Uropathogenic Escherichia coli P and Type 1 Fimbriae Act in Synergy in a Living Host to Facilitate Renal Colonization Leading to Nephron Obstruction
Figure 5
Infection affects renal filtration.
Glomerular filtration in non-infected (I) and infected (II) tubules 4 h (A,B) and 8 h (C, D) after LT004 infusion is visualized 7, 20, and 80 s after iv bolus infusion of 10 kDa dextran (red). These data sets are representatives from a single animal, the experiments were performed on at least 3 separate occasions. The dynamic aspect of renal filtration and clearance can be seen in Videos S2 and S3, from which these frames originate. (A) Efficient filtration of the non-infected nephron (I) is visualized by the appearance of the bright red dextran in the tubule lumen (20 s), followed by a drop in intensity (80 s) indicating clearance. A less dramatic intensity change is seen in the infected nephron, indicating less filtration. Epithelial dextran uptake (arrow, 80 s) indicates epithelial dysfunction in infected tubule. Healthy epithelia in non-infected tubule exclude the dextran (arrowhead, 80 s). (B) Quantification of the mean intensity of dextran in tubule lumens over 80 s. Dotted red line corresponds to luminal intensity in the non-infected tubule (I), black line corresponds to the infected tubule (II). (C–D) The absence of filtrated dextran in the infected tubule (II) demonstrates compromised filtration at 8 h. Tissue shows accumulation of some dextran from previous bolus infusions. Scale bars = 30 µm. (E) Enlarged 50 µm inset from 5A 7 s showing dextran leaking into epithelial cells (arrowhead) from the basal side of the cells.