Comparative studies on the isolation of salmonella from minced meat.

Comparative studies carried out in four laboratories revealed that in the examination of frozen or fresh minced meat samples tryptone soya broth and glucose mineral salts medium used for pre-enrichment gave the same results as buffered peptone water. The three tetrathionate media (Cardiff formula, Difco and Oxoid) used for enrichment after pre-enrichment, yielded approximately the same number of positive samples and about the same number of frozen and cooled samples was found positive when data of all four laboratories were considered. Between laboratories a considerable variation in results was found. This indicates the necessity to conduct comparative trials in more than one laboratory to validate the use of a specific method for regulatory purposes.