You are a third-year medical student working with Infectious Disease and are presented with a Gram-staining for a patient, showing a pink rod-shaped bacteria. The physician you are working with lists some of the characteristics of Gram-positive and negative bacteria. Which of the following would NOT be a characteristic of the bacteria observed on the Gram stain
Cytoplasmic membrane
Periplasmic space
Thick peptidoglycan layer
Lipoproteins
To determine which characteristic would NOT be associated with the observed Gram-stained bacteria, we need to review the characteristics of Gram-positive and Gram-negative bacteria.
Gram-positive bacteria have the following characteristics:
1. They retain the crystal violet stain and appear purple or blue on Gram staining.
2. They have a thick peptidoglycan layer in their cell wall.
3. They lack an outer membrane.
4. They have a cytoplasmic membrane.
Gram-negative bacteria, on the other hand, have the following characteristics:
1. They do not retain the crystal violet stain and appear pink or red on Gram staining.
2. They have a thin peptidoglycan layer in their cell wall.
3. They have an outer membrane containing lipopolysaccharides (LPS).
4. They have both a cytoplasmic membrane and a periplasmic space located between the cytoplasmic membrane and outer membrane.
Given this information, the characteristic that would NOT be associated with the observed bacteria is "Thick peptidoglycan layer". This is because the Gram-negative bacteria have a thin peptidoglycan layer, while Gram-positive bacteria have a thick peptidoglycan layer. Therefore, the correct answer is "Thick peptidoglycan layer".