Comparison of selective enrichment and plating media for Salmonella isolation from broiler carcasses

• Published in: Journal of food safety Vol. 41; no. 6
• Main Authors: Obe, Tomi, Berrang, Mark E., Cox, Nelson A., House, Sandra L., Shariat, Nikki W.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.12.2021; Blackwell Publishers Inc
• Subjects: Broths; Carcasses; Enrichment media; Food safety; Isolation media; Lysine; Peptones; Plating; Recovery; Salmonella; Selective media; Tetrathionate
• ISSN: 0149-6085; 1745-4565
• DOI: 10.1111/jfs.12928

Salmonella detection and isolation rely on different selective enrichment media, which can influence which serovars are detected. The objective of this study was to compare Salmonella recovery from broiler carcass rinses using three different selective enrichment protocols and three differential plating agars. Eight prechill broiler carcasses were collected at a commercial slaughter facility. Each carcass was subjected to whole carcass rinse procedure in buffered peptone water (BPW). An aliquot of the rinse and whole carcasses in the remaining rinse were incubated as a pre‐enrichment before subculturing in selective enrichment broths (Rappaport Vassiliadis [RV], Tetrathionate Hajna [TT], and TT to RV in series [TT‐to‐RV]). Enriched samples were streaked on the three differential agars (Hektoen Enteric [HE], Brilliant Green Sulfa [BGS], and Xylose‐Lysine‐Tergitol‐4 [XLT‐4]). Salmonella was isolated from all eight carcasses. Considering all sample preparations as independent subsamples, Salmonella was detected in 88% (128/144) of subsamples with a 100% recovery from the TT‐to‐RV enrichment, and 92 and 71% from RV and TT broths, individually. A high concordance in recovery on BGS versus XLT‐4 agar plates was observed compared to HE versus BGS and HE versus XLT‐4 plates. These data suggest that choice of pre‐enrichment method, selective enrichment medium, and differential agar can influence the recovery of Salmonella from poultry samples. Salmonella isolation takes multiple days to complete and involves the use of different types of selective enrichment media and differential selective agars. This work compared the isolation and serovar identities of Salmonella recovered from broiler carcasses using different media.