Final answer:
Malignant (Necrotizing) Otitis externa is commonly caused by the bacterium Pseudomonas aeruginosa. Treatment usually involves ear drops containing acetic acid, antibacterials, steroids, and sometimes antifungals. Polymyxin B, gentamicin, and fluoroquinolones are effective against Pseudomonas spp.
Step-by-step explanation:
The causative organism of malignant (necrotizing) otitis externa is Pseudomonas aeruginosa. It is an infection of the external ear canal that can be caused by the bacterium. It is commonly referred to as swimmer's ear. The treatment for malignant otitis externa usually involves ear drops containing acetic acid, antibacterials, steroids, and sometimes antifungals. Polymyxin B, gentamicin, and fluoroquinolones are effective antibiotics against Pseudomonas spp.