<prompt> A diabetic patient developed cellulitis due to staphylococcus aureus, which was found to be Methicillin resistant on the antibiotic sensitivity testing. All the following antibiotics will be appropriate except-VancomycinImipenemTeichoplaninLinezolid  <response>: Ans. is b i.e., Imipenem The carbapenem imipenem has excellent activity against methicillin-sensitive S.aureus but not MRSA. MRSA is resistant to all beta-lactam antibiotics because resistance develops due to alteration in transpeptidase penicillin binding protein on which all beta-lactam antibiotics act. Drugs for MRSA -- Vancomycin DOC, Ciprofloxacin Quinopristindalfopristin Tigecyclin TMP-SMX Linezolid Daptomycin Teicoplanin Minocyclin Levofloxacin Oritavaccin Cotrimoxazole 