Listeria goaensis sp. nov, a mangrove inhabitant. Listeria goaensis sp. nov, a mangrove inhabitant

Sixteen Listeria-like isolates, obtained from mangrove swamps of Goa, India, could not be taxonomically assigned to any known listerial species. Eight representative isolates were analysed in greater detail using polyphasic analysis and whole genome sequencing (WGS). The bacteria were morphologically short rods, Gram-positive and non-spore forming, that were non-motile, oxidase-negative and catalase-positive, exhibiting weak hemolysis on 5% sheep blood agar plates. The overall fatty acid composition was characteristic of Listeria species, with quantitative differences in iso C15:0, anteiso C15:0, iso C16:0, C16:0, iso C17:0 and anteiso C17:0 fatty acid profiles. The 16S rRNA gene sequence exhibited 93.7-99.7 % nucleotide identity to other listerial species and had less than 92% nucleotide identity to species from closely related genera, indicating that they were de facto members of the genus Listeria. Phylogeny based on either four housekeeping genes or the amino acid sequences of 557 core coding DNA sequences (CDS), grouped these eight isolates in an independent clade within the species Listeria. WGS-based average nucleotide identity and in-silico DNA-DNA hybridization values were lower than the recommended cutoff of 95% and 70% respectively to the other Listeria species, indicating that these eight isolates are representatives of a novel Listeria species. We suggest the name Listeria goaensis sp. nov. be created and assigned to the representative isolate ILCC801T (KCTC 33909; MCC 3285).