FIG. 3.

Secretory response and PMN influx elicited by serovar Typhimurium strains in bovine intestinal loops. Approximately 1.5 × 10⁹ CFU of the wild-type strain SL3201 (WT), SL3201 flhD::Tn10(D-) or SL3201 fljB::MudJ fliC::Tn10 (B-C-) was injected into each loop and left for 12 h before analysis. LB broth (LB) was also used as a negative control. The secretory response is shown as volume per length of loop. The PMN influx is a ratio of the PMN radioactivity within the infected loops to the PMN radioactivity within the control loops. Each mean is calculated from either nine loops in three calves (secretory response) or six loops in two of the three calves (PMN influx) and is presented with the SE.