Question

A narrow spectrum antibiotic is active against:
(A) gram positive and gram negative bacteria
(B) gram negative bacteria only
(C) single organism or one disease
(D) both gram positive and gram negative bacteria

Answer 1

Hint: Antibiotic is a medicine used for destroying bacteria. They act against bacterial infections not viruses.

Complete step by step answer:
Let us first discuss how antibiotics act. Antibiotics are one of two types.
Narrow spectrum antibiotics: They target a few types of bacteria. They are active against gram positive or gram negative bacteria.
Broad spectrum antibiotics: They target many types of bacteria and are not specific in action.
Both types of antibiotics work well to treat infections.
Some examples of narrow spectrum antibiotics are penicillin, the macrolides and vancomycin.
Some examples of broad spectrum antibiotics are aminoglycosides, quinolones and some synthetic penicillin.
Narrow spectrum bacteria are used for specific infections when microorganism is known and will not kill normal organisms in the body.
Therefore, from the above explanation the correct option is (A) gram positive and gram negative bacteria.

Additional Information:
Gram positive bacteria have a very thick cell wall of protein called peptidoglycan concentration.
Gram negative bacteria have a thin peptidoglycan layer.
Gram negative bacteria are more dangerous as disease organisms. This bacterium is harder to kill due to the thick wall of proton.
They have their name as gram negative and gram positive because:-
1. In a gram stain test, gram positive bacteria yield a positive result.
2. On the other hand, gram-negative bacteria don’t hold the dye.
Some natural antibiotics like Garlic, Honey, Cabbage, Raw apple, fermented food etc help to kill gram-positive and gram negative bacteria.

Note:
Narrow spectrum antibiotics are used for specific infections because they target few bacteria.
Amoxicillin and cephalexin are used as narrow spectrum antibiotics.