Bacteria cause strep throatViruses are the most common cause of a sore throat. However, strep throat is an infection in the throat and tonsils caused by bacteria called group A Streptococcus (group A strep). How you get strep throatGroup A strep live in the nose and throat and can easily spread to other people. People who are infected spread the bacteria by talking, coughing, or sneezing, which creates small respiratory droplets that contain the bacteria. They can also spread the bacteria from infected sores on their skin. It usually takes two to five days for someone exposed to group A strep …