P3-37 An Independent Laboratory Evaluation of a Salmonella spp Detection Kit

Wednesday, July 31, 2013
Exhibit Hall (Charlotte Convention Center)
Erin Crowley, Q Laboratories, Inc., Cincinnati, OH
Patrick Bird, Q Laboratories, Inc., Cincinnati, OH
Kiel Fisher, Q Laboratories, Inc., Cincinnati, OH
M. Joseph Benzinger, Q Laboratories, Inc., Cincinnati, OH
Megan Boyle, Q Laboratories, Inc., Cincinnati, OH
James Agin, Q Laboratories, Inc., Cincinnati, OH
David Goins, Q Laboratories, Inc., Cincinnati, OH
Marcia Armstrong, QIAGEN GmbH, Hilden, Germany
Corinna Kueppers, QIAGEN GmbH, Hilden, Germany
Sarah Fakih, QIAGEN GmbH, Hilden, Germany
Sandra Luley, QIAGEN GmbH, Hilden, Germany
Holger Engel, QIAGEN GmbH, Hilden, Germany
Introduction: The globalized food industry demands rapid, accurate, and easy-to-use pathogen detection systems. Increasingly, real-time PCR is relied upon to meet these demands. The mericon™Salmonella spp. method combines one of two straightforward sample preparation methods with real-time PCR detection using two kits.

Purpose: This internal evaluation was to conduct a comparison of the new method to the ISO 6579 reference method for the detection of Salmonella as part of the AOAC-RI™ validation process.

Methods: The method comparison analyzed a total of eight foods including raw ground beef (30% fat), chicken carcass rinses, creamy non-organic peanut butter, fresh spinach, pasteurized whole milk, instant nonfat dry milk, milk chocolate and shell eggs and pet food and environmental samples. Each matrix was inoculated with a different serotype of Salmonella at two levels (0.2-2 CFU/25 g and 2-5 CFU/25 g). For each sample, DNA was extracted by both the manual DNA and automated DNA extraction kits, analyzed by the RotorGene real-time PCR system and compared to the ISO 6579 reference method. Test kits were also evaluated for ruggedness, inclusivity and exclusivity.

Results: The method comparison demonstrated no significant differences in the number of positive samples detected between the mericon method and the ISO method for all matrices studied (POD statistical model).  All 103 inclusivity strains tested were positively detected.  All 31 non-target exclusivity strains tested were not detected. The ruggedness evaluation indicated that minor modifications did not affect the outcome of the method.

Significance: This new method is an efficient and reliable alternative to the traditional reference methods of detecting Salmonella in a variety of foods, feed and environmental samples.