SYMPOSIUM ON METHODOLOGY FOR SALMONELLA IN FOOD.

The convenor called attention to the wideSalmonella cultures than brilliant green from spread distribution of the salmonella in man's both raw and pasteurized liquid eggs. The two environment. With the rapid development of plating media were equally effective for isolating food processing, the problem was discussed of Salmonella from the pasteurized glucose-free egg evaluating the Salmonella hazard in prepared powder. A comparison of three enrichment foods which are uncooked or inadequately heated broths, Selenite-F, tetrathionate, and Selenite-F to destroy Salmonella before serving. If illness containing 10 mg of cystine/liter, was made using follows the eating of such food nationally disthree egg albumens as the inocula. The results tributed and the same type of Salmonella is showed that the greatest number of positive culidentified in the food and in the patient, the tures was obtained from Selenite-F with added problem that arises involves action by the Federal cystine. Qualitative methods for the detection of Food and Drug officials. No bacteriological standSalmonella in pre-cooked frozen meals, yeast, and ards are available to enable the food processor egg albumen are described. to safeguard his product from Salmonella. Mildred M. Galton reported on a study of Ralph F. Hussong then stated that the numvarious techniques for the isolation of Salmonella ber of salmonella in egg albumen is determined from meat and meat products studied comat present by the Most Probable Number paratively; the methods developed were deMethod. The use of enrichment broths, selective scribed in detail. An excessive amount of meat in streaking agars and confiing tests in the MPN the tetrathionate broth inhibited its selective method leaves much to be desired from the enrichment. The optimum amount of inoculum standpoint of time, cost, and accuracy. Conseand the ratio of this to enrichment was deterquently, the possibility of using a direct plating mined. Of the various materials and methods technique in order to simplify the method of tried to emulsify fat adequately, the addition of determining numbers of the salmonella is being d-tergitol3 was the most effective. It was estabinvestigated in this laboratory. So far some 35 lished that 6 ml of a 10 per cent solution of dcommercial and experimental spray and pantergitol added to a 30-g pork sausage sample in dried samples of egg albumen have been ex100 ml of enrichment was superior to earlier amined for Salmonella by both direct plating on techniques. The heavy overgrowth of Pseudobismuth sulphite agar and by the usual routine monas and coliform organisms on plates of method involving enrichment broth. Different brilliant green agar inoculated from the enrichcounts obtained by both methods on samples ment was found to be effectively controlled by which contained a low number of Salmonella the addition of 16 mg of sodium sulfadiazine per were, in some cases, not statistically significant. 100 ml of medium without detected inhibition of However, on samples which contained high Salmonella. Salmonella were isolated from 51 numbers of Salmonella, the counts obtained by (23 per cent) of 217 samples of fresh pork sauthe direct plating method were, in most cases, sage and from 16 (12.5 per cent) of 127 samples 10 to 100 times higher than counts obtained by of smoked sausage. The technique described was the MPN method. used successfully with slight modification in the Anne F. Byrne reported work in collaboration examination of 159 samples of dehydrated dog with Morton M. Rayman and Morris D. Schneifoods. Of 98 samples of dog meal, 26 (26.5 per der for determining the MPN of Salmonella in cent) yielded Salmonella, but none was found in eggs. Bismuth sulfite agar yielded more positive 54 samples of pressed foods.