The survival of the Calmette-Guérin strain of tubercle bacillus (B.C.G.) in the blood and mamma of goats

Abstract

Intravenously injected into a goat in a single dose of 50·0 mg. b.c.g. caused the death of the animal from pneumonia in 9 days and was demonstrated in the blood until the day of death, though in progressively diminishing numbers.Intravenously injected into a goat on successive occasions, the dose on each being 10·0 mg., b.c.g. was filtered from the blood by the tissues within 3–5 days. There was little or no evidence that b.c.g. disappeared from the blood more quickly after previous injection of that micro-organism. b.c.g. was not excreted into the milk cisterns of this goat or, if excreted, the bacilli did not long survive.Intramammarily injected b.c.g. produced inflammatory reactions in the mamma with formation of caseo-pus and ultimate destruction of the gland as a secretory organ. The micro-organisms, however, did not remain alive for any lengthy period in the mamma and in the two instances reported were not viable after about 15 weeks.