Streptococcus pyogenes can be checked by which drug disk: (A) Bacitracin, (B) Polymycin, (C) Optochin, (D) None of the above
Answer is A. Ans. (a) BacitracinRef.: Microbiology by Ananthanarayan and Paniker 8th ed. /201, 206-07, 2012* The various species of Streptococcus can be checked by various drug disks which is indicated as whether it is sensitive or resistant to the drug.* S. pyogenes is bacitracin sensitive.* S. agalactiae is bacitracin resistant.* S. pneumoniae is inhibited by optochin.* S. viridans is not inhibited by optochin.