''M. haemolytica'' is beta-haemolytic on blood agar and grows weakly on MacConkey agar. It is odourless. All are ''Mannheimia'' A biotypes and the strains often produce a cytotoxin, known as leukotoxin, which kills leukocytes of ruminants. Leukotoxin is a member of the RTX group toxins, and is probably largely responsible for the pathogenicity of the bacteria in septicaemia and pneumonia. | ''M. haemolytica'' is beta-haemolytic on blood agar and grows weakly on MacConkey agar. It is odourless. All are ''Mannheimia'' A biotypes and the strains often produce a cytotoxin, known as leukotoxin, which kills leukocytes of ruminants. Leukotoxin is a member of the RTX group toxins, and is probably largely responsible for the pathogenicity of the bacteria in septicaemia and pneumonia. |