Molecular identification and codon optimization analysis of major virulence encoding genes of Aeromonas hydrophila

Abstract

Aeromonas hydrophila is an opportunistic pathogen of aquatic and terrestrial animals and human beings. The aim of this study is to investigate 25 isolates of A. hydrophila from 40 fish muscles and 12 water samples. All isolates are screened for the presence of virulence factors such as aerolysin, hemolysin and lipase both phenotypically as well as genotypically. All the isolates produced lipase, whereas only 60% of isolates produced β-hemolysis with RBCs. The presence of 3 virulence genes aerolysin, hemolysin and lipase were confirmed by PCR assay, which gave positive PCR amplification for conserved fragment. These were also codon optimized for over expression in Escherichia coli and obtained the high codon adaptation index in comparison to wild type of DNA sequences. These finding may help to better expression of gene for scale up production of vaccine candidates.