STUDIES ON EXPERIMENTAL TYPHOID

COMPRATIVE STUDY ON THE LINING AND KILLED VACCINES IN THE PREVENTION OF INFECTION OF MICE WITH S.ENTERITIDIS

Abstract

1) Mice were challenged with virulent S.enteritidis 2 weeks after receiving chrome-alum vaccine. Sixthe percent survival occured when vaccine and challenge dose were administered intraperitoneally. However, mice were not so resistant to intravenous challenge when vaccine was administered intraperitoneally, suggesting some of the immunity observed might be owing to the local resistance in abdominal cavity.
2) Immunization of mice with attenuated S.enteritidis strain SER was followed by strong active immunity to challenge infection with virulent strain 116-54, One hundred percent of mice survived infection with 100 fold 10-7 mg of virulent strain 116-54. And the titer of O-H agglutinin following administration of chrome-alum vaccine was greater than that of mice immunized with attenuated living vaccine.
3) The monocytes derived from mice immunized with living vaccine inhibited the intracellular multiplication of bacteria without regard to the presence of antibody.