Which pathogen is commonly treated with antibiotics?

Bacteria are commonly treated with antibiotics because antibiotics are specifically designed to target the cellular mechanisms of bacteria. These medications can inhibit bacterial growth or kill bacteria by interfering with their ability to reproduce or synthesize their cell walls, which is crucial for their survival. This is why bacterial infections, such as strep throat or urinary tract infections, are often effectively treated with antibiotics.

In contrast, viruses are not affected by antibiotics because they have a different structure and reproduction method. Treatments for viral infections instead focus on antiviral medications. Protozoa, which are single-celled organisms, can require different forms of treatment, such as antiprotozoal medications, and fungi are treated with antifungal drugs. Therefore, among the options provided, bacteria are the only pathogens commonly treated with antibiotics.