title: Growth of Shiga toxin-producing Escherichia coli (STEC) and impacts of chilling and post-inoculation storage on STEC attachment to beef surfaces.
abstract: Concern has been expressed surrounding the utility of studies describing the efficacy of antimicrobial interventions targeting the Shiga toxin-producing Escherichia coli (STEC) that inoculate chilled versus non-chilled beef carcasses. The objectives of this study were to evaluate the effects of chilling (non-chilled, chilled to surface temperature of ≤5 °C) on STEC attachment to brisket surfaces, and the effects of post-inoculation storage on STEC recovery. Paired briskets from split carcasses were separated; one brisket from each pair was kept non-chilled, while the other was chilled to a surface temperature of ≤5 °C prior to inoculation. Briskets were inoculated with a cocktail of eight STEC and then stored at 5 or 25 °C. At 0, 30, 60, 90 and 120 min post-inoculation, 30 cm(2) of tissue was aseptically excised, followed by selective enumeration of strongly and loosely attached STEC. A significant, though small (0.4 log10 CFU/cm(2)), difference in the numbers of strongly attached cells was observed between non-chilled and chilled briskets (p < 0.05). Significant effects on cell attachment by the interaction of chilling and post-inoculation storage period, or chilling and post-inoculation storage temperature, were identified (p < 0.05). Results indicate beef chilling and post-inoculation storage conditions influenced STEC attachment to beef.
authors.affiliation: Department of Nutrition and Food Science, Texas A&M University, College Station, TX 77843-2253, USA.
authors.forename: Katie R
authors.initials: KR
authors.lastname: Kirsch
authors.affiliation: Department of Animal Science, Texas A&M AgriLife Research, College Station, TX 77843-2471, USA. Electronic address: matt_taylor@tamu.edu.
authors.forename: T Matthew
authors.initials: TM
authors.lastname: Taylor
authors.affiliation: Department of Animal Science, Texas A&M AgriLife Extension, College Station, TX 77843-2471, USA.
authors.forename: Davey
authors.initials: D
authors.lastname: Griffin
authors.affiliation: Department of Animal Science, Texas A&M AgriLife Research, College Station, TX 77843-2471, USA.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Castillo
authors.affiliation: Department of Statistics, University of Nebraska, Lincoln, NE 68588, USA.
authors.forename: David B
authors.initials: DB
authors.lastname: Marx
authors.affiliation: Department of Statistics, University of Nebraska, Lincoln, NE 68588, USA.
authors.forename: Lynette
authors.initials: L
authors.lastname: Smith
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D002417:Cattle; D003080:Cold Temperature; D005506:Food Contamination / Q000032:analysis; D061353:Food Storage / Q000379:methods*; D008460:Meat / Q000032:analysis / Q000382:microbiology*; D054323:Shiga-Toxigenic Escherichia coli / Q000254:growth & development* / Q000502:physiology
keywords: Beef; Chilling; Inoculation; Interventions; Shiga toxin-producing Escherichia coli