Brucella Abortus in Milk and Dairy Products

Abstract

Cream from milk from 378 cows injected into guinea pigs showed that 23 cows were eliminating Br. abortus in their milk. Two bovine strains of Br. abortus, artificially inoculated into cream and stored at 8[degree] C, remained viable for 8 days. Two other strains, 1 bovine and 1 human, more pathogenic for guinea pigs than the above, infected guinea pigs for 10 days after inoculation into cream. Two strains of Br. abortus artificially inoculated into butter and stored at 8[degree] remained viable and infected guinea pigs for 81 and 32 days, respectively. A bovine strain and the culture isolated from the blood of man were viable 142 days after inoculation into butter, but not after 192 days. Guinea pigs injected with 17 samples of market creamery butter showed no evidence of Br. abortus infection at necropsy. Guinea pigs injected with 82 samples of cheeses, mostly imported varieties, failed to show evidence of Br. abortus or Br. rnelitensis infection.