Oral Infection of Drosophila melanogaster with Pathogenic Bacteria

Take a vial with a lid that holds nutrient agar overlaid with filter paper.

Apply a suspension of pathogenic bacteria onto the filter paper.

Introduce a starved Drosophila melanogaster fly into the vial, then place the lid. Incubate to allow feeding and ensure bacterial ingestion.

The ingested bacteria enter the gut and penetrate the protective membrane lining the lumen.

The bacteria adhere to the underlying epithelium, release toxins that promote epithelial damage and invasion, and colonize internal tissues.

Immerse the fly in alcohol to remove surface-associated bacteria, then rinse to remove alcohol.

Add a buffer and homogenize the fly to release the internal bacterial contents.

Perform serial dilutions of the homogenate in a microplate. Next, plate the dilutions onto nutrient agar and incubate to allow colony formation.

Count the colonies to determine the number of viable bacterial cells resulting from oral infection in the fly.

Two to four hours before the oral infection, transfer the flies to standard agar vials containing no food. Meanwhile, for each fly, prepare an infection vial.

First, load the lid of a 7 milliliter sample tube with 500 microliters of standard sugar agar and let it