sp. nov., isolated from caecal contents of domestic pigs ().

During the 2021 European Food Safety Authority coordinated harmonized monitoring of antimicrobial resistance in species in Slovenia, five -like strains were cultured from caeca of a total of 104 domestic pigs that could not be identified using the standard-prescribed biochemical tests or MALDI-TOF MS. The isolates were obtained using the standard ISO 10272 procedure for the isolation of thermotolerant with prolonged cultivation time. Small -like colonies were observed on mCCDA and CASA agar plates after 2-4 days of incubation; dark-field microscopy revealed relatively big spirilli-shaped bacteria exhibiting characteristic -like motility. The cells were 1.5-3 µm long and 0.5-0.7 µm wide, Gram-negative, oxidase-positive and catalase-positive. MALDI-TOF mass spectra were distinctive and consistent, but with low MALDI-TOF MS log scores and the closest matches being those of and . All five strains underwent whole-genome sequencing. Analysis of 16S rRNA gene sequences revealed that the isolates were most similar (98.3-98.4 % identity) to . Pairwise average nucleotide identity (ANI) values revealed that the five studied strains shared pairwise ANI of 96.2-96.5 % but were clearly distinct from the previously described species (ANI ≤72.8 %). The core genome-based phylogeny confirmed that the new strains form a distinct and well-supported clade within the genus . The conducted polyphasic taxonomic analysis confirmed that the five strains represent a novel species for which the name sp. nov. is suggested, with strain 46386 (=DSM 115534=CCUG 76865) as the type strain.