Luke D Peterson

University of Wisconsin, Madison, Madison, MS, United States

Are you Luke D Peterson?

Claim your profile

Publications (3)7.09 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: There have been significant outbreaks of listeriosis associated with consumption of contaminated ready-to-eat (RTE) turkey meat products. In this study, we investigated whether growth on RTE deli turkey meat sends environmental signals to listerial cells that makes them more virulent in the gastrointestinal tract of mice. L. Listeria monocytogenes strain F2365 grew from a starting inoculum of 10(3) CFU/mL to final numbers of 10(8)-10(9) CFU/mL (within 12 days at 10 degrees C) when inoculated onto sliced processed, or whole muscle, turkey breast, or into emulsified whole turkey breast. We did not observe any difference in the numbers of CFU recovered from the spleens and livers of A/J mice inoculated intragastrically with L. monocytogenes grown on sliced turkey meat, in emulsified turkey meat, or in brain heart infusion broth. These results suggest that growth on RTE sliced deli turkey, or in RTE emulsified deli turkey, does not enhance the ability of L. monocytogenes F2365 to cause gastrointestinal listeriosis in intragastrically challenged A/J mice.
    International Journal of Food Microbiology 06/2008; 126(1-2):112-5. · 3.43 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ready-to-eat (RTE) deli meats have been categorized as high-risk foods for contraction of foodborne listeriosis. Several recent listeriosis outbreaks have been associated with the consumption of RTE deli turkey meat. In this study, we examined whether the growth of Listeria monocytogenes F2365 on commercially prepared RTE deli turkey meat causes listerial cells to become more resistant to inactivation by synthetic gastric fluid (SGF). Listerial cells grown on turkey meat to late logarithmic-early stationary phase were significantly more resistant to SGF at pH 7.0, 5.0, or 3.5 than listerial cells grown in brain heart infusion (BHI) broth. The pH was lower in the fluid in packages of turkey meat than in BHI broth (6.5 versus 7.5). However, listerial cells grown in BHI broth adjusted to a lower pH (6.0) did not exhibit enhanced resistance to SGF. The lesser resistance to SGF of listerial cells grown in BHI broth may be due, in part, to the presence of glucose (0.2%). This study indicates the environment presented by the growth of L. monocytogenes on deli turkey meat affects its ability to survive conditions it encounters in the gastrointestinal tract.
    Journal of food protection 12/2007; 70(11):2589-95. · 1.83 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although multistrain cocktails of Listeria monocytogenes are used in food inoculation experiments, no studies, to our knowledge, have been reported that use these cocktails in an intragastric mouse model. In this study, we used a five-strain L. monocytogenes cocktail consisting of strains Scott A, MFS108, 101M, V7, and 310 and a four-strain L. monocytogenes cocktail containing strains Scott A, EGD, H7738, and F2365. Here, we report that intragastric inoculation of anesthetized mice with approximately 106 CFU of a cocktail of L. monocytogenes strains does not result (P > 0.05) in a more severe infection (on the basis of the CFU of Listeria spp. recovered from the spleen, liver, and blood) than inoculation of mice with similar numbers of the individual strains comprising the cocktail. Nor did we observe any consistent relationship between susceptibility of L. monocytogenes strains to inactivation in synthetic gastric fluid in vitro and virulence in mice.
    Journal of food protection 11/2006; 69(11):2664-70. · 1.83 Impact Factor

Publication Stats

13 Citations
7.09 Total Impact Points

Institutions

  • 2006–2008
    • University of Wisconsin, Madison
      • Department of Pathobiological Sciences
      Madison, MS, United States