Listeria fleischmannii sp. nov., isolated from cheese

Abstract

A study was performed on three isolates (LU2006-1T, LU2006-2 and LU2006-3), which were sampled independently from cheese in western Switzerland in 2006, as well as a fourth isolate (A11-3426), which was detected in 2011, using a polyphasic approach. The isolates could all be assigned to the genus Listeria but not to any known species. Phenotypic and chemotaxonomic data were compatible with the genus Listeria and phylogenetic analysis based on 16S rRNA gene sequences confirmed that the closest relationships were with members of this genus. However, DNA–DNA hybridization demonstrated that the isolates did not belong to any currently described species. Cell-wall-binding domains of Listeria monocytogenes bacteriophage endolysins were able to attach to the isolates, confirming their tight relatedness to the genus Listeria . Although PCR targeting the central portion of the flagellin gene flaA was positive, motility was not observed. The four isolates could not be discriminated by Fourier transform infrared spectroscopy or pulsed-field gel electrophoresis. This suggests that they represent a single species, which seems to be adapted to the environment in a cheese-ripening cellar as it was re-isolated from the same type of Swiss cheese after more than 5 years. Conjugation experiments demonstrated that the isolates harbour a transferable resistance to clindamycin. The isolates did not exhibit haemolysis or show any indication of human pathogenicity or virulence. The four isolates are affiliated with the genus Listeria but can be differentiated from all described members of the genus Listeria and therefore they merit being classified as representatives of a novel species, for which we propose the name Listeria fleischmannii sp. nov.; the type strain is LU2006-1T ( = DSM 24998T = LMG 26584T).

Identification of non-Listeria spp. bacterial isolates yielding a β-d-glucosidase-positive phenotype on Agar Listeria according to Ottaviani and Agosti (ALOA)

“…known up until 2010 (L. grayi, L. innocua, L. ivanovii, L. monocytogenes, L. seeligeri, and L. welshimeri) are Grampositive, catalase-positive, oxidase-negative rods, VP-positive, esculinpositive and motile when cultured at 20-25°C (Fraser and Sperber, 1988;Ludwig et al, 2009;Rocourt and Buchrieser, 2007); due to their fermentative metabolism, their growth on F/R slants results on yellowing of the entire tube (yellow slant, yellow butt). L. marthii, L. fleischmannii, L. weihenstephanensis and L. rocourtiae have only recently been described as new species in the Listeria genus (Bertsch et al, 2013;Graves et al, 2010;Halter et al, 2013;Leclercq et al, 2010) and, similar to the six previously known Listeria spp., they were also found to be catalase-positive and esculin-positive. However, with the exception of L. weihenstephanensis which was reported as VP-negative, no information on the VP-test reaction was provided for the other three species.…”

Reservoirs of Listeria Species in Three Environmental Ecosystems

“…nov., and L. riparia sp. nov. (3,4,5,6,7,8). Some Listeria species (L. monocytogenes, L. ivanovii, and L. seeligeri) harbor a gene cluster, Listeria pathogenicity island 1 (LIPI-1), that plays a cardinal role in Listeria virulence (9,10).…”

Outbreak of encephalitic listeriosis in red-legged partridges (Alectoris rufa)

“…The genus Listeria consists of 10 species, two of which have been associated with disease in humans and animals (Orsi et al, 2011;Bertsch et al, 2013;Lang Halter et al, 2013). Disease due to Listeria ivanovii appears to be rare and restricted to ruminants (Low & Donachie, 1997;Orsi et al, 2011).…”