Cloning, characterisation and expression of Aeromonas hydrophila major adhesin.
Aeromonas hydrophila, an important pathogen in fish, is believed to cause diseases by adhesive and enterotoxic mechanisms. The adhesion is a prerequisite for successful invasion. In this study, the gene of a 43 kDa major adhesin (designated as AHA1) was cloned and expressed. Nucleotide sequence analysis of AHA1 revealed an open reading frame encoding a polypeptide of 373 amino acids with a 20-amino-acid putative signal peptide (molecular weight 40,737 Da). The amino acid sequences of Aha1p showed a very high homology with the other two outer membrane proteins of A. hydrophila. Using the T-5 expression system, this major adhesin Aha1p was expressed in Escherichia coli. The purified recombinant adhesin could competitively inhibit A. hydrophila from invading fish epithelial cells in vitro. Western-blot analysis showed that this major adhesin is a very conserved antigen among various strains of Aeromonas. When used to immunise blue gourami, the recombinant adhesin could confer significant protection to fish against experimental A. hydrophila challenge.
Fang
Hao-Ming
HM
Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Road, 119206, Singapore.
Ge
Ruowen
R
Sin
Yoke Min
YM
D018829:Adhesins, Bacterial / Q000235:genetics* / Q000378:metabolism; D016980:Aeromonas hydrophila / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D004847:Epithelial Cells / Q000378:metabolism; D004926:Escherichia coli; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control*; D015870:Gene Expression; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010473:Perciformes; D010957:Plasmids / Q000235:genetics; D021382:Protein Sorting Signals / Q000235:genetics; D011994:Recombinant Proteins / Q000276:immunology* / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014611:Vaccination / Q000662:veterinary*
D018829:Adhesins, Bacterial; D017931:DNA Primers; D021382:Protein Sorting Signals; D011994:Recombinant Proteins