Reference material for the evaluation of a standard method for the detection of salmonellas in foods and feeding stuffs

摘要

To evaluate a standard salmonella isolation method a reference material consisting of 0.2 g spray‐dried milk inoculated withSalmonella typhimuriumand contained in gelatin capsules was prepared. The organisms were distributed homogeneously between capsules, and their numbers were stable for 120 d when the capsules were stored in dry conditions at 4d̀C. Addition of these capsules with or without food samples to pre‐enrichment broth gave low and reproducible levels ofSalm. typhimuriumcontamination without altering the pre‐enrichment and without influencing the other bacterial flora present. As a result of an interlaboratory trial, the reference material indicated that the food and/or its competitive flora may have a negative influence on the detection of salmo