title: Modeling the long-term kinetics of Salmonella survival on dry pet food.
abstract: Due to multiple outbreaks and large-scale product recalls, Salmonella has emerged as a priority pathogen in dry pet food and treats. However, little data are available to quantify risks posed by these classes of products to both pets and their owners. Specifically, the kinetics of Salmonella survival on complex pet food matrices are not available. This study measured the long-term kinetics of Salmonella survival on a dry pet food under storage conditions commonly encountered during production, retail, and in households (aw < 0.60, 23 °C). A Salmonella enterica cocktail of 12 strains isolated from dry pet foods and treats was used to inoculate commercial dry dog food. Salmonella was enumerated on non-selective (BHI) and selective (XLD and BS) media. Results at 570 days indicated an initial relatively rapid decline (up to 54 days), followed by a much slower extended decline phase. The Weibull model provided a satisfactory fit for time series of Log-transformed Salmonella counts from all three media (δ: mean 4.65 day/Log (CFU/g); p: mean 0.364 on BHI). This study provides a survival model that can be applied in quantitative risk assessment models.
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA; Center for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Lambertini
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA.
authors.forename: Abhinav
authors.initials: A
authors.lastname: Mishra
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA.
authors.forename: Miao
authors.initials: M
authors.lastname: Guo
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA.
authors.forename: Huilin
authors.initials: H
authors.lastname: Cao
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA; Center for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Buchanan
authors.affiliation: Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA; Center for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA. Electronic address: akp@umd.edu.
authors.forename: Abani K
authors.initials: AK
authors.lastname: Pradhan
mesh_terms: D000821:Animal Feed / Q000382:microbiology*; D000818:Animals; D015169:Colony Count, Microbial / Q000662:veterinary; D004285:Dogs; D005506:Food Contamination; D005516:Food Microbiology; D061353:Food Storage; D007700:Kinetics; D050296:Microbial Viability; D008954:Models, Biological; D018570:Risk Assessment / Q000379:methods; D019779:Salmonella enterica / Q000145:classification / Q000502:physiology*; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000502:physiology*
chemical_list: D014867:Water
keywords: Feed; Low water activity; Non-linear; Salmonella; Storage; Weibull