Aeromonas flagella and colonisation mechanisms

Area of Science:

• Microbiology
• Pathogen Biology
• Aquatic Microbiology

Background:

• Aeromonas species are aquatic bacteria causing diseases in fish (e.g., furunculosis, motile Aeromonas septicaemia) and humans (e.g., gastroenteritis, wound infections).
• These bacteria possess diverse colonization factors enabling survival in various environments and infection of hosts.

Purpose of the Study:

• To review the colonization factors employed by Aeromonas species.
• To understand the mechanisms underlying Aeromonas-associated diseases in aquaculture and human health.

Main Methods:

• Literature review of studies on Aeromonas virulence and colonization factors.
• Analysis of flagellar systems (polar and lateral), fimbriae, outer-membrane proteins, and surface structures (S-layers, capsules, LPS).

Main Results:

• Motile Aeromonas species utilize polar flagella for swimming and lateral flagella for swarming on surfaces, both critical for initial colonization.
• Non-flagellar factors include MSHA type IV pili for human cell adherence and outer-membrane proteins involved in adhesion.
• Some strains exhibit cell invasion capabilities, linked to invasive diseases, employing surface factors for immune system evasion.

Conclusions:

• Aeromonas colonization is multifactorial, involving flagella, pili, outer-membrane proteins, and surface structures.
• Understanding these factors is key to controlling Aeromonas-related diseases in aquaculture and human medicine.