PHARMACOLOGY - Penicillin Resistance Mechanism Vol 4 | NEET PG 2024 PYQ

🎧 High-Yield Daily Clinical Revision Podcast for NEET PG, FMGE, and INI-CET! 📖 Clinical Case Study: [Challenge Vol 4] A strain of Staphylococcus aureus isolated from a wound culture is resistant to penicillin G but sensitive to methicillin. What is the mechanism of resistance of this strain? 📝 Options: • Option A: A. Production of beta-lactamase (penicillinase) • Option B: B. Alteration of Penicillin-Binding Protein (PBP2a) • Option C: C. Mutational change in porin channels • Option D: D. Upregulation of active drug efflux pumps ✅ Correct Answer: Option A 💡 Explanation: Standard penicillin resistance in S. aureus is mediated by the production of plasmid-encoded beta-lactamase (penicillinase) which hydrolyzes the beta-lactam ring. Methicillin-resistant S. aureus (MRSA), however, is mediated by altered PBPs (PBP2a encoded by the mecA gene). (Volume 4 High-Yield Concept Review) 🧠 Mnemonic: Penicillin vs Methicillin Resistance V4 • Penicillin Resistance ➔ Beta-lactamase production (hydrolyzes G/V) • Methicillin Resistance (MRSA) ➔ PBP alteration (mecA gene PBP2a) • Treatment for MRSA ➔ Vancomycin ⚠️ Exam Trap to Avoid: Do not confuse beta-lactamase production (standard resistance) with altered PBPs (MRSA/mecA resistance). 🔗 Follow Us & Prepare Smart: • 📸 Instagram: instagram.com/drstemcell_1 • 🧵 Threads: threads.net/@drstemcell_1 • 📺 YouTube: youtube.com/@drstemcell-o2h • 👥 Facebook: facebook.com/drstemcell • 🍎 Apple Podcasts: Apple Podcasts Link 🏆 Join the discussion! Did you get this correct? Drop your option or score in the comments below! 👇 #NEETPG #FMGE #INICET #MBBS #DrStemCell #MedEd