Elastolytic activity among Aeromonas spp. Using a modified bilayer plate assay.

Area of Science:

• Microbiology
• Enzymology
• Bacteriology

Background:

• Aeromonas species are increasingly recognized as significant opportunistic pathogens.
• Elastase production is a potential virulence factor in Aeromonas infections.
• Accurate identification and characterization of Aeromonas strains are crucial for clinical and epidemiological studies.

Purpose of the Study:

• To evaluate the elastase-producing capability of diverse Aeromonas isolates using a bilayer elastin agar medium (BEAM) plate assay.
• To determine the correlation between elastase production and specific Aeromonas species.
• To assess the utility of elastase detection as a phenotypic marker for clinically important Aeromonas species.

Main Methods:

• A total of 166 Aeromonas isolates from various sources were cultured on BEAM plates.
• Elastase activity was quantified by measuring the clear zone around colonies (1+, 2+, or 3+).
• Species identification and elastase production were analyzed for each isolate.

Main Results:

• Out of 166 isolates, 53 (32%) exhibited elastase activity.
• Aeromonas hydrophila showed the highest prevalence of elastase production (98%), with all strong (3+) activity attributed to this species.
• Elastase activity was not detected in Aeromonas veronii biogroup sobria, A. caviae, A. veronii biogroup veronii, A. media, or A. eucrenophila.

Conclusions:

• The BEAM plate assay is a reliable method for detecting elastase production in Aeromonas.
• Elastase production, particularly strong activity, is a characteristic primarily associated with Aeromonas hydrophila.
• Elastase detection serves as a useful phenotypic marker for identifying major, clinically relevant Aeromonas species.