A farmer presents with pustules showing gram-positive cocci, beta hemolysis, catalase negative. To show it is group A streptococci, which of the following test is done
Streptococcus pyogenes or Group A streptococcus is gram-positive, beta Hemolytic and catalase negative. A convenient method for the identification of Streptococcus pyogenes is based on Maxted's observation that they are more sensitive to bacitracin than other Streptococci. Bacitracin sensitivity test: A filter paper disc of 0.04U is applied on the surface of an inoculated blood agar. After incubation, a wide zone of inhibition is seen with Streptococcus pyogenes and not with other streptococci. Reference: Textbook of Microbiology; Anathanarayan and paniker's; 10th edition; Page no: 217
Bacitracin
Optochin
Novobiocin
Bile solubility
Bacteriology