Lung of rabbit infected with S. aureus: (a & b) showing an interstitial inflammatory reaction, hemorrhages, and focal peribranchial leukocytic infiltrations. (c) lung treated with an antibiotic, showing mild focal peribranchial aggregations along with mild interstitial pneumonia. (d) lung treated with antibiotic+ probiotic. showing mild thickening of interstitial tissue and mild congestion. H&E. X 100.