Listeria monocytogenes at the human–wildlife interface: black bears (Ursus americanus) as potential vehicles for Listeria. Issue 3 (11th November 2019)

• Record Type: Journal Article
• Authors: Parsons, Cameron; Niedermeyer, Jeff; Gould, Nicholas; Brown, Phillip; Strules, Jennifer; Parsons, Arielle W.; Bernardo Mesa‐Cruz, J.; Kelly, Marcella J.; Hooker, Michael J.; Chamberlain, Michael J.; Olfenbuttel, Colleen; DePerno, Christopher; Kathariou, Sophia
• Is Part Of: Microbial biotechnology. Volume 13:Issue 3(2020:May)
• Page Start: 706
• Page End: 721
• Publication Date: 2019-11-11
• Subjects: Microbial biotechnology -- Periodicals; Biotechnology; Microbiology; 660.62
• DOI: 10.1111/1751-7915.13509
• Languages: English
• ISSNs: 1751-7915

Abstract

Summary: Listeria monocytogenes is the causative agent of the foodborne illness listeriosis, which can result in severe symptoms and death in susceptible humans and other animals. L. monocytogenes is ubiquitous in the environment and isolates from food and food processing, and clinical sources have been extensively characterized. However, limited information is available on L. monocytogenes from wildlife, especially from urban or suburban settings. As urban and suburban areas are expanding worldwide, humans are increasingly encroaching into wildlife habitats, enhancing the frequency of human–wildlife contacts and associated pathogen transfer events. We investigated the prevalence and characteristics of L. monocytogenes in 231 wild black bear capture events between 2014 and 2017 in urban and suburban sites in North Carolina, Georgia, Virginia and United States, with samples derived from 183 different bears. Of the 231 captures, 105 (45%) yielded L. monocytogenes either alone or together with other Listeria . Analysis of 501 samples, primarily faeces, rectal and nasal swabs for Listeria spp ., yielded 777 isolates, of which 537 (70%) were L. monocytogenes. Most L. monocytogenes isolates exhibited serotypes commonly associated with human disease: serotype 1/2a or 3a (57%), followed by the serotype 4b complex (33%). Interestingly, approximately 50% of the serotype 4b isolates had the IVb‐v1 profile, associated with emerging clones of L. monocytogenes. Thus, black bears may serve as novel vehicles for L. monocytogenes, including potentially emerging clones. Our results have significant public health implications as they suggest that the ursine host may preferentially select for L. monocytogenes of clinically relevant lineages over the diverse listerial populations in the environment. These findings also help to elucidate the ecology of L . monocytogenes and highlight the public health significance of the human–wildlife interface. Abstract : Listeria monocytogenes has been extensively studied in food‐processing environments; however, key elements regarding its ecology and reservoirs in the natural environment remain largely uncharacterized. We sampled black bears in the southeastern United States from 2014 to 2017, recovering 777 Listeria spp. isolates, of which most were L. monocytogenes of serotypes commonly encountered in human listeriosis. Our results suggest a potential role for black bears in dissemination and adaptation of L. monocytogenes, with the greatest public health implications in regions of direct overlap between black bears and humans. Urban areas are expanding in the US and other nations, with humans increasingly encroaching into wildlife habitats and enhancing the frequency of human‐wildlife contacts and associated pathogen transfer events. Elucidation of L. monocytogenes harbored in wildlife species will address major gaps in our understanding of the ecology of this pathogen, and will better inform the development of strategies to reduce the risk for listeriosis.