The correct answer is option 3. Penicillin.
Let us look into the details of each antibiotic mentioned and discuss their spectrum of activity:
1. Ofloxacin: Ofloxacin belongs to the fluoroquinolone class of antibiotics. It exhibits a broad spectrum of activity, meaning it is effective against both Gram-positive and Gram-negative bacteria. It works by inhibiting bacterial DNA gyrase and topoisomerase IV enzymes, which are essential for DNA replication and repair in bacteria. Ofloxacin is commonly used to treat a variety of bacterial infections, including urinary tract infections, respiratory tract infections, skin infections, and sexually transmitted infections.
2. Vancomycin: Vancomycin is a glycopeptide antibiotic that primarily targets Gram-positive bacteria. It is particularly effective against multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Vancomycin works by inhibiting cell wall synthesis in bacteria, leading to cell lysis and death. While it is not effective against Gram-negative bacteria due to its inability to penetrate their outer membrane, it is considered a broad-spectrum antibiotic within the context of Gram-positive infections.
3. Penicillin: Penicillin is a beta-lactam antibiotic that primarily targets Gram-positive bacteria. It works by inhibiting the synthesis of bacterial cell walls, leading to cell lysis and death. Penicillin is effective against a wide range of Gram-positive bacteria, including Streptococcus pneumoniae, Streptococcus pyogenes, and some strains of Staphylococcus aureus. However, it is not effective against most Gram-negative bacteria due to their outer membrane, which acts as a barrier to penicillin penetration.
4. Chloramphenicol: Chloramphenicol is a broad-spectrum antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. It is effective against a wide range of both Gram-positive and Gram-negative bacteria, as well as some anaerobic bacteria. Chloramphenicol is used to treat various bacterial infections, including respiratory tract infections, typhoid fever, and bacterial meningitis. However, due to its potential to cause serious side effects, such as bone marrow suppression, its use is limited to certain situations where other antibiotics are not suitable.
In summary, while Ofloxacin, Vancomycin, and Chloramphenicol are broad-spectrum antibiotics effective against a wide range of bacteria, Penicillin primarily targets Gram-positive bacteria and is not as effective against Gram-negative bacteria. Each antibiotic has its unique mechanism of action and spectrum of activity, making them valuable tools in the treatment of bacterial infections. |
