Phylogenetic Analysis of Four Vibrio Strains of Pathogenic Bacteria Based on Hemolysin Genes and 16S rRNA Genes

Abstract

In order to understand the phylogenetic relationships among Vibrio species more rationally , the hemolysin gene partial sequences of 4 Vibrio species ( Vibrio alginolyticus, Vibrio harveyi, Vibrio parahaemolyticus, Vibrio minius ) were amplifyed and sequenced. We constructed two separate phylogenetic trees by using 16S rRNA and partial hemolysin gene sequences, respectively.The average similarities of hemolysin gene of Vibrio species was 37.2%. Meanwhile, the average similarity of 16S rRNA gene of Vibrio species was 91.4%. The variabilities of hemolysin gene in vibrio is greater than that of 16S rRNA gene. By comparing the phylogenetic trees, the topology of hemolysin gene tree is almost consistent with that of 16S rRNA gene tree. Consequently, the hemolysin gene possesses the superiority in phylogenetic taxonomy of the genus Vibrio . Taxonomic classification of Vibrios with hemolysin gene instead of 16S rRNA gene was proved a better approach.