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Tracing Pathogen Contamination through the Post-Harvest Environment

Objective

Raw beef has been shown to represent a potential source of contamination for the consumer. Hides
containing pathogens such as E. coli O157:H7 or Salmonella are among the principal sources of
pathogens contaminating carcasses. This contamination mechanism is generally considered a
direct transmission from the hide onto the carcass. However, the plant environment may serve as
an indirect source of transmission, from the hide to surfaces which may become niches serving as
a source for further transfer onto the carcass. This project utilized novel marker organisms to
determine if transmission could occur from inoculated hides via environmental sources (walls,
floors, general equipment, personal equipment) onto the carcass, and from the carcass with the
inoculated hide to subsequent carcasses
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The object of this study consisted of inoculating the hide of beef cattle at slaughter with fluorescent
nonpathogenic bacteria as surrogates for E. coli O157:H7 and Salmonella. The study was conducted
at 3 different abattoirs with the objective of identifying the impact of the post-harvest processing
environment on pathogen contamination.

More information

Findings: The study was conducted at 3 different abattoirs with the objective of identifying the impact of the post-harvest processing environment on pathogen contamination. Results demonstrated that cross-contamination did occur from the inoculated hide to the carcass, and to subsequent carcasses, as well as from hides or carcasses to the plant environment, personnel garments and equipment. The presence of the pathogen surrogates in environmental samples, although sporadic, indicates that pathogens can be transferred from a contaminated animal to the processing environment during hide removal. For all carcasses that were sampled, the pathogen surrogates were reduced to below detectable levels following the in-plant antimicrobial intervention.

Investigators
Villarreal, Mariana ; Savell, Jeffrey; Lucia, Lisa; Ilhak, Irfan; Harris, Kerri; Genho, Daniel; Castillo, Alejandro; Dickson, James
Institution
Iowa State University
Texas A&M University
Start date
2008
End date
2009
Project number
BC-2008-15