Ans. B. Staphylococcus aureusBacterial tracheitis is an uncommon infectious cause of acute upper airway obstruction. Patients may present with croup like symptoms, such as barking cough, stridor, and fever; however, patients with bacterial tracheitis do not respond to standard croup therapy (racemic epinephrine) and instead require treatment with antibiotics and may experience acute respiratory decompensation. Bacterial tracheitis is a diffuse inflammatory process of the larynx, trachea, and bronchi with adherent or semi adherent mucopurulent membranes within the trachea. Acute airway obstruction may develop secondary to subglottic edema and sloughing of epithelial lining or accumulation of mucopurulent membrane within the trachea. The responsible pathogen is Staphylococcus aureus.