Stabilization of Salmonella-specific dialyzable leukocyte extracts

Abstract Activity of Salmonella -specific dialyzable leukocyte extracts (DLE) prepared from mesenteric lymphatic nodes of calves and stabilized with bovine albumin was studied in this work. The effect of ambient temperature and storage period on the activity of DLE was evaluated. Testing for DLE activity by means of capillary leukocyte migration inhibition (LMI) assay showed that DLE stabilized with albumin retained 60% of its activity for 12 months of storage at 4°C. This level of activity was retained in the native DLE (without albumin) kept at −20°C. DLE stabilized with albumin and stored for 12 months at 4°C inhibited the penetration of salmonellae into the liver and spleen, and their colonization in the gastrointestinal tract was significantly reduced.