Which of the following antibiotic has a bacteriostatic effect on microbes

Chloramphenicol

The correct answer is Option (2) → Chloramphenicol.

Bacteriostatic antibiotics inhibit the growth and reproduction of bacteria without killing them directly. They work by interfering with processes like protein synthesis, which prevents the bacteria from growing and multiplying.

Chloramphenicol is a bacteriostatic antibiotic. It inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, preventing peptide bond formation.

Let us review the other options:

Penicillin: Penicillin is a bactericidal antibiotic, meaning it kills bacteria. It works by inhibiting the synthesis of bacterial cell walls.

Aminoglycosides: Aminoglycosides (e.g., gentamicin) are bactericidal antibiotics. They cause misreading of mRNA, leading to bacterial cell death.

Ofloxacin: Ofloxacin is a bactericidal antibiotic. It belongs to the fluoroquinolone class and kills bacteria by inhibiting DNA gyrase and topoisomerase IV, which are essential for bacterial DNA replication.

Thus, Chloramphenicol is the antibiotic with a bacteriostatic effect.