild-type levels. (D) Enumeration of IBCs at 6 h postinfection revealed that TOP52 ΔfimK forms more IBCs than TOP52. Titer and IBC data are combined from three independent experiments. Short bars represent geometric means of each group, and dotted lines represent limits of detection. Significant P values, as calculated using the Mann-Whitney U test, are shown in the figure.