Detection of Salmonella species in foodstuffs

Methods Mol Biol. 2008:429:33-43. doi: 10.1007/978-1-60327-040-3_3.

Abstract

Conventional methods to detect Salmonella spp. in foodstuffs may take up to 1 wk. Methods for pathogen detection are required. Real-time detection of Salmonella spp. will broaden our ability to screen large number of samples in a short time. This chapter describes a step-by-step procedure using an oligonucleotide probe that becomes fluorescent upon hybridization to the target DNA (Molecular Beacon; MB) in a real-time polymerase chain reaction (PCR) assay. The capability of the assay to detect Salmonella species from artificially inoculated fresh- and fresh-cut produce as well as ready-to-eat meats is demonstrated. The method uses internal positive and negative controls which enable researchers to detect false-negative PCR results. The procedure uses the buffered peptone water for the enrichment of Salmonella spp. and successfully detects the pathogen at low level of contamination (2-4 cells/25 g) in <24 h.

MeSH terms

  • Colony Count, Microbial
  • Food Contamination / analysis*
  • Food Microbiology*
  • Meat / microbiology*
  • Polymerase Chain Reaction / methods*
  • Salmonella / isolation & purification*
  • Vegetables / microbiology*