What is the importance of gram positive and gram negative bacteria?

Answer 1

Typical gram-positive bacteria are those staphylococci that produce boils; typical gram-negative bacteria are the bacilli that cause whooping cough; typical gram-variable bacteria are the bacilli that cause tuberculosis.

Answer 2

Basically gram negative bacteria contain only a thin layer of petidoglycan which is contained inside a secondary outer membrane composed of phospholipids and lipopolysaccharides. Gram positive bacteria have a thick layer of peptidoglycan that is exposed to the external environment. This secondary membrane, in particular the lipopolysaccharide layer of it, is related to pathogenicity in many gram negative bacteria. Medically speaking, most gram negative bacteria are pathogenic. If you are looking at a sample from a sick patient and you encounter a gram negative bacterial growth, you have likely discovered the source of the illness.

The secondary membrane can make it more difficult for antibiotics to permeate the cellular envelope and kill the bacteria. Therefore, higher rates of antibiotic resistance are seen among gram negative bacteria than among gram positive bacteria. Additionally, some factors of virulence, such as adhesion, can be expressed through proteins in the external membrane.

I would say the overall medical significance of gram negative bacteria is that they are more likely to be pathogens, and they often function as much nastier pathogens than their gram positive counterparts.

Answer 3

Gram-negative-- Refers to the property of many bacteria that causes them to not take up color with Gram's stain, a method which is used to identify bacteria.