Abstract:
Two Listeria -like isolates obtained from mangrove swamps in Goa, India were characterized using polyphasic combinations of phenotypic, chemotaxonomic and whole-genome sequence (WGS)-based approaches. The isolates presented as short, non-spore-forming, Gram-positive rods, that were non-motile, oxidase-negative, catalase-positive and exhibited alpha-haemolysis on 5 percent sheep- and horse-blood agar plates. The 16S rRNA gene sequences exhibited 93.7–99.7 percent nucleotide identity to other Listeria species and had less than 92 percent nucleotide identity to species of closely related genera, indicating that the isolates are de facto members of the genus Listeria . Their overall fatty acid composition resembled that of other Listeria species, with quantitative differences in iso C sub(15:0), anteiso C sub(15:0), iso C sub(16:0), C sub(16:0), iso C sub(17:0) and anteiso C sub(17:0) fatty acid profiles. Phylogeny based on 406 core coding DNA sequences grouped these two isolates in a monophyletic clade within the genus Listeria . WGS-based average nucleotide identity and in silico DNA–DNA hybridization values were lower than the recommended cut-off values of 95 and 70 percent, respectively, to the other Listeria species, indicating that they are founding members of a novel Listeria species. We suggest the name Listeria goaensis sp. nov. be created and the type strain is ILCC801 sup(T) (=KCTC 33909;=DSM 29886;=MCC 3285).
