Growth of Shiga toxin-producing Escherichia coli (STEC) and impacts of chilling and post-inoculation storage on STEC attachment to beef surfaces

• Published in: Food microbiology 2014-12, Vol.44, p.236-242
• Main Authors: Kirsch, Katie R., Taylor, T. Matthew, Griffin, Davey, Castillo, Alejandro, Marx, David B., Smith, Lynette
• Format: Article
• Language: English
• Subjects: Animals; Bacterial Adhesion; Beef; Biological and medical sciences; Cattle; Chilling; Cold Temperature; Escherichia coli; Food Contamination - analysis; Food industries; Food microbiology; Food Storage - methods; Fundamental and applied biological sciences. Psychology; Inoculation; Interventions; Meat - analysis; Meat - microbiology; Shiga toxin-producing Escherichia coli; Shiga-Toxigenic Escherichia coli - growth & development; Shiga-Toxigenic Escherichia coli - physiology
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2014.06.016

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 cm2 of tissue was aseptically excised, followed by selective enumeration of strongly and loosely attached STEC. A significant, though small (0.4 log10 CFU/cm2), difference in the numbers of strongly attached cells was observed between non-chilled and chilled briskets (p