Question

Why did methicillin resistance lag behind penicillin resistance

Answer 1

The methicillin-resistant form of the bacterium commonly known as staph was first identified in the 1970's in hospitals, but it has since spread across the world, showing up in day cares, schools and other public spaces. Today, 1.2 million MRSA infections occur in hospitals in the U.S. and invasive MRSA kills over 19,000 per year,However, In the past, penicillin was used to treat Staphylococcus aureus infections. Shortly after, S. aureus became resistant to penicillin. During the 1950s, derivatives of penicillin was discovered by pharmaceutical companies that could treat Staphylococcus aureus . The graph below depicts the Spread of Antibiotic-Resistant S. aureus Infections in the United States. Separate curves are shown for bacteria that caused infections in the hospital ("Hospital-Acquired") and in healthy people in the community ("Community-Acquired").


information found at https://www.biologycorner.com/worksheets/case_study_bacteria_resistance.html

Answer 2

Methicillin is the leader in penicillin M.

Penicillins in group M are bactericidal antibiotics of the beta lactam family. Bacteria have developed penicillinases to make these antibiotics ineffective. In contrast to penicillins in group "G" and "V", penicillins in group M are resistant to penicillinases of staphylococci. This explains the relative efficacy and the lagging of resistance against this group of penicillin compared to other groups.