title: Aerobic plate counts and ATP levels correlate with Listeria monocytogenes detection in retail delis.
abstract: Listeria monocytogenes is a foodborne pathogen that causes an estimated 1,591 cases of illness and 255 deaths annually in the United States, the majority of which are attributed to ready-to-eat deli meats processed in retail delis. Because retail delis distribute product directly to consumers, rapid methods to validate cleaning and sanitation are needed to improve retail food safety. This study investigated the relationships among ATP levels, standard aerobic plate count (APC), and L. monocytogenes presence in fully operational delis. Fifteen full-service delis were concurrently sampled for ATP, APC, and L. monocytogenes during preoperational hours once monthly for 3 months. Fifteen additional delis were recruited for 6 months of operational sampling (n = 30). A 1-log increase in APC was equivalent to a 3.3-fold increase in the odds of detecting L. monocytogenes (P < 0.001) and a 1.9-log increase in L monocytogenes population (P = 0.03). An ATP level increase of 1 log relative light unit correlated to a 0.22-log increase in APC (P < 0.001). A preoperational ATP level mean increase by 1 log relative light unit increased the odds of detecting L. monocytogenes concurrently fourfold. A 0.5-log increase in mean ATP level during preoperational sampling corresponded to a 2% increase in the predicted L. monocytogenes prevalence during operation (P < 0.01). Additionally, 10 statistically representative sites were identified and recommended for use in sanitation monitoring programs. Our data support the use of ATP as a rapid method to validate effective cleaning and sanitation to reduce L. monocytogenes in retail delis.
authors.affiliation: Department of Food Science, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Susan R
authors.initials: SR
authors.lastname: Hammons
authors.affiliation: Department of Food Science, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Stasiewicz
authors.affiliation: Department of Food Science, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Sherry
authors.initials: S
authors.lastname: Roof
authors.affiliation: Department of Food Science, Purdue University, West Lafayette, Indiana 47907, USA. hfoliver@purdue.edu.
authors.forename: Haley F
authors.initials: HF
authors.lastname: Oliver
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis*; D058491:Bacterial Load; D003257:Consumer Product Safety; D005516:Food Microbiology; D059022:Food Safety; D006801:Humans; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D008088:Listeriosis / Q000453:epidemiology / Q000382:microbiology; D008461:Meat Products / Q000032:analysis / Q000382:microbiology*; D012147:Restaurants; D012499:Sanitation; D014481:United States
chemical_list: D000255:Adenosine Triphosphate