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United States Department of Agriculture

Agricultural Research Service

Research Project: Role of Bacterial Surface Appendages in Attachment and Internalization of Escherichia Coli O157:h7 on Organic Leafy Greens

Location: Environmental Microbial and Food Safety Laboratory

Project Number: 1245-32420-005-41
Project Type: Specific Cooperative Agreement

Start Date: Jan 01, 2013
End Date: Jun 30, 2014

Objective:
The objective of this cooperative research project is to elucidate mechanisms by which foodborne pathogens such as Escherichia coli O157:H7 may attach to and internalize in organic leafy greens and attach to equipment surfaces commonly used for harvesting and to evaluate the efficacy of alternative pre- and post-harvest interventions that can improve shelf-life and control pathogenic microbial growth and survival on organic leafy greens.

Approach:
The general approach of this cooperative research project will determine the attachment and biofilm forming properties of E. coli O157:H7 on leafy greens. Surface charge and hydrophobicity measurements will be done and attachment will be viewed under confocal scanning laser microscope (CSLM). The role of curli and cellulose in attachment, internalization, and biofilm formation on organic leafy greens will be evaluated under a controlled environment. Leaf surface structure, leaf roughness, and 3-D image analysis of leaves of commonly used leafy green cultivars will be compared to evaluate pathogen attachment. Field experiments will be conducted as needed to determine the effect of cultivars on E. coli O157:H7 attachment on organic leafy greens. The efficacy of several plant derived antimicrobials will be evaluated in reducing or inactivating pathogenic and microorganisms on equipment used during harvest. Novel MBEC and CDC-bioreactor assays will be employed to evaluate biofilm removing capacity of natural antimicrobials.

Last Modified: 7/30/2014
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