This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
[{'content': 'True about methicillin-resistance Staphylococcus aureus (MRSA) is \nSelect and explain. \nA. Isoxazolyl penicillin is highly effective, B. All MRSA are multidrug resistance, C. Vancomyin is effective, D. MRSA are more virulent then sensitive strains', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Penicillin resistance may also be due to alterations in penicillin-binding protein PBP2a and changes in bacterial surface receptors, reducing the binding affinity 0f beta-lactam antibiotics to cells. This mechanism impas resistance to all beta-lactam antibiotics and has been named methicillin-resistant S.aureus{MRSA}as it was found to be resistant to penicillinase-resistant penicillins like methicillin and cloxacillin. The majority of these strains also show resistance to other antibiotics like erythromycin, tetracyclines, aminoglycosides and cause outbreaks of hospital infection. Ref: Textbook of Microbiology; Ananthanarayanan and Panicker; Tenth Edition pg no 202', 'role': 'assistant'}]