sp. nov., isolated from the upper respiratory tract of duck.

Five bacterial strains, designated as RCAD1438, RCAD1439T, 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 Bergeyella and are closely related to Bergeyella porcorum CECT 9006T (96.7 %-97.1%) and Bergeyella zoohelcum NBRC 16014T (96.7 %-97.0%). However, ANI and digital DNA-DNA hybridization values between strain RCAD1439T 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 RCAD1439T 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 Bergeyella, for which the name Bergeyella anatis sp. nov. is proposed. The type strain is RCAD1439T (=CCTCC AB 2024048T=GDMCC 1.4426T=KCTC 102274T).