There is much between gram-positive and gram-negative bacteria. They are different on the base of the cell wall, cell wall compositions, gram stains, antibiotics, and their toxins(endotoxin, exotoxins).
Here we will elaborate on the difference between gram-positive and gram-negative bacteria is the base of gram stain.
Gram stain was first prepared by the Christian Gram in 1884. In this stain, bacteria are first treated with crystal violet, which turns it blue, in the next step, crystal iodine is used. In the third step decolorizer (Acetone) is applied which removes the stains on gram-negative bacteria. Finally, counterstain is used which colorizes the gram-negative bacteria.
Gram-positive bacteria retain the violet color, while gram-negative not. This difference occurs due to multilayers of peptidoglycan (20 to 80 nm) in gram-positive as compare to few-layer in gram-negative (2 nm peptidoglycan) bacteria.
Gram-positive bacteria have 70 to 80 % murein, while gram-negative have only 10 to 20 %. Teichoic acid exists in gram +ve while it did not present in gram -ve.
The difference between gram-positive and gram-negative bacterial flagella is that Gram-positive bacteria contain two rings in their basal bodies while gram-negative have twice as many rings in their basal bodies.
Gram-negative bacteria have lipopolysaccharide, periplasmic space, and out the membrane, gram-negative lakes.
Gram-positive bacteria are sensitive to penicillin, while gram-negative are not.
Differences between the structure of a gram-positive and gram-negative bacterial cell wall
Following are the differences between the structure of a gram-positive and gram-negative bacterial cell wall.
|Gram-Positive Bacteria||Gram-Negative Bacteria|
|1. It has Teichoic acid||It has periplasmic space|
|2. It has thick layers of peptidoglycan||Gram -ve bacteria have an outer membrane|
|3. It has two basal bodies in their flagella||It has 6 to 8 basal bodies in its flagella.|
Similirities between the structure of a gram-positive and gram-negative bacterial cell wall
There are some similarities between the structure of a gram-positive and gram-negative bacterial cell wall.
- Both gram positive and gram negative bacteria has flagella.
- Both has capsule.
- Both kindes of bacteria has Cytoplasmic membrane.
- They have pilus.
Gram positive and gram negative bacteria name list
Here is the list of Gram-positive and gram-negative bacteria names.
List of gram positive bacteria
- Streptococcus (Pneumonia, cellulitis)
- Staphlococcus (Abscess)
- Listeria (Meningitis)
- Bacillus (Anthrox)
- Clostridium (Tetnus, Gas gangren)
- Nocardia (Nocardiosis)
- Actinomyces (Actinomycosis)
List of gram Negative bacteria and their diseases
- E.coli (UTI, Diarrhea)
- Hemophilus Influenza (Respirotory)
- Pseudomonas (Aerobes, Pneumonia)
- Salmonella (Typhoid fever)
- Shigella (Entericolitis)
- Chlamydia (Urethritis)
- Compylobactor (Enterocolitis)
- Helicobactor (Peptic ulcer)
- Vibrio (Cholera)
- Proteus (UTI)