The correct answer is option 4. Penicillin G.
Antibiotics can be classified into two main categories based on their spectrum of activity: narrow-spectrum and broad-spectrum antibiotics.
1. Narrow-Spectrum Antibiotics:
Narrow-spectrum antibiotics are effective against a specific group of bacteria. These antibiotics target a limited range of bacteria, usually either Gram-positive or Gram-negative bacteria. Narrow-spectrum antibiotics are more selective in their action, and they are often preferred when the causative organism is known.
2. Broad-Spectrum Antibiotics:
Broad-spectrum antibiotics are effective against a wide range of bacteria, both Gram-positive and Gram-negative. They are less selective and can target a variety of bacterial species. Broad-spectrum antibiotics are commonly used when the specific pathogen is unknown or when there is a need for coverage against a broad range of potential bacteria.
Now, let's look at the antibiotics mentioned in the question:
(1) Vancomycin: Vancomycin is primarily effective against Gram-positive bacteria, making it a narrow-spectrum antibiotic.
(2) Chloramphenicol: Chloramphenicol is a broad-spectrum antibiotic, effective against both Gram-positive and Gram-negative bacteria.
(3) Amoxicillin: Amoxicillin is a broad-spectrum antibiotic belonging to the penicillin group. It is effective against a wide range of bacteria.
(4) Penicillin G: Penicillin G is a classic narrow-spectrum antibiotic, primarily effective against Gram-positive bacteria. It is part of the penicillin class of antibiotics.
So, among the options provided, Penicillin G (option 4) is an example of a narrow-spectrum antibiotic. It is important to note that the choice of antibiotic depends on factors such as the suspected or identified pathogen and its sensitivity to the antibiotic, as well as considerations like allergies and patient-specific factors. |
