Which antibiotic is bactericidal?

Which antibiotic is bactericidal?

• A. Chloramphenicol
• B. Erythromycin
• C. Tetracycline
• D. Tobramycin

Answer: (D)

Bactericidal drugs kill bacteria outright rather than just stopping their growth. Tobramycin, an aminoglycoside, binds irreversibly to the 30S ribosomal subunit, causing misreading of the genetic code and production of faulty proteins. This disruption leads to bacterial death, especially with higher (concentration-dependent) levels and the post-antibiotic effect. In contrast, macrolides like erythromycin and tetracyclines mainly inhibit protein synthesis and typically halt growth without directly killing the bacteria, and chloramphenicol is usually bacteriostatic as well. So tobramycin best fits the bactericidal category.

Bactericidal drugs kill bacteria outright rather than just stopping their growth. Tobramycin, an aminoglycoside, binds irreversibly to the 30S ribosomal subunit, causing misreading of the genetic code and production of faulty proteins. This disruption leads to bacterial death, especially with higher (concentration-dependent) levels and the post-antibiotic effect. In contrast, macrolides like erythromycin and tetracyclines mainly inhibit protein synthesis and typically halt growth without directly killing the bacteria, and chloramphenicol is usually bacteriostatic as well. So tobramycin best fits the bactericidal category.