Aeromonas sharmana sp. nov., isolated from a warm spring.

A Gram-negative, facultatively anaerobic bacterial strain designated GPTSA-6(T) was isolated from a water sample collected from a warm spring in Assam, India. Preliminary analysis of the 16S rRNA gene sequence of this isolate revealed its affiliation to the family Aeromonadaceae. Detailed characterization using a polyphasic approach indicated that strain GPTSA-6(T) is most closely related to Aeromonas sobria but differs significantly from existing members of the genus Aeromonas. Analysis of the almost-complete (1430 nt) 16S rRNA gene sequence of this strain revealed that its closest relative (99.23 % similarity) is an uncultured bacterial clone, A-8, isolated from an algal bloom. Of the taxa with validly published names, Aeromonas sobria ATCC 43979(T) showed the highest level of sequence similarity (95.13 %) with respect to strain GPTSA-6(T), followed by Aeromonas molluscorum 848T(T) and Aeromonas popoffii LMG 17541(T) (95.04 % similarity in both cases). On the basis of the phenotypic, chemotaxonomic and phylogenetic data, it can be concluded that strain GPTSA-6(T) represents a novel species of the genus Aeromonas, for which the name Aeromonas sharmana sp. nov. is proposed. The type strain is GPTSA-6(T) (=MTCC 7090(T)=DSM 17445(T)).