Challenges in Microorganisms

Question 1

What are the types of organisms that can cause disease in humans?

Answer 1

Viruses
Bacteria
Fungi
Protozoa
Helminths (multicellular)
Prions (not a microorganism)

Question 2

What are some examples of microorganisms that cause death in humans?

Answer 2

PCP (Pneumocystis pneumonia) - fungus; common in AIDS patients
Toxoplasma gondii- protozoa; that creates brain cysts
Schistosomiasis- helminth; transmitted through water
Trachoma- bacterial disease; (chlamydia) causes blindness

Question 3

What are the different transmission routes microorganisms use to infect hosts

Answer 3

Physical contact
Inhalation
Ingestion
Vectors

Question 4

What does zoonotic infection mean? What does One Health mean?

Answer 4

-An inter-host infection (fine in one host species not in the other)
- One health= animals and humans health is linked/opportunity for infections to spread animals <=> humans
eg. Ebola, SARS,

Question 5

Give some examples of diseases that threaten global health.
Give some ways to control them

Answer 5

Ebola (bat origin) – public health and vaccine
Zika (primate origin) – generation herd immunity
COVID-19 (bat origin) – public health and vaccine

Question 6

How do host-microbe relationships help develop treatment for disease/ inflammatory conditions?

Answer 6

• Can alter microorganisms for vaccination (live attenuated, killed, subunit, viral vector)
• Use helminths to treat asthma and chrons

Question 7

What are the main physical barriers?

Answer 7

• Skin
• Mucosal
• Tears
• Sweat
• Ear wax

Question 8

What are chemical barriers?

Answer 8

Skin– fatty acids, b defensins
Lungs– pulmonary surfacant, a defensins
Gut– low pH, pepsin, a defensins
Ears/nose/oral– Lysozyme in saliva and tears, b defensins

Question 9

How do pathogens break the barrier?

Answer 9

• Skin breaks, wounds/ burns (ie staph)
• Animal bites (ie rabies)
• Insect bites (ie malaria)
• Parasites burrow through skin (ie hookworms)

Question 10

What cells are apart of the adaptive immune system?

Answer 10

B cells
T cells (including CD4 & CD8, Th, Tregg, CTL)
Antibodies

Question 11

What cells are a part of the innate immune system?

Answer 11

• Mast cell
• DC
• Macrophage
• NK
• Granulocytes (including eosinophils, neutrophils, basophils)
• complement proteins

Question 12

What are the functions of the cells of the innate immune system: macrophages, neutrophils, NK, complementing proteins

Answer 12

• Macrophages/neutrophils: phagocytosis
• Eosinophils/ Neutrophils: fire cytotoxic granules at pathogens
• Complementing proteins: punches holes in bacteria
• NK: binds infected cells and kills them

Question 13

What are the main functions of innate system?

Answer 13

• detecting infection
• killing pathogens
• recruiting cells to the infection site
• activating and directing cells of the adaptive immune system

Question 14

What are the functions of the following cells:
- Th
- Tregg
- CTL (cytotoxic T cells)
- B cells

Answer 14

• Th (talker cells)
• Tregg (talk but stop immune response)
• CTL (kill infected cells)
• B cells (produce antibodies)

Question 15

What do cells use to communicate during immune response?

Answer 15

1. Cytokines
2. contact dependent cell cell interactions

Question 16

What role do the spleen and lymph nodes play in immune response?

Answer 16

• They are sites where specialised cells meet and coordinate immune response
• Needed to initate adaptive response