Cmbm- Exam 3- Bacterial Pathogenesis

Front 1

Define: pathogenicity

Back 1

The ability of of organism to cause disease

*infection does not always lead to disease

Front 2

What type of pathogen causes disease when immune or anatomical defenses are impaired?

Back 2

Opportunistic pathogens

*Unlike primary pathogens, opportunistic pathogens can be part of normal flora

Front 3

What are the three determinants of virulence in a bacterium?

Back 3

1) Structural
2) Biochemical
3) Genetic traits

Front 4

How can virulence move between bacteria?

Back 4

Virulence genes (horizontal gene transfer mechanisms)

Front 5

Which two factors are needed for specific mediated binding of bacteria to eukaryotic cells?

Back 5

1) Adhesion (molecule on bacteria interacts with host receptor)
2) Receptor (on surface of host cell)

Front 6

What is the term used to describe bacteria entering normally sterile sites and more susceptible tissue

Back 6

Dissemination

*Bacteria can destroy barrier (enzymes) or penetrate cells of barrier

Front 7

Which two mechanisms are used by bacteria to steal iron from its host?

Back 7

1) Siderophores
2) Iron binding outer membrane proteins

Front 8

What is a toxoid?

Back 8

A toxin that has been treated to eliminate the toxic qualities while retaining the antigenic properties

Front 9

What type of exotoxin induce uncontrolled T cell cytokine release?

Back 9

Super antigens

*Can lead to systemic shock

Front 10

Which class of toxin are antigenic?

Back 10

Exotoxins

Front 11

Which type of toxin only involves gram negative bacteria?

Back 11

Endotoxins

*Lipid A portion of LPS has toxic activity

Front 12

Which antibody would the bacteria coat itself in order to evade the complement system?

Back 12

IgA antibodies

*Do not bind complement

Front 13

What is the main trait that distinguishes something as a toxin?

Back 13

Toxins are products that ALONE cause disease

Front 14

Which type of toxin can be phage or plasmid encoded?

Back 14

Exotoxins

Front 15

Which phagocyte receptor interacts with LPS-CD14 complex, stimulating cell activation, cytokine synthesis and release?

Back 15

Toll-like receptor-4 (TLR-4)

*Produce a variety of effects (complement, coagulation, temp, circulatory, etc)

Front 16

Which two molecules are the principle mediators of many pathophysiological effects of endotoxins?

Back 16

Tumor necrosis factor (TNF)
Interleukin-1 (IL-1)

Front 17

Which type of toxin produces pathophysiological effects that are similar regardless of the bacterial origin?

Back 17

Endotoxins

Front 18

In A-B subunit internalized exotoxins, which subunit posses the toxic enzymatic activity?

Back 18

A (active) subunit

*B mediates binding and translocation of A into the cell

Front 19

Which exotoxin inactivates eukaryotic EF2, inhibiting protein synthesis and leading to cell death?

Back 19

Diptheria toxin

*encoded on prophage

Front 20

Which exotoxin increases cAMP and gives water diarrhea?

Back 20

Cholera Toxin

Front 21

Which exotoxin has 2 A subunits (1 Edema factor and 1 Lethal factor)?

Back 21

Anthrax toxin

Front 22

What type of toxins are adenylate cyclase toxin and cytotoxins A/B?

Back 22

Single subunit internalized exotoxins

Front 23

Which exotoxins oligomerize to form membrane pores?

Back 23

Hemolysins

*Examples: alpha toxin, streptolysin O, pneumolysin

Front 24

What type of toxin is Clostridium perringens alpha-toxin?

Back 24

Membrane-lytic enzyme

*Destroys lipids in eukaryotic membrane

Front 25

Which exotoxin causes erythema by disrupting cell-cell junctions?

Back 25

Staphylococcus aureus exfoliative exotoxin

Front 26

Name the three medically important superantigens

Back 26

1) Staphylococcus aureus toxic shock syndrome toxin (TSST-1)
2) Staphylococcus enterotoxin
3) Streptococcus pyogenes pyrogenic exotoxin

Front 27

How would you treat exotoxin-mediated disease?

Back 27

1) Antibody therapy
2) Neutralization of toxin
3) Anti-TNF antibody for endotoxic shock