<prompt> How to differentiate staphylococci and micrococciCatalase testHugh and Leifsons oxidation-fermentation testGram stainingAFS  <response>: Micrococci are gram-positive cocci which can be mistaken for S.aureus in culture but are larger and mostly in pairs, tetrads or irregular clusters. Micrococci is catalase and modified oxidase positive and oxidative in Hugh and Leifsons oxidation-fermentation test. Ref: Textbook of Ananthanarayan and panikers; 10th Edition; Pg:209 