Multiple Drug-Resistant Staphylococcus aureus (MRSA) is a bacterium that has developed resistance to a wide range of antibiotics
Its resistance to penicillin, methicilliin, and oxacillin is a result of the serial use of these antibi-otics, which created a selective environment that favored resistance to the drug being used at the time. This resistance provides this class of bacteria the ability to thrive while being treated with standard antibiotics, thereby making it a dangerous human health hazard. Why would one expect MRSA to retain penicillin resistance even if this antibiotic is rarely used?
What will be an ideal response?
ANS:
The MRSA strain has experienced several rounds of periodic selection, which has gen-erated a single nonrecombining chromosome conveying resistance to multiple drugs. In the absence of sexual reproduction and recombination, these alleles are unlikely to be disrupted.
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What will be an ideal response?
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