Rapid Detection of Salmonella in Pet Food: Design and Evaluation of Integrated Methods Based on Real-Time PCR Detection

• Published in: Journal of food protection Vol. 75; no. 2; pp. 347 - 352
• Main Authors: BALACHANDRAN, Priya, FRIBERG, Maria, PETRAUSKENE, Olga V, TEBBS, Robert S, CHARBONNEAU, Duane, VANLANDINGHAM, V, KOZAK, K, MANOLIS, Amanda, BREVNOV, Maxim, CROWLEY, Erin, BIRD, Patrick, GOINS, David, FURTADO, Manohar R
• Format: Journal Article
• Language: English
• Published: Des Moines, IA International Association for Food Protection 01.02.2012; Elsevier Limited
• Subjects: Acids; Animal Feed - microbiology; Animals; Automation; Biological and medical sciences; Centrifugation; Colony Count, Microbial - methods; Consumer Product Safety; DNA, Bacterial - analysis; Experiments; Food Analysis - instrumentation; Food Analysis - methods; Food contamination & poisoning; Food Contamination - analysis; Food industries; Food matrix; Food Microbiology; Food safety; Fundamental and applied biological sciences. Psychology; General aspects; Methods; Methods of analysis, processing and quality control, regulation, standards; Nucleic acids; Pathogens; Pet food; Process controls; Public health; Raw materials; Real time; Real-Time Polymerase Chain Reaction; Risk reduction; Salmonella; Salmonella - isolation & purification; Time Factors; United States > US; Design; Polymerase chain reaction; Evaluation; Salmonella; Analysis method; Pet food; Bacteria; Control method; Molecular biology; Detection; Real time; Enterobacteriaceae
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X.JFP-11-210

Reducing the risk of Salmonella contamination in pet food is critical for both companion animals and humans, and its importance is reflected by the substantial increase in the demand for pathogen testing. Accurate and rapid detection of foodborne pathogens improves food safety, protects the public health, and benefits food producers by assuring product quality while facilitating product release in a timely manner. Traditional culture-based methods for Salmonella screening are laborious and can take 5 to 7 days to obtain definitive results. In this study, we developed two methods for the detection of low levels of Salmonella in pet food using real-time PCR: (i) detection of Salmonella in 25 g of dried pet food in less than 14 h with an automated magnetic bead-based nucleic acid extraction method and (ii) detection of Salmonella in 375 g of composite dry pet food matrix in less than 24 h with a manual centrifugation-based nucleic acid preparation method. Both methods included a preclarification step using a novel protocol that removes food matrix-associated debris and PCR inhibitors and improves the sensitivity of detection. Validation studies revealed no significant differences between the two real-time PCR methods and the standard U.S. Food and Drug Administration Bacteriological Analytical Manual (chapter 5) culture confirmation method.