Immunization with bacterial antigens: Vibrio infections

Area of Science:

• Aquatic animal health
• Bacteriology
• Fish immunology and vaccination

Background:

• Economically significant marine fish diseases are caused by Vibrio species, including Vibrio anguillarum, V. ordalii, V. salmonicida, and V. vulnificus biotype 2.
• Vibrio anguillarum serotypes O1, O2, and O3 are implicated in widespread fish mortality, with O1 being homogeneous and O2/O3 exhibiting genetic heterogeneity.
• Current commercial vaccines often lack comprehensive coverage, particularly for Vibrio anguillarum O2 subgroups and newly identified Vibrio anguillarum-related (VAR) strains.

Purpose of the Study:

• To review host range, clinical importance, and virulence mechanisms of key Vibrio fish pathogens.
• To analyze antigenic variants, genetic diversity, and vaccine efficacy for Vibrio anguillarum and related species.
• To discuss the necessity of including novel VAR strains in future vibriosis vaccines.

Main Methods:

• Literature review and synthesis of existing data on Vibrio species.
• Analysis of serological, biochemical, and genetic characteristics of Vibrio anguillarum and VAR strains.
• Evaluation of current vaccine formulations and their limitations.

Main Results:

• Vibrio anguillarum serotypes O1, O2, and O3 are the primary causes of vibriosis in farmed and feral fish.
• Significant genetic and antigenic diversity exists within V. anguillarum serotypes O2 and O3.
• VAR strains, distributed into at least seven O-serogroups, represent a potential threat not adequately addressed by current vaccines.

Conclusions:

• Existing Vibrio vaccines, often based on V. anguillarum O1 and V. ordalii, may not provide sufficient protection against diverse Vibrio strains.
• The genetic heterogeneity of V. anguillarum O2 and O3, along with the emergence of VAR strains, necessitates vaccine 업데이트.
• Future vaccine development should consider incorporating representative VAR strains to broaden protection against economically important fish diseases.