Immunoprophylactic properties of Propionibacterium avidum KP-40 in newborn calves

The immunoprophylactic properties of Propionibacterium avidum KP-40, a potent stymulator of the macrophage-monocyte system and inducer of endogenous interferon, were tested in newborn calves. A single subcutaneous injection of the immunomodulator was administered either immediately after delivery or to 4-week-old animals. During physiological maturation of the immune system and the disappearance of passive resistance transmitted by colostrum, a gradual reduction of serum γ-globulins and increase in conglutinin occurred in the 2nd month of life in untreated calves. Administration of Propionibacterium avidum caused a significant rise of both γ-globulins and conglutinin. This was accompanied by increased lymphocytosis and a higher number of E-rosetting (T) lymphocytes. It is concluded that administration of Propionibacterium avidum increases the natural resistance of newborn calves and offers an effective prophylaxis against development of spontaneous infections.