Adenosine Triphosphate Bioluminescence is a Poor Indicator of Listeria spp. Presence in Distribution Centers Handling Fresh Produce

Monitoring for residual ATP is a rapid method used throughout the food industry to verify the efficacy of cleaning procedures for removing organic material prior to sanitation. Efforts to use ATP readings as a predictor of foodborne pathogens within the food environment were examined with mixed results. Therefore, ATP was investigated as an indicator for the presence of Listeria species in 17 U.S. food distribution center environments. Environmental surface samples (n = 300) were collected concurrently with ATP swabs to determine Listeria spp. presence and ATP relative light units (RLU) at given sampling sites. The number of Listeria spp.-positive samples were 13 (4.3%) of 300. ATP RLU varied widely across individual distribution centers, with an average of ca. 559 RLU and an overall range of ca. 0 to 8,690 RLU. Logistic regression to predict Listeria spp.-positive sample versus log(x + 1) transformed RLU data provided an odds ratio of 0.34; this indicates that ATP bioluminescence was a poor predictor of Listeria species presence in the sampled distribution centers. Although ATP does not appear to be a predictor of Listeria spp., it still may be an important tool to monitor and verify the efficacy of sanitation programs.