Modeling the long-term kinetics of Salmonella survival on dry pet food

Elisabetta Lambertini; Abhinav Mishra; Miao Guo; Huilin Cao; Robert L Buchanan; Abani K Pradhan

doi:10.1016/j.fm.2016.02.003

Modeling the long-term kinetics of Salmonella survival on dry pet food

Food Microbiol. 2016 Sep:58:1-6. doi: 10.1016/j.fm.2016.02.003. Epub 2016 Feb 9.

Authors

Elisabetta Lambertini¹, Abhinav Mishra², Miao Guo², Huilin Cao², Robert L Buchanan¹, Abani K Pradhan³

Affiliations

¹ 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.
² Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA.
³ 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.

PMID: 27217351
DOI: 10.1016/j.fm.2016.02.003

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.

Keywords: Feed; Low water activity; Non-linear; Salmonella; Storage; Weibull.

MeSH terms

Animal Feed / microbiology*
Animals
Colony Count, Microbial / veterinary
Dogs
Food Contamination
Food Microbiology*
Food Storage
Kinetics
Microbial Viability
Models, Biological*
Risk Assessment / methods
Salmonella enterica / classification
Salmonella enterica / physiology*
Temperature
Time Factors
Water / physiology*

Substances

Water