Is it a Listeria sensu stricto or sensu lato species? Why understanding the difference is important

Webinar Description

Organized by: The Applied Laboratory Methods PDG and Merieux NutriSciences

The Listeria genus has rapidly expanded since 2009 from six to 28 species. Comparative characterization of Listeria clearly indicated the existence of two distinct groups that are now formally known as the Listeria (i) sensu stricto, and (ii) sensu lato. The Listeria sensu stricto consists of L. monocytogenes (LM) and the species that indicate a potential for LM contamination; this group now contains 10 species. The Listeria sensu lato, which initially only included L. grayi, has now grown to 18 species. Arguably, all of the Listeria sensu lato species are divergent enough from the Listeria sensu stricto to warrant reclassification as separate genera. Therefore, when a Listeria spp. detection method is reported to “not detect all species”, it is important to evaluate if it is a sensu stricto or a sensu lato that is not detected as this distinction has different implications for food safety.

Learning Objectives:
-Review why genomics data supports a re-organization of Listeria and that only the Listeria sensu stricto species should be classified as a Listeria
-Clarify the expectations for detecting all Listeria spp. using the currently available rapid detection and identification methods.
-Understand the FDA's perspective on detecting the new Listeria species

Professional Development Groups

  • Applied Laboratory Methods Professional Development Group


  • Martin Wiedmann, Presenter Cornell University
  • Yi Chen, Presenter Food and Drug Administration (FDA)
  • Catharine Carlin, Presenter Merieux NutriSciences
  • Sarita Raengpradub, Moderator Merieux NutriSciences