Final answer:
Methicillin-resistant Staphylococcus aureus (MRSA) is resistant to all penicillinase-resistant penicillins and all β-lactam agents due to the acquisition of a new low-affinity penicillin-binding protein. Treatment often requires alternative medications. The correct answer to the given question is 'd. all penicillinase-resistant penicillins as well as all β-lactam agents'.
Step-by-step explanation:
Methicillin-resistant Staphylococcus aureus (MRSA) is a significant public health concern because of its resistance to numerous antibiotics. Methicillin was one of the first antibiotics that MRSA became resistant to, alongside other beta-lactam antibiotics, such as oxacillin, amoxicillin, and penicillin. The resistance is due to the acquisition of a new low-affinity penicillin-binding protein (PBP), which renders the bacteria insensitive to all available β-lactam agents.
MRSA infections can occur both in health-care settings (hospital-acquired MRSA or HA-MRSA) and in the community (community-associated MRSA or CA-MRSA). These bacteria can cause a variety of infections, including skin and wound infections, pneumonia, and septicemia. They present a therapeutic challenge as the treatment options for MRSA infections are limited due to its resistance to a wide spectrum of antibiotics, necessitating the use of alternative medications such as trimethoprim-sulfamethoxazole (TMP/SMZ), clindamycin, tetracyclines, or linezolid in some cases.
Therefore, the correct answer to the question is d. all penicillinase-resistant penicillins as well as all β-lactam agents. This reflects the broad antibiotic resistance characteristic of MRSA strains.