A farmer presents with pustules, which show Gram Positive Cocci on smear. Culture shows Beta hemolysis, and organisms are Catalase negative. To show that the identified organism is group A streptococci, which of the following test should be done?

Streptococci are catalase negative and beta hemolytic. Group A beta hemolytic streptococci can be differentiated from other beta hemolytic streptococci by bacitracin sensitivity. Streptococcus pyogenes is bacitracin sensitive whereas streptococcus agalactiae is bacitracin resistant. Both are beta hemolytic. Ref: Textbook of Microbiology, Ananthanarayan and Paniker, 7th Edition, Chapter 23, Page 203-205.