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Development of a bacteriophage cocktail to control the top seven Vero-toxin E. coli serotypes on fresh produce

Investigators
Narvaez, Claudia
Institutions
University of Manitoba
Start date
2015
End date
2018
Objective

The major goal of this project is to develop and evaluate a bacteriophage cocktail capable of counteracting contamination by the seven VTEC E. coli serotypes on fresh produce and sprouts seeds.

The specific objectives are:

  1. To assemble a bacteriophage cocktail against the top seven VTEC for testing at different temperatures ( 5, 10 or 25 °C)
  2. To evaluate phage cocktail effectiveness on produce surfaces and sprouts seeds which have been previously inoculated with VTEC E. coli cocktails at environmental temperatures and refrigerated storage during 24, 48 and 72 hours in aerobic sealed bags.
  3. To evaluate phage cocktails and sodium calcium hypochlorite effectiveness aimed at eliminating STEC serotypes on produce surfaces and seeds under storage conditions as mentioned above.
  4. To evaluate the effectiveness of VTEC phage cocktail when combined with a commercial Salmonella phage cocktail (Salmofresh).
More information

Leafy greens have been linked with the emergence of Vero-toxin E. coli serotype outbreaks. The objectives of this proposal will be to assemble and determine the effectiveness of bacteriophage cocktails against the top 7 VTEC (O26, O45, O103, O111, O121 and O145 and O157) in adulterated sprouts and lettuce. Five treatments will be applied to leaves/sprouts samples: T1: sample controls; T2: samples VTEC inoculated; T3: samples VTEC inoculated + chlorinated water washing; T4: samples VTEC inoculated + phages cocktails; T5: samples VTEC inoculated + chlorinated water + phages cocktails. Treatments will be packaged in sterile bags and stored at 5, 10 and 25°C for 24, 48 and 72 hours. At each storage period, conventional and molecular microbiology techniques will be used for VTEC screening and confirmation. This intervention has the potential to be adopted by industry in order to decrease the foodborne risks associated with fresh produce consumption.

Funding Source
Ontario Min. of Agriculture Food and Rural Affairs
Project number
FS2014-2294
Categories
Escherichia coli
Salmonella
Natural Toxins