<prompt> A child presents with infective skin lesion of the leg. Gram stain from the specimen shows pus cells with gramve cocci in chains and culture is done which shows hemolytic colonies. The test to confirm the organism is -Bile solubilityOptochin sensitivityBacitracin sensitivityCatalase positive  <response>: Infective skin lesion with gram positive cocci in chains and hemolytic colonies suggest infection of Streptococcus pyogenes. Option 1, 2 Pneumococcus: Bile solubility Positive Bile soluble Optochin sensitivity Option 3 Streptococcus Pyogenes Transpo medium: Pikes medium Direct smear microscopy: Pus cells with gram-positive cocci in sho chains Culture: Blood agar: Pinpoint colony with a wide zone of b-hemolysis Selective media: Crystal violet blood agar and PNF polymyxin B, neomycin, fusidic acid media Liquid media: Granular turbidity with powdery deposit Biochemical: Catalase negative, Bacitracin sensitive Maxteds observation Pyrrolidonyl Arylamidase PYR test is positive. Option 4 Catalase ve: Staphylococcus spp. Catalase -ve: Streptococcus spp. 