An evaluation of conventional culture, invA PCR, and the real-time PCR iQ-Check kit as detection tools for Salmonella in naturally contaminated premarket and retail turkey

J Food Prot. 2008 Feb;71(2):386-91. doi: 10.4315/0362-028x-71.2.386.

Abstract

This study was aimed at comparing the ability of conventional culture, the iQ-Check real-time PCR kit, and invA PCR to detect Salmonella in naturally contaminated premarket and retail turkey parts. Premarket (n = 120) turkey parts collected from a commercial turkey processing plant, and retail turkey parts (n = 138) were examined. Both PCR methods detected a significantly greater (P < 0.05) number of positive samples when compared with the conventional culture method for the premarket turkey parts. The indices of total agreement between the conventional culture method and the iQ-Check kit for the premarket and retail parts were 79.2% (95% CI: 70.8, 86) and 90.6% (95% CI: 84.4, 94.9), respectively. When the conventional culture method was compared with invA PCR for Salmonella detection in the premarket and retail parts, the indices of total agreement were 75.8% (95% CI: 67.2, 83.2) and 84.1% (95% CI: 76.9, 89.7), respectively. The rates of false positives (premarket: 31.9%, retail: 9.7%) and false negatives (premarket: 5.9%, retail: 9.7%) were determined between the culture method and the iQ-Check kit. When invA PCR was compared with the culture method, the rates of false positives (premarket: 37.7%, retail: 11.1%) and false negatives (premarket: 5.9%, retail: 18.3%) were obtained. The higher total agreement and the lower rates of both false positives and false negatives for the iQ-Check kit compared with invA PCR for both premarket and retail turkey parts corroborates the use of the iQ-Check kit as a screening tool for Salmonella in poultry meat.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bacterial Proteins
  • Colony Count, Microbial / methods*
  • Consumer Product Safety
  • Culture Media
  • DNA, Bacterial / analysis
  • Food Contamination / analysis*
  • Food Microbiology
  • Humans
  • Meat / microbiology*
  • Polymerase Chain Reaction / methods*
  • Reproducibility of Results
  • Salmonella / isolation & purification*
  • Salmonella Food Poisoning / prevention & control
  • Sensitivity and Specificity
  • Turkeys

Substances

  • Bacterial Proteins
  • Culture Media
  • DNA, Bacterial
  • invA protein, Bacteria