Figure 4.

Histology of Map infection sites in naïve and vaccinated calves. Panel (a) shows lesion score summary; late stage lesions scored significantly higher in vaccinates compared with naïve calves (*P = 0.0449). Late stage Map infection site lesions in naïve calves were characterized by diffuse granulomatous inflammation (see Figure 1b) while Map infection sites in previously vaccinated calves (panel b) scored higher because of increased fibrous tissue (arrow) and prominent large multinucleated Langhans-type giant cells (arrow heads). Bar = 100 μm.