Studies on the contamination of products produced by rendering plants.

Studies on the bacterial contamination in rendered product and the environment of five rendering plants were carried out. From a total of 180 samples examined, total bacterial and anaerobic spore counts were conducted on 135. Plants with melter systems produced a sterile product which was recontaminated before reaching the finished stage. Two plants with continuous rendering systems did not achieve sterilization of the product during the heating process. Spore forming organisms regularly survived heating in the continuous rendering system. Salmonellae were isolated from samples collected in four of the five plants under study. Pathogenic Clostridia, especially Cl. novyi, Cl. septicum and Cl. perfringens were present in samples from all plants. Other pathogens found were Staphylococci, Streptococci, Corynebacteria and Pasteurella.