III - Infection Biology

Question 1

Microbes that can cause disease

Answer 1

pathogens

Question 2

Pathogens that cause disease only in the immunocompromised

Answer 2

opportunistic pathogens

Question 3

Measure of a microbe’s ability to cause disease

Answer 3

virulence

Question 4

Virulence is determined by

Answer 4

virulence factors - capsule, endotoxin, exotoxin

Question 5

Number of organisms required to cause disease in 50% of the population

Answer 5

ID50

Question 6

Presence of microbes, symptoms of disease

Answer 6

infection

Question 7

Mechanisms of Bacterial Disease

Answer 7

production of toxins, induction of inflammation

Question 8

Human-Human Bacterial Transmission

Answer 8

sexual, fecal-oral, inhalation, transplacental, blood

Question 9

Non-Human-Human Bacterial Transmission

Answer 9

soil, water, animal, vector, feces, fomites

Question 10

Mediates attachment of bacteria

Answer 10

pili

Question 11

Mediates strong adherence to the surface of human cells

Answer 11

glycocalyx

Question 12

Surface protein of Salmonella and E. coli that mediate binding to endothelium and to extracellular proteins such as fibronectin

Answer 12

curli

Question 13

Bacterial Invasion: Spread through subcutaneous tissue

Answer 13

collagenase, hyaluronidase

Question 14

Bacterial Invasion: Accelerates formation of a fibrin clot coating the organisms with a layer of fibrin

Answer 14

coagulase

Question 15

Bacterial Invasion: Allows adherence to mucous membranes

Answer 15

IgA protease

Question 16

Bacterial Invasion: Destroys both neutrophilic leukocytes and macrophages

Answer 16

leukocidin

Question 17

Bacteria with IgA Protease

Answer 17

Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Neisseria gonorrhoeae

Question 18

Protects against phagocytosis

Answer 18

polysaccharide capsule

Question 19

Anticapsular antibodies allow more effective phagocytosis to occur

Answer 19

Opsonization

Question 20

Antiphagocytic cell wall protein of S. pyogenes

Answer 20

M Protein

Question 21

Cell wall protein of S. aureus that prevents complement activation

Answer 21

Protein A

Question 22

Exotoxin: Source

Answer 22

gram (+), gram (-)

Question 23

Exotoxin: Secreted from cell?

Answer 23

yes

Question 24

Exotoxin: Chemical Compound

Answer 24

polypeptide

Question 25

Exotoxin: Location of Genes

Answer 25

plasmid, bacteriophage

Question 26

Exotoxin: Toxicity

Answer 26

high

Question 27

Exotoxin: Antigenicity

Answer 27

high

Question 28

Exotoxin: Vaccine

Answer 28

toxoids

Question 29

Exotoxin: Heat Stability

Answer 29

destroyed at 60°C (except Staphylococcal enterotoxin)

Question 30

Exotoxin: Typical Diseases

Answer 30

tetanus, botulism

Question 31

Endotoxin: Source

Answer 31

gram (-)

Question 32

Endotoxin: Secreted from cell?

Answer 32

no

Question 33

Endotoxin: Chemical Compound

Answer 33

lipopolysaccharide

Question 34

Endotoxin: Location of Genes

Answer 34

bacterial chromosome

Question 35

Endotoxin: Toxicity

Answer 35

low

Question 36

Endotoxin: Antigenicity

Answer 36

low

Question 37

Endotoxin: Heat Stability

Answer 37

stable at 100°C for 1 hour

Question 38

Endotoxin: Typical Diseases

Answer 38

meningococcemia

Question 39

Polypeptides secreted by certain bacteria that alter specific cell functions resulting in the symptoms of disease

Answer 39

exotoxins

Question 40

Exotoxins: Active subunit, toxic, less toxic in toxoids

Answer 40

A subunit

Question 41

Exotoxins: Binding subunut

Answer 41

B subunit

Question 42

All exotoxins are heat-labile except

Answer 42

Staphylococcal enterotoxin

Question 43

MoA of Exotoxins: Diphtheria, cholera, E.coli heat-labile toxin, pertussis

Answer 43

ADP-ribosylation

Question 44

MoA of Exotoxins: Toxic Shock Syndrome, Staphylococcal enterotoxin, erythrogenic toxin

Answer 44

Superantigen

Question 45

MoA of Exotoxins: Tetanus, botulinum, lethal factor of anthrax toxin, Scalded Skin toxin

Answer 45

Protease

Question 46

MoA of Exotoxins: Clostridium perfringens alpha toxin

Answer 46

Lecithinase

Question 47

Can elicit widespread activation of the complement and coagulation cascades

Answer 47

Superantigens

Question 48

Lipoplysaccharides located in the outer membrane of gram (-) bacteria

Answer 48

endotoxins

Question 49

Toxic component of LPS

Answer 49

Lipid A

Question 50

Induces the overproduction of cytokines such as TNF and IL-1, activates the complement and coagulation cascade resulting in disseminated intravascular coagulation

Answer 50

Lipid A

Question 51

All bacteria have cell walls composed of peptidoglycan except

Answer 51

Mycoplasma pneumoniae

Question 52

Only gram (+) bacteria with endotoxin

Answer 52

Listeria monocytogenes

Question 53

All bacterial capsules are composed of polysaccharide except

Answer 53

Bacillus anthracis

Question 54

All exotoxins are heat-labile except

Answer 54

Staphylococcal enterotoxin

Question 55

Determine whether antibodies are present in a patient's serum, detect the antigens of the organism in tissues or body fluids, at least a fourfold increase in titer between the acute and convalescent samples, IgM antibody for acute infection

Answer 55

Serologic Tests

Question 56

Nucleic acid amplification tests, nucleic acid probes, nucleic acid sequence analysis

Answer 56

Molecular Tests

Question 57

Highly specific, sensitive, faster than culture

Answer 57

Molecular Tests

Question 58

Useful for bacteria that are difficult to culture such as Chlamydia and Mycobacterium

Answer 58

Molecular Tests