Submitted to: Journal of Food Safety
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/23/2019
Publication Date: 3/15/2020
Citation: Cox Jr, N.A., Berrang, M.E., House, S.L., Hinton Jr, A., Line, J.E., Wiggins, L.T. 2020. Detection of multiple naturally occurring Salmonella serotypes from commercial broiler carcasses with conventional methods. Journal of Food Safety. 40:e12761. https://doi.org/10.1111/jfs.12761.
Interpretive Summary: With dozens of liquid and plating media to select from for running Salmonella analyses from broiler carcasses, this study looks at the variability when just a couple of each are used. The enrichment and plating media combinations along with the number of colonies selected influences the serotypes recovered and demonstrates the bias that may occur during cultivation of Salmonella even in a very limited study such as this. Also many variables were not addressed in this study such as multiple rinsing of carcasses, carcass incubated along with preenrichment broth, neck skin versus carcass rinse and stressed versus non stressed Salmonella, just to name a few. Therefore caution should be used when assigning varying levels of importance to the presence of individual serotypes on raw poultry.
Technical Abstract: Many laboratories sampling foods for Salmonella are interested only in presence or absence of Salmonella, so only one colony may be selected. The objectives of this study were to use two selective enrichment broths and two selective agar plating media for Salmonella recovery from naturally contaminated broiler carcass rinsates and evaluate these media combinations on Salmonella serotypes recovered from each carcass. Broiler carcasses (n=52) from a commercial processing plant prior to chilling were rinsed with buffered peptone water and after incubation subcultured to Gram Negative, Tetrathionate, and Rappaport Vasilliadis broths which were streaked onto plates of Brilliant Green Sulfa and Xylose-Lysine-Tergitol-4 agar. On 11/49 positive carcasses, both plating media yielded the same serotypes; for the other 38 positive samples different serotypes were found on the different plating media. Enrichment and plating media combinations influence the serotypes recovered and demonstrates bias even in a limited study such as this.