A patient with hospital-acquired pneumonia is prescribed a new antibiotic that inhibits bacterial isoleucyl-tRNA synthetase, preventing aminoacyl-tRNA formation and thus protein synthesis. This drug is:
- A Retapamulin
- B Omadacycline
- C Ceftaroline
- D Mupirocin (pseudomonic acid) ✓
Explanation
Mupirocin (pseudomonic acid A) uniquely inhibits bacterial isoleucyl-tRNA synthetase (IleRS), preventing incorporation of isoleucine into growing peptide chains and halting protein synthesis. This mechanism is distinct from ribosome-binding antibiotics. Mupirocin is primarily used topically (intranasal MRSA decolonisation, skin infections). Retapamulin is a pleuromutilin that binds the 50S ribosomal subunit at a unique site. Omadacycline is a next-generation aminomethylcycline tetracycline. Ceftaroline is a fifth-generation cephalosporin active against MRSA via PBP2a binding.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.