Species-specific Identification of Vibrio sp. based on 16S-23S rRNA gene internal transcribed spacer.

Abstract

To explore a prokaryotic species-specific DNA marker, 16S-23S rRNA gene internal transcribed spacer (ITS) sequence for identification and classification of Vibrio. Five hundred and seventy four ITS sequences from 60 Vibrio strains were collected, then the primary and secondary structures of ITS sequence were analysed. The ITS was divided into several subunits, and the species-specificity of these subunits were evaluated by blast. The variable subunit of ITS showed high species-specificity. A protocol to identify a Vibrio species based on ITS analysis was developed and verified. Both the specificity and sensitivity were 100%. The phylogeny analysis of Vibrio based on ITS showed that ITS devised a better classification than 16S rDNA. Finally, an identification method of Vibrio based on ITS sequencing in food samples was developed and evaluated. The results of ITS sequencing were (100%) consistent with the results identified by ISO standard. Vibrio could be accurately identified at the species level by using the ITS sequences. The present study suggests that the ITS can be considered as a significant DNA marker for identification and classification of Vibrio species, and it posed a new path to screen the Vibrio in food sample.