“They’re family members, and they have similar growth environments, conditions and preferences,” she said. “We assume if we find Listeria that the conditions could possibly be right for Listeria monocytogenes to be there.”
Chapman will analyze the meta data to see if he can correlate positive finds at different facilities to commonalities. As part of the analysis, he’ll look at a myriad of variables, including on-site management practices, employee shifts, facility design, sanitation practices and sanitation materials.
As originally proposed, Dunn and colleagues were to visit at least 25 DCs throughout the nation to collect samples by swabbing numerous surfaces from Zones 2 through 4. Those areas don’t contact produce directly but are farther removed, such as pallets, forklift tires, floors, floor cracks, truck trailers and employee shoes.
Then the COVID-19 pandemic hit in March, and two of the three researchers are still under travel restrictions. As of this writing, they’ve collected samples from 11 DCs, and most of that sampling was before the pandemic.
Although the researchers had hoped to visit cooperating California DCs, Dunn said they may settle with operations east of the Mississippi River. So far, they’ve visited facilities in Texas, Michigan and New York and are trying to recruit one more partner from Florida, Georgia or Alabama, she said. Michelle Danyluk, Ph.D., with the University of Florida, has helped by collecting samples from DCs in her state.
What has made the project possible is the input and cooperation from participating DCs, Dunn said. In fact, distribution center representatives were the ones who brought their concerns to the Center for Produce Safety initially.
“We couldn’t do the work without them,” Dunn said. “This was one of the CPS target areas a couple years ago, and it was because our partners brought it forward. If they weren’t onboard, we couldn’t have brought this forward. Our partners have been a huge help. They conceived the idea, were instrumental in the project design and have been so accommodating in getting us into the facilities.”
She said the DCs wanted to be proactive, identify any potential risks and take care of them before they became issues.
Despite the COVID-19 challenges, Dunn said the researchers have been able to collect a substantial number of samples from each facility, and they should be able to put together a “nice packet of information” that will benefit DCs.