Efficiency of Salmonella isolation from meat-and-bone meal of one 300-g sample versus ten 30-g samples.

Twenty-five meat-and-bone meal samples were analyzed for salmonellae, comparing a single 300-g to ten 30-g samples. Seventeen were positive using the larger sample; eighteen were positive with the smaller. The 300-g sample showed a significantly higher (P < 0.01) percentage of confirmed salmonellae at 2 days of incubation than at 1 day. The ten 30-g samples did not show changes at 2 days. At 2 days, the 30-g samples showed significantly fewer confirmed salmonellae than the 300-g sample; however, there was no difference at 1 day. Of 1,417 presumptive colonies picked, 1,215 (85.7%) were lysine decarboxylase-positive and 1,152 (81.3%) were agglutinated by one of the somatic antisera. There were no significant differences in diversity or total numbers of different somatic groups between the large and small samples.