The incidence and level of contamination of British fresh sausages and ingredients with salmonellas.

A five-tube most probable number (MPN) method, with the pre-enrichment and enrichment stages, was used in a study of the incidence of salmonella contamination of British fresh sausages and the ingredients used in their manufacture. All samples were taken from a large factory in the course of routine production. There was an incidence of 65% contamination of pork (n = 20) and 55% (n = 20) in pork and beef sausages. The incidences of contamination of uncooked ingredients varied from 95% for mechanically recovered meat (n = 20) to 10% for another type of meat. Cooked and/or dried ingredients were rarely contaminated with these organisms, and when contamination occurred, coliforms were also important. The numbers of salmonellas isolated ranged from 7-40 for pork sausages, from 8-24 for beef and pork sausages and from 0.8-378 organisms/g for ingredients. The following salmonella serotypes were isolated (ranked in descending order or incidence): S. derby, S. dublin, S. newport, S. stanley. S. typhimurium, S. heidelberg, S. infantis and S. agona.