title: Translocation and cross-contamination of E. coli O157 in beef eye-of-round subprimal cuts processed with high-pressure needleless injection.
abstract: High-pressure needleless injection (HPNI) is an emerging enhancing process where small-diameter, high-velocity bursts of liquid penetrate soft foods at pressures up to 69 MPa. The incidence and depth of translocated surface-inoculated E. coli O157 in HPNI-processed beef eye-of-round subprimal cuts was determined. HPNI translocated E. coli O157 from the surface to the interior of the eye-of-round subprimal cuts with incidence of 40% (± 7%), 25% (± 8%), and 25% (± 8)% for subprimals that had been surface-inoculated with a 4-strain cocktail at 0.5, 1, and 2 log₁₀ CFU/cm² , respectively. The run-off water was collected and found to contain 2, 2, and 3 log₁₀ CFU/mL E. coli O157. The runoff was reused for HPNI of additional subprimals, and this resulted in a cross-contamination incidence of 83% (± 4%), 60% (± 15%), and 37% (± 6)%. Incidence of translocation and cross-contamination was similar at 0 to 1, 1 to 2, 2 to 3, 3 to 4, 4 to 6, and 6 to 8 cm below the inoculated surface. Results indicate that surface microbiota on beef will be carried to the interior of HPNI-processed beef by initial translocation from the surface with the injected fluid and by cross-contamination with recycled fluid.
  
  
  CONCLUSIONS
  This research has practical relevance for the beef enhancement process called high-pressure needleless injection. The process's effect on surface bacteria on beef was studied.
authors.affiliation: Dept of Nutrition, Dietetics and Food Sciences Utah State Univ, 8700 Old Main Hill, Logan, UT 84322-8700, USA. laura_jefferies@byu.edu
authors.forename: Laura K
authors.initials: LK
authors.lastname: Jefferies
authors.forename: Conly L
authors.initials: CL
authors.lastname: Hansen
authors.forename: Frost M
authors.initials: FM
authors.lastname: Steele
mesh_terms: D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial; D004866:Equipment Contamination; D019453:Escherichia coli O157 / Q000254:growth & development* / Q000302:isolation & purification; D005503:Food Additives / Q000008:administration & dosage*; D005517:Foodborne Diseases / Q000517:prevention & control; D007277:Injections, Jet; D008460:Meat / Q000382:microbiology*; D008462:Meat-Packing Industry / Q000295:instrumentation / Q000379:methods*; D059027:Recycling; D013499:Surface Properties; D014589:Utah
chemical_list: D005503:Food Additives