STUDY ON THE EXPERIMENTAL TYPHOID

Abstract

In the previous paper it was reported that immunization of mice with living attenuated S. enteritidis strain SER was followed by strong active immunity to challenge infection with virulent strain 116-54. And one hundred percent of mice survived infection with 100 fold 10-7 mg (usual challenge dose) of virulent strain 116-54. The present investigation is an attempt to elucidate the relation between S. enteritidis and the abdominal monocytes of the mice. Monocytes were obtained from the abdominal cavity of normal and immune mice which had been given an intraperitoneal injection of glycogen solution as hemotactic agent four to five days prior to the collection. Cells were washed twice by centrifugation and then resuspended in Hanks's solution.The attenuated strain SER of S. enteritidis was used for living bacterial vaccine and chrome-alum vaccine for killed bacterial vaccine.The results were as follow : 1) The phagocytic activity of monocytes derived from mice immunized with killed bacterial vaccine was most active. And the activity of monocytes derived from normal mice was greater than that of monocytes derived from the mice immunized with living bacterial vaccine.2) There was on difference in the number of bacteria ingested in the monocytes derived from normal or immune mice.3) The monocytes derived from the mice immunized with living bacterial vaccine inhibited the intracellular multiplication of bacteria without regard to the presence of antibody.