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

Abstract

AbstractSalmonella 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.