Strep throat is caused by a certain strain of bacteria called beta-hemolytic, Group A Streptococcus pyogenes, which are normal inhabitants of our mouths and throat. However, when the environment in our mouths and throats changes due to viral infections, stress, or other medical conditions these strep bacteria increase. The actual sore throat or pharyngitis is due to proteins produced by the bacteria that damage local cells and cause the host to respond with an inflammatory response.3 __
