Occurrence of Multiple Salmonella Types in Spray-Dried Whole-Egg Powder

Abstract A VARIETY of Salmonella types have been isolated from spray-dried whole egg powder (Solowey et al., 1947). The frequency distribution of these types was based largely on the serological identification of only 1 presumptive positive colony isolate per sample. However, when occasionally 2 colony isolates per sample were identified, it was observed that in some cases 2 Salmonella types were present. In order to observe further the number of types present, serological follow-ups were made on 2 to 30 colony isolates from each of 171 samples. This paper summarizes the findings. At first, a random selection of egg powder samples was made for this study. However, in order to avoid too many Salmonella-negative samples, selection was later made from dehydration plants which had previously contributed a high percentage of Salmonella-positive samples. These samples ‡ represented U. S. Department of Agriculture lots of egg powder produced in 46 plants located in 17 . . .