| Popis: |
A study was conducted to determine the efficacy of media prescribed by the Food and Drug Administration as compared with other media reported in the literature for the isolation of Salmonella senftenberg, Salmonella thompson and Salmonella typhimurium from poultry feces, turkey roll and egg meat. The enrichment broths tested were: Gram Negative (Difco Laboratories), Rappaport’s Enrichment (Rappaport et al.. 1956), Selenite Cystine and Tetrathionate (Difco Laboratories). The plating media tested were: Brilliant Green Agar (Difco Laboratories), Brilliant Green-Neutral Red Lactose Agar (Slavin, 1943), Bismuth Sulfite Agar, Eosin Methylene Blue Agar, Hektoen Enteric Agar, MacConkey Agar, S S Agar and X L D Agar, all from Difco Laboratories. To nine ml. of each of the enrichment broths were added one ml. of test material slurry and 0.5 ml. of diluent containing the organism to be tested. There were 36 possible combinations of enrichment broths, species of Salmonella and test material. These tubes were incubated at 35°C. for 18 to 24 hours. Following incubation the tubes were used to streak the eight different plating media. The plates were incubated for 24 hours at 35° C. Typical colonies were inoculated into Triple Sugar Iron Agar slants. These inoculated slants were incubated at 35° C. for 24 hours. The presumptive isolates were tested biochemically and serologically for confirmation. Positive recoveries were made from 30.2% of the tubes inoculated with S. senftenberg. Tubes inoculated with S. thompson produced 23.9% recoveries while those inoculated with S. typhimurium yielded only 9.37% positive recoveries. Egg meat yielded the greatest percentage of recovery of test organisms (50%) while feces and turkey roll yielded only about seven percent. Of the four enrichment broths tested, Gram Negative, Rappaport’s and Selinite Cystine were superior to Tetrathionate yielding approximately 27.7% positive recoveries as compared with approximately five percent for Tetrathionate. Positive recoveries for the plating media were as follows: Salmonella-Shigella 41.6%; Eosin Methylene Blue and Hektoen Enteric, 22.2%; Brilliant Green and Brilliant Green Neutral Red Lactose, 19.4% and Bismuth Sulfite and X L D, 13.8%. |
