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What is Gene responsible for semisynthetic penicillin resistance in Methicillin resistant Staph aureus (MRSA)? and explain in detail?
Methicillin resistance in S. aureus is mediated by a chromosomally coded gene called mec A gene, which alters penicillin-binding protein (PBP) present on S. aureus cell membranetoPBP-2a. * PBP is an essential protein needed for cell wall synthesis of bacteria. Beta lactam drugs bind and inhibit this protein, thereby inhibit the cell wall synthesis. * The altered PBP2a of MRSA strains has less affinity for beta lactam antibiotics; hence, MRSA strains are resistant to all beta lactam antibiotics.