<i>Bergeyella anatis</i> sp. nov., isolated from the upper respiratory tract of duck.

Five bacterial strains, designated as RCAD1438, RCAD1439^T, RCAD1670, RCAD1671 and RCAD1672, were isolated from the upper respiratory tract of ducks in Anhui, Shaanxi and Sichuan, China. All strains are Gram-stain-negative, rod-shaped, non-motile, non-spore-forming, aerobic and capsulated. They grow optimally at 37 °C and pH 7.5 and are positive for oxidase and catalase activities. High 16S rRNA gene sequence similarity (>99%) and average nucleotide identity (ANI) values (>96%) confirm that the five strains belong to the same species. Phylogenetic analysis based on 16S rRNA gene sequences indicates that these strains belong to the genus <i>Bergeyella</i> and are closely related to <i>Bergeyella porcorum</i> CECT 9006^T (96.7 %-97.1%) and <i>Bergeyella zoohelcum</i> NBRC 16014^T (96.7 %-97.0%). However, ANI and digital DNA-DNA hybridization values between strain RCAD1439^T and these two type strains, as well as other closely related strains, were no more than 72.0% and 35.0%, respectively, both below the accepted species thresholds. The genomic size of the five strains is 2.4-2.6 Mb, with genomic DNA G+C content of 42.1-42.9 mol%. The major respiratory quinone of strain RCAD1439^T was menaquinone MK-6, and its polar lipid profile includes phosphatidylethanolamine, two unidentified aminolipids, one unidentified aminolipid and six unidentified lipids. Based on physiological, genotypic, phylogenetic and chemotaxonomic data, these five strains represent a novel species of <i>Bergeyella</i>, for which the name <i>Bergeyella anatis</i> sp. nov. is proposed. The type strain is RCAD1439^T (=CCTCC AB 2024048^T=GDMCC 1.4426^T=KCTC 102274^T).