sp. nov., isolated from chickens with spotty liver disease.

A novel species of was isolated from bile samples of chickens with spotty liver disease in Australia, making it the second novel species isolated from chickens with the disease, after was isolated and described in 2016. Six independently derived isolates were obtained. They were Gram-stain-negative, microaerobic, catalase-positive, oxidase-positive and urease-negative. Unlike most other species of the genus , more than half of the tested strains of this novel species hydrolysed hippurate and most of them could not reduce nitrate. Distinct from , many of the isolates were sensitive to 2,3,5-triphenyltetrazolium chloride (0.04%) and metronidazole (4 mg ml), and all strains were sensitive to nalidixic acid. Phylogenetic analysis using 16S rRNA and gene sequences demonstrated that the strains formed a robust clade that was clearly distinct from recognized species. Whole genome sequence analysis of the strains showed that the average nucleotide identity and the genome blast distance phylogeny values compared to other species were less than 86 and 66%, respectively, which are below the cut-off values generally recognized for isolates of the same species. The genome of the novel species has a DNA G+C content of 30.6 mol%, while that of is 27.9 mol%. Electron microscopy showed that the cells were spiral-shaped, with bipolar unsheathed flagella. The protein spectra generated from matrix-assisted laser desorption/ionization time of flight analysis demonstrated that they are different from the most closely related species. These data indicate that the isolates belong to a novel species, for which the name sp. nov. is proposed. The type strain is VicNov18 (=ATCC TSD-231=NCTC 14611).