Listeria monocytogenes, a foodborne pathogen, and other Listeria spp. are present in natural environments. Isolating and characterizing strains from natural reservoirs can provide insight into the prevalence and diversity of Listeria spp. in these environments, elucidate their contribution to contamination of agricultural and food processing environments and food products, and lead to the discovery of novel species. In this study, we evaluated the diversity of Listeria spp. isolated from soil samples in a small region of the Great Smoky Mountains National Park (GSMNP), which is the most biodiverse national park in the United States National Park system. Of the 17 Listeria isolates that were recovered, whole-genome sequencing revealed that 14 were unique strains. The unique strains were shown to represent a diversity of Listeria spp., including L. monocytogenes (n=9), L. cossartiae subsp. cossartiae (n=1), L. marthii (n=1), L. booriae (n=1), and a novel Listeria sp. (n=2). The Listeria isolated in this study were collected from high elevation sites near a creek that drains into a series of rivers ultimately leading to the Mississippi River; thus, the Listeria present in this natural environment could potentially travel downstream to a large region that includes portions of nine southeastern and midwestern states in the U.S. The Listeria spp. isolated and described in this study provide insight into the diversity of Listeria spp. found in the Great Smoky Mountains and indicate that this environment is a reservoir of novel Listeria spp.
Land Snails of Selected Rare High Elevation Forests and Heath Balds of the Great Smoky Mountains National Park
