What is the difference between Gram-positive and Gram-negative bacteria? Why is this distinction important to doctors?

Major difference between gram positive and gram negative bacteria is the composition of their cell wall.

Explanation:

Gram positive bacteria has a thick peptidoglycan in their cell wall whilst gram negative bacteria's cell wall has thin peptidoglycan.

Gram negative bacteria has the ability to resist antibiotics due to the lipoproteins in their cell wall. The lipoproteins covers the external part of bacterial cell protecting it from harmful chemicals, extreme heat and uv radiations.

Therefore doctors find it difficult to treat gram negative bacteria.