Vibrio species are well known as motile, mostly oxidase-positive, facultative anaerobic Gram-negative bacteria. They are abundant in aquatic environments and are a common cause of human infections including diarrhea, soft tissue diseases, and bacteremia. Here, two Gram-negative bacteria, designated M12-1144T and M12-1181, were isolated from human clinical specimens and identified using a polyphasic taxonomic approach. Phylogenetic study based on 16S rRNA gene sequence analysis revealed that the isolates belong to the genus Vibrio, and are closely related to Vibrio metschnikovii KCTC 32284T (98.3%) and Vibrio cincinnatiensis KCTC 2733T (97.8%). The major fatty acids were summed feature 3 (C16:1 ω7c/C16:1 ω6c, 38.0%), C16:0 (23.0%), and summed feature 8 (C18:1 ω7c or C18:1 ω6c, 19.3%) and major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The G + C content of the genomic DNA was determined to be 44.1 mol%. DNA-DNA relatedness between the two newly isolated strains and V. metschnikovii KCTC 32284T and V. cincinnatiensis KCTC 2733T was between 42.6 to 47.5%. The similarities of genome-to-genome distance between M12-1144T and related species ranged from 18.4-54.8%. Based on these results, a new species of the genus Vibrio, Vibrio injenensis is proposed. The type strain is M12-1144 T(=KCTC 32233T =JCM 30011T).
Keywords: Human clinical specimens; Polyphasic taxonomy; Vibrio injenensis sp. nov.