Induction of Differentiation of Vibrio parahaemolyticus into Swarmer Cells

Begin with a molten agar medium that supports bacterial growth.

Add an iron chelator to deplete free iron, and supplement the medium with calcium.

Pour the medium into a dish, allow it to solidify, and then dry it to eliminate residual moisture.

Take a broth culture of Vibrio parahaemolyticus, a flagellated bacterium.

In liquid media, the bacteria exist in a short, rod-shaped swimmer form with a flagellum.

Spot the culture onto the plate and allow it to dry to promote bacterial contact with the surface.

Seal the dish and incubate, allowing volatile metabolic by-products from the bacteria to accumulate.

Surface contact, iron limitation, calcium availability, and accumulated by-products induce gene expression, which triggers the differentiation into elongated swarmer cells containing lateral flagella, enabling movement across solid surfaces.

The swarmer cells expand outward and form swarm flares composed of fully differentiated cells, indicating successful differentiation.

To prepare the agar solution for making swarming plates, suspend four grams of heart infusion, or H. I. agar powder, and 100 milliliters of double-distilled water.

Carefully boil the H. I. agar solution in a microwave oven,