FIG 8.

The urine small-molecule fraction supports robust UPEC filamentation. Phase-contrast microscopy and flow cytometry of UTI89/pGI5, harvested from the flow chamber infection model after day 2, with exposure to whole human urine (red) or small molecule human urine (<3000-Da fraction, blue), were performed. Scale bars, 5 μm. Flow cytometry showed very similar curves for both urine types, a left-hand peak with a large right-hand shoulder indicating a mixed population of short and filamentous bacteria; 12.2% of bacteria for whole urine and 12.7% of small molecule urine were filamentous.