Evaluation of real-time PCR vs automated ELISA and a conventional culture method using a semi-solid medium for detection of Salmonella.
OBJECTIVE
Evaluation of iQ-Check PCR Salmonella for Salmonella detection in artificially and naturally contaminated food and environmental field samples.


RESULTS
Artificially contaminated samples (poultry meat and ground red meat) subjected to cold- and freeze-stress, and 120 naturally contaminated samples (swabs and meat) were tested for Salmonella using the diagnostic semi-solid Salmonella medium (DIASALM) method, the Vidas assay and the iQ-Check PCR assay after 24 h enrichment in buffered peptone water.


CONCLUSIONS
Both the iQ-Check PCR and the Vidas assay provide a rapid and user friendly screening method for detection of Salmonella. False negative samples were obtained for the inoculated samples using both the iQ-Check PCR assay and the Vidas method when Salmonella cells were severely stressed. In total 45 of 120 naturally contaminated field samples showed Salmonella positive using the DIASALM method. The agreement percentage with the DIASALM method was respectively 92% for the iQ-Check PCR and 95% for the Vidas method.


CONCLUSIONS
False-negative samples were obtained for the inoculated samples using both the iQ-Check PCR assay and the Vidas method when Salmonella cells were severely stressed, e.g. freezing at -18 degrees C for 7 days. Of the 120 naturally contaminated field samples 45 showed Salmonella positive using the DIASALM method. The agreement percentage with the DIASALM method was 92% for the iQ-Check PCR and 95% for the Vidas method respectively.
Uyttendaele
M
M
Laboratory of Food Microbiology and Food Preservation, Department of Food Science and Nutrition, Faculty of Agricultural and Applied Biological Sciences, University of Gent, Belgium. mieke.uyttendaele@ugent.be
Vanwildemeersch
K
K
Debevere
J
J
D001331:Automation; D003470:Culture Media / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D008460:Meat / Q000382:microbiology*; D009693:Nucleic Acid Hybridization / Q000379:methods; D016133:Polymerase Chain Reaction / Q000379:methods*; D012475:Salmonella / Q000302:isolation & purification*; D012680:Sensitivity and Specificity
D003470:Culture Media