Appl Microbiol Biotechnol DOI 10.1007/s00253-016-7552-2

MINI-REVIEW

Characteristics and distribution of spp., including Listeria species newly described since 2009

Renato H. Orsi1 & Martin Wiedmann1

Received: 15 January 2016 /Revised: 11 April 2016 /Accepted: 14 April 2016 # The Author(s) 2016. This article is published with open access at Springerlink.com

Abstract The genus Listeria is currently comprised of 17 Keywords Listeria . Listeria sensu strictu . Listeria sensu species, including 9 Listeria species newly described since lato . New species . New genus 2009. Genomic and phenotypic data clearly define a distinct group of six species (Listeria sensu strictu) that share common phenotypic characteristics (e.g., ability to grow at low temper- Introduction ature, flagellar motility); this group includes the pathogen . The other 11 species (Listeria sensu The genus Listeria currently includes 17 recognized species lato) represent three distinct monophyletic groups, which may (Listeria monocytogenes, , , warrant recognition as separate genera. These three proposed Listeria welshimeri, Listeria marthii, , genera do not contain pathogens, are non-motile (except for Listeria grayi, Listeria fleischmannii, Listeria floridensis, Listeria grayi), are able to reduce nitrate (except for Listeria Listeria aquatica, Listeria newyorkensis, Listeria cornellensis, floridensis), and are negative for the Voges-Proskauer test (ex- Listeria rocourtiae, Listeria weihenstephanensis, Listeria cept for L. grayi). Unlike all other Listeria species, species in grandensis, Listeria riparia,andListeria booriae)ofsmall the proposed new genus Mesolisteria are not able to grow rod-shaped gram-positive . Only two of these species, below 7 °C. While most new Listeria species have only been L. monocytogenes and L. ivanovii, are considered pathogens. identified in a few countries, the availability of molecular tools L. monocytogenes is an important human foodborne pathogen for rapid characterization of putative Listeria isolates will like- and the third leading cause of foodborne deaths due to micro- ly lead to future identification of isolates representing these bial causes in the USA (Scallan et al. 2011). Human disease new species from different sources. Identification of Listeria cases and outbreaks caused by this organism have a consider- sensu lato isolates has not only allowed for a better under- able economic impact for society and the food industry (Ivanek standing of the evolution of Listeria and virulence character- et al. 2004). In addition, the food industry as well as regulatory istics in Listeria but also has practical implications as detec- agencies around the world perform a large number of tests, of tion of Listeria species is often used by the food industry as a food and environmental samples, for L. monocytogenes and marker to detect conditions that allow for presence, growth, Listeria spp.; hence, sales of test kits for these organisms are and persistence of L. monocytogenes. This review will provide an important revenue for a number of companies. Importantly, a comprehensive critical summary of our current understand- detection of Listeria species is often used by the food industry ing of the characteristics and distribution of the new Listeria as a marker to detect conditions that allow for presence, growth, species with a focus on Listeria sensu lato. and persistence of L. monocytogenes. Hence, identification of new Listeria species and changes in the of Listeria can have considerable impacts on food industry and test kit * Martin Wiedmann manufacturers. [email protected] El