Which of the following is not mechanism for resistance to MRSA -
Option 1, 2 3 mechanisms for which staphylococcus aureus become resistant to methicillin: i) Presence of an acquired penicillin binding protein (PBP2a) ii) Modification of normal (Intrinsic) penicillin binding proteins MRSA is mediated by mecA gene; which is chromosomally coded. iii) Hyperproduction of b-lactamase - Rare Option 3 MRSA resistance is not absolutely b-lactamase independent. Resistance may also be produced by hyperproduction of beta-lactamase. Option 4 Intrinsic Resistance: It is the innate ability of a bacterium to resist a class of antibiotics. S. aureus doesn't show any intrinsic resistance. Enterococci show intrinsic resistance to cephalosporins and cotrimoxazole.
Resistance is chromosomally mediated
Produced mainly by alteration in PBPs
MRSA resistance is absolutely beta-lactamase independent
Intrinsic resistance is absent
Systemic Bacteriology Pa 1 (Gram Positive Cocci, Gram Negative Cocci)