Navigation

P3-222 Persistence of Escherichia coli on Field-grown Tomatoes Inoculated with Contaminated Water Spray

Wednesday, July 12, 2017
Exhibit Hall (Tampa Convention Center)
Chanelle White , University of Maryland Eastern Shore , Princess Anne , MD
Fawzy Hashem , University of Maryland Eastern Shore , Princess Anne , MD
Patricia Millner , USDA ARS Environmental Microbial and Food Safety Laboratory , Beltsville , MD
Joseph Haymaker , University of Maryland Eastern Shore , Princess Anne , MD
Annette Kenney , University of Maryland Eastern Shore , Princess Anne , MD
Lorna Graham , University of Maryland Eastern Shore , Princess Anne , MD
Introduction: According to the Centers for Disease Control and Prevention (CDC), fresh produce attributed to 46% of all foodborne illnesses in the United States that occurred from 1998 to 2008. Contamination of fresh produce can arise during any of several points in the production process including irrigation. Water used for irrigation and agricultural spray has been identified in the FDA Produce Safety rule as a potential source of produce contamination.

Purpose: To investigate the survival of total coliforms and generic Escherichia coli (gEc) populations on field-grown tomatoes irrigated with contaminated water.

Methods: In fall of 2015 and summer of 2016, tomato seedlings (variety: BHN 602 VFFF Hybrid) were transplanted into the field in complete randomized block experiments with four treatments and three replications/treatment. At breaker stage where fruits were pink/red-ripe, plants were spray-inoculated 10-days before final harvest with non-chlorinated water containing fresh bovine manure to achieve four target cell population treatments of 0, 100, 1000, and 10000 gEc/100mL. On days 0 (pre- and post-inoculation), 1, 3, 5, 7, and 9, populations of total coliforms and gEc were determined from tomato fruits (n=15/plot).

Results: In fall of 2015, populations of total coliforms and gEc ranged from 2.58 to 4.95 and 0 to 3.14 CFU/g, respectively, for tomatoes at all stages of ripeness. In summer 2016, total coliforms and gEc populations ranged from 2.27 to 4.20 CFU/g and 0 to 1.48 CFU/g, respectively. Results from both years showed that inoculation dosage had no significant (P < 0.05) effect on survival of total coliforms and gEc on tomato fruits.

Significance: Results indicate that unspecified environmental factors can influence total coliforms and gEc survival on tomato fruits prior to harvest; these factors remain to be clarified.

Back to: Poster Session 3 – Low-water Activity Foods, Packaging, Produce, Microbial Food Spoilage, Antimicrobials, Laboratory and Detection Methods, Water
<< Previous Abstract | Next Abstract >>