General Microbiology Questions

Question 1

What is the definition of an atypical bacteria?

Answer 1

Bacteria that do not get colored by gram-staining but rather remain colorless: they are neither Gram-positive nor Gram-negative

Question 2

What is the definition of a Gram positive bacteria?

Answer 2

Gram-positive bacteria have thick cell walls made of peptidoglycan. In a Gram stain test, these organisms yield a positive result. The test, which involves a chemical dye, stains the bacterium’s cell wall purple.

Question 3

What is the definition of a Gram negative bacteria?

Answer 3

Gram-negative bacteria have thin, complex cell walls. In a Gram stain test, these organisms yield a negative result. They do not retain the crystal violet stain used in Gram staining.

Question 4

How do Gram negative bacteria create a toxic reaction?

Answer 4

The outer membrane is covered with lipopolysaccharides whose lipid A component can cause a toxic reaction when lysed by immune cells. This toxic reaction may lead to hypotension, respiratory failure, reduced oxygen delivery, and lactic acidosis – manifestations of septic shock.