Question

Why are gram-negative microbes and their related property of endotoxin of great concern to human health? Use the organism Neisseria meningitidis, and the resultant septicemia known as meningococcemia, to BRIEFLY apply the important concepts related to this question. Is there prevention for this outcome?

Answer 1

Gram-negative bacteria are characterized by their inability to retain crystal violet stain, which is used to differentiate between gram-positive and gram-negative bacteria. They are of great concern to human life as they cause various bacterial infections. Most of the gram-negative bacteria produce endotoxins.

• Endotoxins are complex molecules of lipopolysaccharides
• Causes fever by the production of interleukins
• The gram-negative bacteria are less antigenic, the immune system cannot easily form antibodies

Neisseria meningitidis causes meningitis. It colonizes the oropharynx, and enter the blood circulation through the transcytosis. The endotoxin causes the internal haemorrhage. After entering into the cetral nervous system, it disrupt the blood-brain-barrier (BBB) and access the cerebrospinal fluid. Meningococcemia is the systemic infection caused by this organism.

This condition can be prevented by vaccination against the Neisseria meningitidis.