Lecture 7

Question 1

Endotoxins

Answer 1

• only made by Gram (-) bacteria

- Lipid A of outer membrane

Question 2

Opportunistic Pathogen

Answer 2

• these are part of our normal flora
• but will cause disease if conditions change
  (ex: change in location/environment, in relative abundance, or immune suppression triggers the bacteria to become pathogenetic)

Question 3

Axenic

Answer 3

Areas on body that are free of normal flora

- ex: stomach

Question 4

Vehicle Transmission

Answer 4

• Airborne (dust and small droplets, travel 1m +) (opposite from droplet)
• Waterborne
• Foodborne

Question 5

Hemagglutinin

Answer 5

• an adhesion for influenza virus

Question 6

Quorum sensing (mechanism)

Answer 6

acylated-homoserine lactone (AHL)

• know this from notes

Question 7

Virulence factors (4 major types)

Answer 7

• Adhesion factors
• Extracellular enzymes
• Toxins
• Immune evasion

Question 8

Transmission of disease (3 types)

Answer 8

1. Contact transmission
2. Vehicle transmission
3. Vector transmission

Question 9

VIRULENCE

Answer 9

refers to the degree of pathogenicity

• level of virulence depends on two things:
  
  • level of sickness caused by disease
  • how transmittable the disease is

Question 10

2 key things for the initial establishment of disease

Answer 10

1. Portal of entry

2. Dosage

Question 11

Zoonoses

Answer 11

diseases that are spread from their usual animal host to humans

(animals are reservoir/animal born disease)

Question 12

Parasitism

Answer 12

One organism benefits while the other is harmed

- ex: Tuberculosis in lung

Question 13

PATHOGEN

Answer 13

disease causing microorganism

Question 14

Progress of Disease

Answer 14

• Incubation: time between entry of parasite and appearance of symptoms
• Prodromal: host-pathogen battle time (malaise)
• Illness: acute stage of disease (specific symptoms appear)
• Decline: symptoms fade
• Convalescence: return to normal

Question 15

Mutualism

Answer 15

both organism benefit

- ex: E. Coli gets sustainable environment and E. Coli give vitamin K

Question 16

Diseases only found in ___________ can potentially be eradicated by vaccination

Answer 16

human reservoir

Question 17

Exotoxins are produced by…

Answer 17

• produced by both Gram (+) and Gram (-)

Question 18

Membrane disrupting

Answer 18

• type of exotoxin

- poke holes in or degrade phospholipid bilayer

Question 19

Commensalism

Answer 19

One organism benefits while the other is indifferent
- ex: staphylococcus
on skin

Question 20

Exotoxins (3 type)

Answer 20

• Intracellular targeting
• Membrane disrupting
• Super antigens

Question 21

Intracellular targeting

Answer 21

• type of exotoxin

enter cell and disrupt cellular process, often “AB” exotoxins

Question 22

Quorum sensing

Answer 22

• Bacteria will express genes only if there are a sufficient number of pathogens (other bacteria) present

Question 23

carrier

Answer 23

a human reservoir that continues to shed disease agents without necessarily showing disease symptoms (Typhoid Mary)

Question 24

Contact transmission

Answer 24

Direct – person to person physical contact

Indirect – Fomites (ex. shared drinking glass)

Droplet – sneezing, coughing (large, travel less than 1m)

Question 25

Normal Microbiota (flora)

Answer 25

Microorganism that live as a part of our normal flora | - usually relationship is Mutualistic/Commensurate

Question 26

Tetanospasmin

Answer 26

a neurotoxic exotoxin that causes tetanus | - intracellular targeting (AB toxin)

Question 27

Toxemia

Answer 27

presence of toxins in blood

Question 28

pathogenicity islands

Answer 28

Genes encoding proteins involved in pathogenicity are clustered in the pathogen’s chromosome (a way for bacteria to save energy and not produce pathogenic genes if they are not needed )

Question 29

Super antigen

Answer 29

- type of exotoxin - stimulate excessive activation of immune system (overstimulation of the immune system)

Question 30

Extracellular Enzymes (func)

Answer 30

- Dissolve structural chemicals in the body | - Help pathogen maintain infection and invade further

Question 31

Vector Transmission

Answer 31

Biological – serve as hosts for the multiplication of pathogen (ex mosquitos, fleas) Mechanical – simply carry the pathogen, usually on their surface (ex flies and cockroaches)

Question 32

PATHOGENICITY

Answer 32

is the ability to produce disease

Question 33

Extracellular Enzymes | examples

Answer 33

Hyaluronidase, collagenase, coagulase, streptokinase, staphylokinase

Question 34

Three symbiotic relationships

Answer 34

- Mutualism - Commensalism - Parasitism