Question

How do MRSA bacteria specifically exhibit resistance to antibiotics? They produce b-lactamase, an enzyme that destroys penicillins They evade the antibiotic molecules by evading binding with antibodies They produce methicillin, which inactivates penicillin They produce endotoxin, which inactivates antibodies

Answer 1

Answer:

They produce b-lactamase, an enzyme that destroys penicillins

They evade the antibiotic molecules by evading binding with antibodies

Explanation:

MRSA bacteria is resistant to a class of penicillin like antibiotics called beta-lactams. Beta-lactams includes penicillin, methicillin, oxacillin, amoxicillin etc. These antibiotics have a common structural molecular component, a four atom beta-lactam ring. MRSA bacteria like Staphylococcus aureus produces beta-lactamase which destroys the beta-lactam ring hence destroying the antibiotic structure. It opens up the ring structure by hydrolysis which inactivates the antibacterial properties of antibiotic.

Another strategy by MRSA bacteria is to evade binding with antibiotics. Staphylococcus aureus have evolved with a novel antibiotic binding site called as PBP ( Penicillin Binding Site ) 2'. PBP2' has lower affinity for antibiotics so the bacteria can infect even in the presence of inhibitory concentration of antibiotic.

Answer 2

Answer:the expression of an enzyme (the PC1 β-lactamase) capable of hydrolyzing the β-lactam ring and the acquisition of a gene encoding a modified penicillin-binding protein

Explanation:

Staphylococci have two primary mechanisms for resistance to β-lactam antibiotics: the expression of an enzyme (the PC1 β-lactamase) capable of hydrolyzing the β-lactam ring, thus rendering the antibiotic inactive, and the acquisition of a gene encoding a modified penicillin-binding protein (PBP), known as PBP 2a, found in MRSA and coagulase-negative staphylococci. PBP 2a is intrinsically resistant to inhibition by β-lactams