MMI Topic 12

Question 1

What is the microbiome

Answer 1

The community of microbes (their genetic materials, and their secreted metabolites) that colonize various anatomical sites of the body

Question 2

What is the microflora/microbiota

Answer 2

terms used interchangeably with microbiome BUT they are more specifically referring to microorganisms only

Question 3

What is microbial antagonism

Answer 3

it is the competition between microbes

Question 4

What are bacteriocins

Answer 4

a protein produced by one bacteria to protect the host from other bacterias

Question 5

What are probiotics

Answer 5

live microbes that are intentionally ingested to provide health benefits

Question 6

What is a prebiotic

Answer 6

ingredients in food that induce the growth or activity of beneficial microbes

Question 7

Describe fecal transplants

Answer 7

process in which fecal bacteria from a healthy person is introduced to a recipient in the hopes of restoring healthy colonic microflora

Question 8

What is an opportunistic infection

Answer 8

infection caused by pathogens that take advantage of a an opportunity not normally available such as weakened immune system, altered microbiota, or breached integumentary barriers

Question 9

What is pathogenicity

Answer 9

ability of a microbe to cause disease

Question 10

What is virulence

Answer 10

how harmful a pathogen is to a host

Question 11

Describe the parenteral route

Answer 11

pathogen is inserted directly into the blood or the tissue beneath the skin or mucous membranes.
ex. insect bite

Question 12

What are invasins

Answer 12

a class of proteins associated with the penetration of pathogens into the host cells

Question 13

Describe antigenic variation`

Answer 13

when pathogens change the structure on their surfaces so the immune system does not recognize them during re-infection

Question 14

What are cytopathic effects

Answer 14

Damage or death to the host cell (usually due to virus replication

Question 15

What is septic shock and how does sepsis develop

Answer 15

severe and potentially fatal condition that occurs when sepsis leads to extremely low BP. Sepsis develops when the body has an extreme reaction to infection

Question 16

What is a superantigen

Answer 16

proteins (usually bacterial) that stimulate a massive immune response

Question 17

Describe endotoxins

Answer 17

Lipopolysaccharides on the outside of gram-negative bacteria cells that is released when the cell dies causing an immune system reaction

Question 18

Describe exotoxins and how they are classified

Answer 18

proteins secreted by pathogens (usually gram + ones) that may be waste products or designed to gain access to host nutrients. they are classified based on their function

Question 19

Describe enterotoxins

Answer 19

exotoxin that affects the intestinal tract

Question 20

Describe Tetanus toxin

Answer 20

it is a neurotoxin that inhibits neuron function

Question 21

Describe botulism toxin

Answer 21

neurotoxin that causes paralysis

Question 22

What is E. choli O157:H7

Answer 22

Enterohemorrhagic E. choli. Causes bloody diarrhea and no fever. can also cause hemolytic-uremic and kidney failure

Question 23

Name 5 places microbes live in the human body

Answer 23

1. Skin
2. Conjuctiva (ex. surface of the eye)
3. Upper respiratory tract (ex. mouth, nose/throat)
4. Lower digestive system (intestines)
5. Urinary & reproductive system (urethra & vagina)

Question 24

A patient dies of an E. choli infection after an intestinal puncture. Why does this microbe, which normally lives in the colon and is not harmful, killed this patient

Answer 24

in this case, the E. choli was an opportunistic pathogen. Because there was a puncture in his intestine the E. choli took advantage of the opportunity to infect.

Question 25

What are mechanisms of pathogenicity

Answer 25

Requirements for infection and disease

Question 26

What are the 6 mechanisms of pathogenicity

Answer 26

1. Gain access (portals of entry)
2. Be present in sufficient numbers to cause infection
3. Attach/adhere to host cells
4. Penetrate host defences
5. Have virulence (be able to damage host cells)
6. Be transmissible to new hosts (exit one host and infect another)

Question 27

What are the 5 stages of disease and a brief description

Answer 27

1. Incubation period- no signs/symptoms
2. Prodromal period- vague general symptoms
3. Illness- most severe signs/symptoms (death can occur)
4. Decline- Symptoms decline
5. Convalescence- no symptoms

Question 28

How do Botulism toxins work?

Answer 28

caused by ingesting food infected with the toxin. it prevents the release of an inducing neurotransmitter that contracts muscles causing paralysis

Question 29

How to tetanus toxins work

Answer 29

it prevents the release of an inhibitory neurotransmitter that stops muscle contraction and causes muscle spasms and spastic paralysis

Question 30

what is the difference between sign vs symptoms

Answer 30

sign- a characteristic measured by an observer

symptom- a change in body function that is described by the patient

Question 31

Chronic vs acute disease

Answer 31

chronic- persistent or long lasting

acute- a rapid onset or short course of disease

Question 32

Sub-clinical vs latent disease

Answer 32

sub-clinical- an asymptomatic infection

latent- where the pathogen lies dormant in the body for a period of time