Occurrence of Listeria monocytogenes in Counter-Sliced Turkey Meat Samples from Independent Delis in New York City.

ABSTRACT: Research suggests that small, independent delicatessens are less likely to follow proper sanitation procedures, including slicer inspection, which could lead to a higher likelihood of these delis being a reservoir for Listeria monocytogenes growth and cross-contamination. This study was undertaken to determine the incidence of L. monocytogenes in counter-sliced turkey deli meat obtained from independent delis in an urban city. Deli meat, counter-sliced on site, was collected from 118 independent delis in New York City. The samples were analyzed for L. monocytogenes using the U.S. Department of Agriculture Microbiology Laboratory Guidebook methodology for isolation and confirmation. The selection criteria for delis included using the city's restaurant inspection and grading system. Two samples, from separate delis, were confirmed as positive for L. monocytogenes (1.69%). Analysis of the genomic sequences of one of the samples revealed a close match to a cluster of six clinical isolates, which were part of an ongoing multistate listeriosis outbreak spanning four states. The sequence of the second isolate matched a clinical isolate in a neighboring state. Both isolates were obtained from delis that did not have the top inspection grade. Although a snapshot of one urban area, this study is the first report on the current incidence of L. monocytogenes on counter-sliced deli meat from independent deli establishments. This study suggests that these delis can potentially serve as sources of L. monocytogenes contamination or contribute to downstream foodborne listeriosis. Information provided by city inspection and grading systems, in addition to the letter grade, may serve as a tool to identify delis with potential L. monocytogenes contamination issues and a basis for product and environmental sampling by public health authorities.