FIG. 2.

TOP52 progresses through an IBC pathogenic pathway. Histologic analysis of murine bladders after a 6-h infection with TOP52 (A) or UTI89 (B) revealed morphologically identical IBCs within superficial urothelial cells. Immunohistochemistry demonstrated that bacteria express type 1 pili within IBCs of both TOP52 (C) and UTI89 (D) infections. Staining was done with antibodies against type 1 pili (green) and the facet cell marker uroplakin III (red), and nuclei were visualized with Hoescht staining (blue). Urine samples from mice at 24 h postinfection with TOP52 (E) or UTI89 (F) contained long bacterial filaments. IBCs were quantified after visualization by LacZ staining and revealed that TOP52 forms significantly fewer IBCs than UTI89 at both 6 and 24 h postinoculation (G). Short bars represent geometric means, and significant P values, as calculated using the Mann-Whitney U test, are shown on the figure. Scale bar, 10 μm (A to F).