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

Abstract

A culture (laboratory reference number = HHS02T) was isolated from Chinese prawn (Penaeus chinensis, O’ sbeck) and equated with a species in the genus Vibrio. HHS02T comprised slightly curved rod-shaped, non-endospore-forming, Gram-negative, catalase-negative, oxidase-positive, O/129 sensitive, facultatively anaerobic cells that were motile by means of single polar flagella. 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 30ºC (optimum growth temperature = 20ºC). Analysis using the 16S rRNA, gapA, gyrB, mreB, pyrH, recA and topA gene sequences of the isolate revealed that the organism belongs to the genus Vibrio, with ~98, 98, 90, 88, 92, 89 and 83% sequence similarity with representatives of the genus Vibrio, respectively. The major fatty acid components are C16:1ω7c and/or iso-C15:0 2-OH (46.06%), C16:0 (19.07%) and C18:1ω7c (18.65%), and the G+C content of the genomic DNA is 44.4 mol%. Phylogeny based on 16S rRNA, gapA, gyrB, mreB, pyrH, recA and topA gene sequences, together with data from physiological and biochemical characterizations, demonstrate that strain HHS02T should be classified as a novel species of Vibrio, for which the name Vibrio atypicus sp. nov. is proposed, with the type strain HHS02T (= CGMCC1.8461T = LMG 24781T).