P2-88 Growth and Survival of Salmonella spp. on Whole and Sliced Cucumbers

Tuesday, August 2, 2016
America's Center - St. Louis
Rachel Pfuntner, Virginia Tech, Painter, VA
Laura Truitt, Virginia Tech, Painter, VA
Michelle Danyluk, University of Florida, Lake Alfred, FL
Steven Rideout, Virginia Tech, Painter, VA
Laura Strawn, Virginia Tech, Painter, VA
Introduction: Salmonella outbreaks were associated with cucumbers in 2013, 2014 and 2015. The 2014 Salmonella outbreak in cucumbers caused 275 illnesses and 1 death in 29 U.S. states and Washington DC. Little is known about the behavior of Salmonella on whole and sliced cucumber. 

Purpose: A study was performed to evaluate the growth and survival of Salmonella spp. on whole and sliced cucumbers at different storage conditions. 

Methods: Whole and sliced cucumbers were spot inoculated with a five-strain cocktail of Salmonella. Inoculated samples were air dried, placed in Whirl-pak bags and stored at 4 and 24±2°C. Samples were enumerated on nonselective and selective media following storage for 0, 24, 48, 72, 120 and 168 h and 0, 8, 17, 24, 48 and 72 h for cucumbers held at 4 and 24±2°C, respectively. Population levels (log CFU/g) of Salmonella on cucumber were calculated.  

Results: Salmonella populations significantly increased on whole and sliced cucumbers held at room temperature for the storage period (P<0.05). At 24±2°C, Salmonella populations increased by approximately 2.5 and 3 log CFU/g on whole and sliced cucumbers, respectively. The majority of the growth occurred during the first 17 h. At 4±2°C, Salmonella populations survived for up to 7 d on both whole and sliced cucumber, with an average decrease of 1 log CFU/g.

Significance: Whole and sliced cucumbers are potential vectors for Salmonella transmission. Best practices (GAPs, GHPs) should be followed in the field to limit pre-harvest contamination risk, and the cold chain maintained throughout handling to reduce the likelihood of Salmonella multiplication.