Which class of microorganisms is responsible for causing strep throat?

The correct answer is bacteria, specifically a type known as Streptococcus pyogenes, which is the primary causative agent of strep throat. This microorganism is a gram-positive bacterium that can infect the throat and tonsils, leading to inflammation, pain, and other classic symptoms of strep throat.

Strep throat is characterized typically by a sore throat, fever, and swollen lymph nodes, and the diagnosis is often confirmed through throat culture or rapid antigen testing. While viruses can also cause similar symptoms, they are not the specific organisms involved in strep throat. Fungi and parasites do not play a role in this particular throat infection, as they typically cause different types of infections or diseases that are unrelated to bacterial throat infections. Understanding the specific role of bacteria in diseases like strep throat is crucial for proper diagnosis and treatment.