Question

Which of the following is a narrow spectrum antibiotic?
Penicillin G
Dettol
Aspirin
Analgin

Answer 1

Hint: An antibiotic with a narrow spectrum is an antibiotic that can kill or inhibit only limited bacterial species. Examples of narrow-spectrum antibiotics include vancomycin, fidaxomicin, and sarecycline.

Complete answer:
Benzylpenicillin (Penicillin G) is a narrow spectrum antibiotic used for the treatment of susceptible bacterial infections.
It is a natural antibiotic of penicillin, given intravenously or intramuscularly because of slow oral absorption.
Penicillin (PCN or pen) is a group of antibiotics originally extracted from popular moulds called penicillium moulds, including penicillin G, penicillin V, procaine penicillin, and penicillin benzathine. Among the first drugs penicillin antibiotics are successful against many bacterial infections caused by staphylococci and streptococci.
Although the number of penicillin-resistant bacteria is growing, penicillin can still be used to treat a wide variety of infections caused by those susceptible bacteria, including those in the Streptococcus, Staphylococcus, Clostridium, Neisseria, and Listeria genera. The following list shows minimum inhibitory concentration sensitivity data for a few medically significant bacteria:
Listeria monocytogenes: from less than or equal to 0.06 μg/ml to 0.25 μg/ml
Neisseria meningitidis: from less than or equal to 0.03 μg/ml to 0.5 μg/ml
Staphylococcus aureus: from less than or equal to 0.015 μg/ml to more than 32 μg/ml

Advantages of Antibiotics:
Narrow-spectrum antibiotics allow only certain undesirable species of bacteria (i.e. causing disease) to be destroyed or inhibited. As such, it leaves the beneficial bacteria undisturbed and therefore minimises collateral damage to the microbiota.
Low tendency to develop bacterial resistance.

Disadvantages of Antibiotics:
The exact species of bacteria causing the disease is always unclear, in which case narrow-spectrum antibiotics can't be used, and often broad-spectrum antibiotics are used. In order to determine the exact species of bacteria causing the disease, clinical specimens must be taken in a clinical microbiology laboratory for antimicrobial susceptibility examination.

Note: Antibiotics are medicines which help avoid bacterial infections. They do this by killing and/or blocking the bacteria from cloning or reproducing themselves. Any medication that destroys germs in the body is literally an antibiotic. The term antibiotic means "against life."