FIG. 2.
Attenuation of MGA_1107 mutant of R strain in chickens. (A) Histopathological lesion scores in tracheas of chickens infected with Hayflick's medium (Medium), mutant (MGA_1107) organism, and virulent organism (Rlow). Horizontal bars indicate 25th percentile (bottom), median, and 75th percentile (top). Lowercase letters indicate statistically similar groups. (B) Tracheal mucosal thickness. Bar and letters are as described for panel A. (C) Microbiological recovery from tracheas of chickens. Dots indicate titers of samples recovered from individual birds.