Week 7: Infection + Epidemiology

Question 1

Give an example of amensalism and explain why it is this case

Answer 1

Fungus secreting antibiotic is a good example because the fungus neither benefits nor is harmed, yet it harmed surrounding bacteria

Question 2

Give example of commensalism and explain why it is this case

Answer 2

Mites in hair follicles because they benefit while neither harming nor benefiting the host

Question 3

Where are transient microbiota found?

Answer 3

In the same places as resident microbiota, they just stay there for shorter time periods

Question 4

Why can’t transient microbiota persist in the body?

Answer 4

-competition from other microbes
-immune cells remove them
-chem or physical body changes

Question 5

Describe acquisition of baby microbiome

Answer 5

Begins to develop during birthing process. Breast milk IgA

Question 6

What conditions give opportunistic pathogens chance to establish infection/disease?

Answer 6

-unusual site of body
-immune suppression
-change in microbiome content
-stress

Question 7

List the 3 types of reservoirs

Answer 7

-humans
-animals
-nonliving matter (fomites)

Question 8

Name nonliving reservoirs

Answer 8

Soil, water, and food

Question 9

Name the 3 main portals of pathogenic entry

Answer 9

Skin, mucous membranes, and placenta

Question 10

Describe the parenteral route

Answer 10

It’s not a true portal of entry, but bypasses GI tract and other main portals of entry via intravenous route

Question 11

List virulence factors

Answer 11

-adhesion factors
-biofilms
-extracellular enzymes
-toxins
-antiphagocytic factors

Question 12

Which type of bacteria secrete endotoxins and exotoxins?

Answer 12

Endotoxins = Gram-negative
Exotoxins = Gram-positive and negative

Question 13

Which causes fever? Exotoxins or endotoxins?

Answer 13

Endotoxins

Question 14

What does latrogenic mean?

Answer 14

Infection acquired from medical procedures

Question 15

What can cause superinfections?

Answer 15

Antibiotics that inhibit some resident microbiota and allow other microbes to live

Question 16

What’s the most effective way to avoid hosptital-acquired infections?

Answer 16

Handwashing

Question 17

List the 3 factors that play a role in healthcare-associated infections

Answer 17

1. Immunocompromised ppl
2. Transmission among staff + patients
3. Microbes present in hospital

Question 18

List the stages of infectious disease

Answer 18

1. Incubation period
2. Prodromal period
3. Illness
4. Decline
5. Convalescence

Question 19

What is the prodromal period?

Answer 19

Vague, general symptoms. You’re starting to get sick

Question 20

What is convalescence?

Answer 20

No signs + symptoms, but still infectious