Streptococcus pyogenes is a type of bacteria that belongs to the group of bacteria known as streptococci. It is a gram-positive bacterium, meaning it has a thick cell wall that retains a purple stain during laboratory testing. This bacterium is known for causing a variety of infections, including strep throat, skin infections, and more serious conditions like rheumatic fever and necrotizing fasciitis. Streptococcus pyogenes is typically spread through respiratory droplets or direct contact with infected wounds. Symptoms of infections can vary depending on the type, but common signs include sore throat, fever, and redness or swelling in affected areas. Treatment usually involves antibiotics, which are effective in eliminating the bacteria and preventing complications.