Preparation of a Murine Oropharyngeal Aspiration Model to Establish Bacterial Lung Infections

Begin with a secured anesthetized mouse. Gently pull its tongue to expose the oropharynx, the region of the throat located behind the mouth.

Deliver a small volume of bacterial suspension into the oropharynx.

The liquid remains in the oropharynx and triggers a breathing reflex.

This reflex causes oropharyngeal aspiration, pulling the bacteria down the trachea into the lungs.

The bacteria reach the small airways and alveoli, where they multiply and attach to the epithelial lining of the lung tissue.

This activates resident macrophages and leads to the release of signaling molecules that recruit neutrophils. These neutrophils release cytokines, leading to inflammation.

Return the mouse to its cage and monitor it.

After the mouse has been euthanized, cut the trachea and nearby blood vessels to remove the lungs.

Embed the lungs in tissue-freezing medium and freeze them for further analysis of bacteria-infected lung tissue.

To inoculate the mice, hang the first anesthetized animal by its top incisors on a strong, thin string. Secure it to a fixed object above the operating surface, at a height approximately twice the mouse's body length. Use sterile blunt-ended forceps to gently pull out the ton