Final answer:
Penicillinase-resistant penicillins, like Methicillin, Nafcillin, and Oxacillin, are effective against gram-positive bacteria, including MRSA. However, their effectiveness against other types of bacteria is limited.
Step-by-step explanation:
Penicillinase-resistant penicillins, also known as anti-staph penicillins, are a group of antibiotics that are effective against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). These antibiotics, such as Methicillin, Nafcillin, and Oxacillin, are designed to resist inactivation by penicillinase enzymes produced by certain bacteria.
Methicillin, in particular, was developed to address the spread of penicillinase enzymes that were inactivating other penicillins. However, MRSA strains have emerged that are resistant to methicillin. These resistant strains can cause a variety of infections, including skin and wound infections, pneumonia, and septicemia.
Overall, penicillinase-resistant penicillins have a spectrum of activity that includes gram-positive bacteria, but their effectiveness against other types of bacteria, such as gram-negative bacteria, is limited.