what causes bacterial throat infections?
Bacterial throat infections. Bacteria and viruses are the main causes of a throat infection although they can be caused by other factors such as an allergy, oral thrush, a symptom of another condition or overuse of the voice. This section looks at bacterial throat infections.
Strep Throat Causes. Strep throat is caused by infection with Group A Streptococcus (GAS) bacteria, specifically Streptococcus pyogenes. The streptococcal infection invades the pharyngeal tissue and causes a localized inflammatory reaction of the throat and tonsils.