Final answer:
Strep throat, a common cause of pharyngitis, is primarily caused by Streptococcus pyogenes. It can be easily spread through direct contact or droplet transmission and is diagnosed using rapid enzyme immunoassays or culture identification.
Step-by-step explanation:
The most common cause of pharyngitis, particularly strep throat, is Streptococcus pyogenes. This bacterium belongs to the Lancefield group A and is a pyogenic pathogen. It can easily spread through direct contact or droplet transmission and is diagnosed using a rapid enzyme immunoassay or culture identification. Treatment usually involves antibiotics like oral amoxicillin or intramuscular penicillin G.