Which of the following is bactericidal antibiotics?

Question

Accepted Answer

Ofloxacin is the correct answer as a bactericidal antibiotic. Here's a detailed explanation supporting this choice and why the other options are incorrect:

1. **Ofloxacin (Option 2)**: Ofloxacin is a fluoroquinolone antibiotic that is known for its bactericidal properties. It works by inhibiting bacterial DNA gyrase and topoisomerase IV, enzymes critical for DNA replication and transcription. By disrupting these processes, Ofloxacin effectively kills the bacteria, making it a bactericidal agent. This mechanism of action is why Ofloxacin is classified as a bactericidal antibiotic, which directly leads to bacterial cell death.

2. **Erythromycin (Option 1)**: Erythromycin is a macrolide antibiotic that is primarily bacteriostatic rather than bactericidal. It works by binding to the 50S ribosomal subunit of bacteria, inhibiting protein synthesis. This action prevents bacteria from growing and reproducing but does not directly kill them, which is why it is considered bacteriostatic.

3. **Tetracycline (Option 3)**: Tetracycline is another example of a bacteriostatic antibiotic. It inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, preventing the addition of amino acids to the growing peptide chain. Like Erythromycin, Tetracycline stops bacterial growth and reproduction but does not kill the bacteria outright, classifying it as bacteriostatic.

4. **Chloramphenicol (Option 4)**: Chloramphenicol is also primarily bacteriostatic. It inhibits protein synthesis by binding to the 50S ribosomal subunit, similar to Erythromycin. While it can be bactericidal against certain organisms in high concentrations or specific conditions, it is generally considered bacteriostatic in its typical use.

In summary, Ofloxacin is the correct answer because it is a bactericidal antibiotic that kills bacteria by interfering with their DNA replication processes. The other options, Erythromycin, Tetracycline, and Chloramphenicol, are primarily bacteriostatic, inhibiting bacterial growth rather than directly causing bacterial cell death.