An isolate of Klebsiella pneumoniae from a ventilator-associated pneumonia is reported as resistant to gentamicin, tobramycin, and netilmicin on sensitivity testing. Which aminoglycoside is most likely to retain activity against this isolate?
- A Streptomycin
- B Framycetin
- C Neomycin
- D Amikacin ✓
Explanation
Amikacin has the broadest Gram-negative spectrum among aminoglycosides because its structure, with an L-hydroxyaminobutyric acid side chain, makes it a poor substrate for most aminoglycoside-modifying enzymes. Organisms resistant to gentamicin and tobramycin through enzymatic modification frequently remain amikacin-susceptible, making it the preferred agent for nosocomial infections caused by resistant Gram-negative bacilli. Streptomycin has a narrow spectrum, and neomycin and framycetin are too toxic for systemic use and are limited to topical or bowel preparation roles.
Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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