Repair and Recovery of Thermally Injured Cells of Yersinia enterocolitica in Milk

Abstract

One standard strain of the organism MTCC-861 and the two culture isolates VRW-22 and CRW-15 were exposed to batch pasteurization (62.8°C for 30 min) in brain heart infusion broth, skim milk, and whole milk. The trials were repeated three times. None of the isolates survived pasteurization treatment. However, the studies were further directed toward the repair and recovery of thermally injured cells, if any, in peptone sorbitol bile broth, skim milk, and whole milk. The results revealed that only a low number of test cultures were recovered in peptone sorbitol bile broth after 8 days of incubation at 10°C. On the other hand, the recovery was still slower in skim and whole milk, with a detection of the test isolates only on 10 days of incubation under similar conditions.