Maternally Transmitted Immunity to Bacillus Sordellii.

Abstract

During our efforts 1 to produce antitoxic and agglutinating serums against Bacillus sordellii (C. oedematoides), one of our immunized rabbits accidentally became pregnant and gave birth to 10 young of which she succeeded in raising 4. When these were weaned it occurred to me to test their immunity toward the organism which had been used in the immunization of their mother.

Since details of immunization of the mother preceding and during gestation, as well as during lactation may be of some significance for the interpretation of the immunity conferred upon her young, they are here noted in tabular form.

Female rabbit No. 261 was immunized against B. sordellii 1302 as shown in Table I.

The following schedule is submitted in detail as an example of successful immunization against whole cultures of B. sordellii. We have never succeeded in immunizing rabbits against whole cultures by the intravenous route and sacrificed many in attempting to do so. Even animals as completely immunized as this rabbit was at the end, have succumbed to small doses of whole cultures administered into the vein.

It is clear that this rabbit possessed a well established antitoxic immunity before or about the time gestation started. This is shown by the fact that in spite of the relatively large doses of toxin received, she continued to gain weight and showed no alarming symptoms, only a moderate degree of localized oedema after each subcutaneous inoculation. Serum separated from the blood drawn after the first week of gestation also possessed definite protective power for guinea pigs inoculated simultaneously with filtered cultures of B. sordellii and C. oedematoides. Furthermore, repeated inoculations of this pregnant rabbit did not cause her to abort, as so often happens, and she continued to gain weight both during gestation and after parturition in spite of constantly increasing doses of first toxin, and later, whole cultures.