Vibrio atypicus sp. nov., isolated from the digestive tract of the Chinese prawn (Penaeus chinensis O'sbeck)

A culture (designated strain HHS02T) was isolated from Chinese prawn (Penaeus chinensis, O'sbeck) and determined to be a member of the genus Vibrio. Strain HHS02T comprised slightly curved, rod-shaped, non-endospore-forming, Gram-negative, catalase-negative, oxidase-positive, O/129-sensitive and facultatively anaerobic cells that were motile by means of a single polar flagellum. Growth of strain HHS02T occurred in 0.5–7 % (w/v) NaCl [optimally in 1–3 % (w/v) NaCl] and between pH 7.0 and 10.0 (optimally at pH 8.0–9.0). The strain showed growth between 16 and 30 °C (optimum 20 °C). Analysis using the 16S rRNA, gapA, gyrB, mreB, pyrH, recA and topA gene sequences of the novel isolate revealed that the organism belonged to the genus Vibrio, with ∼98, 98, 90, 88, 92, 89 and 83 % sequence similarity, respectively, with representatives of the genus Vibrio. DNA–DNA hybridization experiments indicated that the novel strain was distinct from recognized species of the genus Vibrio. The major fatty acid components were summed feature 3 (C16 : 1 ω7c and/or iso-C15 : 0 2-OH, 38.7 %), C16 : 0 (22.9 %) and C18 : 1 ω7c (12.5 %). The G+C content of the genomic DNA was 44.4 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, it is concluded that strain HHS02T should be classified as a novel species of the genus Vibrio, for which the name Vibrio atypicus sp. nov. is proposed. The type strain is HHS02T (=CGMCC 1.8461T=LMG 24781T).