FIG. 4.

Enteropathogenic responses to E. coli PMK5 and isogenic eae, tir, and stx1 mutants in the mid-ileum of ca. 28-day-old conventional calves. (A) Fluid accumulation. To correct for interanimal variation, the mean V/L ratio for each mutant strain was expressed as a percentage of the mean V/L ratio for the wild type in the same calf. The mean percentage plus SEM from three independent experiments is shown. (B) Neutrophil influx. The total ¹¹¹In activity in the contents and mucosa of test loops was corrected for loop length and expressed as a ratio to the activity in negative control loops. Neutrophil influx for the mutant strains was then calculated as a percentage of the influx for the wild type, and the mean of the three experiments plus SEM was derived.