Cmbm- Exam 3- Gram Negative Bacteria

Front 1

What portion of the LPS is responsible for endotoxic shock?

Back 1

Lipid A

*Hypotension is the most clinically important result of endotoxic shock

Front 2

Which class of Enterobacteriaceae are all oxidase negative?

Back 2

Enterobacteriaceae

Front 3

What major gram negative pathogen causes UTI?

Back 3

Escherichia coli

*Also causes neonatal meningitis

Front 4

Which class of Enterobacteriaceae causes dysentery?

Back 4

Shigella

*non-lactose fermenter

Front 5

Which gram (-) bacteria causes Gastroenteritis and Typhoid fever?

Back 5

Salmonella

*non-lactose fermenter

Front 6

Which bacteria do alcoholics tend to have problems with?

Back 6

Klebsiella

*Causes pneumonia in alcoholics

Front 7

Which 3 Enterobacteriaceae ferment lactose?

Back 7

Escherichia, Enterobacter, Klebsiella

*Non-lactose fermenters are Salmonella, Shigella, Proteus

Front 8

K1 strains of Escherichia coli are associated with what disease?

Back 8

Neonatal meningitis

Front 9

Which class of Enterobacteriaceae is characterized by "Swarming Motility"?

Back 9

Proteus mirabilis

*non-lactose fermenter

Front 10

Which bacteria is the 2nd most common cause of UTI and can cause kidney stones due to action of Urease?

Back 10

Proteus mirabilis

Front 11

Which bacteria do Cystic Fibrosis patients usually die from?

Back 11

Psuedomonas aeruginosa

*Can infect any body tissue

Front 12

Which molecule located on the outer membrane of Neisseria helps distinguish it from other bacteria?

Back 12

LOS

*can also undergo antigenic and phase variation (difficult to make vaccines)

Front 13

What is the major structural difference between Neisseria meningitis and Neisseria gonorrhea?

Back 13

N. meningitidis makes a capsule

*N. gonorrhea does NOT make a capsule

Front 14

What are the two Th1 signals required for macrophage activation?

Back 14

1) IFN-y (primary signal)
2) CD40L (makes macrophage responsive to IFN-y)

Front 15

Which two cells secrete IFN-y?

Back 15

Th1 cells and NK cells

Front 16

Macrophage activation by Th1 cells causes increased expression of what 4 molecules?

Back 16

1) Class II MHC (engage Th1 TCR- signal 1)
2) B7 (bind CD28 on Th1- signal 2)
3) CD40 macrophage activation w/ CD40L)
4) TNF-R (better TNF interaction)

Front 17

What is the result of IFN-y binding to IFN-y macrophage receptors?

Back 17

1) Killing of phagocytosed microbes (production of ROS, NO, enzymes)
2) Secretion of cytokines
3) Increased MHC and B7 molecules

Front 18

Which molecule upregulates macrophage's sensitivity to IFN-y?

Back 18

CD40/CD40L interaction

Front 19

Which cytokine is released by the APC (macrophage) to promote Th1 differentiation?

Back 19

IL-12

*Naive CD4+ T cell differentiates into Effector T cell (differentiated Th1 cell)

Front 20

Which cytokine is released by an Effector T cell to activate the macrophage?

Back 20

IFN-y

Front 21

What occurs if antigen is not cleared during delayed type hypersensitivity?

Back 21

Granulomatous hypersensitivity

*Persistant T cell activation -> Cytokine release -> Macrophage differentiation into Epithelioid cells -> secrete TNFa

Front 22

Where are the antigens usually derived from in cells expressing MHC I complex?

Back 22

Within the APC (typically viral)

*Class 1 MHC may also present peptides derived from microbes that have been phagocytized by dendritic cells (cross-presentation)

Front 23

In which situations would CD4+ T cell be required to fully activate CD8+ cells and their differentiation into functional CTLs?

Back 23

CD8+ T cell response to:
1) Latent viral infections
2) Oran transplants
3) Tumors

*All 3 produce weak immune responses

Front 24

In what 2 ways can CD4+ T cells help CD8+ T cell differentiation?

Back 24

1) Secretion of necessary cytokines
2) Production of CD40L (binds CD40 on APCs and makes them better at promoting CD8 T cell activation)

Front 25

What two cytotoxins are contained in lytic granules?

Back 25

1) Perforin- creates channel in target cell for granzymes to enter
2) Granzymes- induce apoptosis of target cell

*Apoptosis also induced via Fas-FasL interaction

Front 26

What type of lymphocyte are most NK cells?

Back 26

Large granular lymphocytes

*NK cells DO NOT recognize antigen via antigen receptor

Front 27

What do NK activating receptors recognize?

Back 27

Stress proteins on surface of target cells

Front 28

What do NK inhibitory receptors recognize?

Back 28

MHC I complex

*If normal MHC I complex, NK does not kill (need NO MHC I)

Front 29

Which cytokine is released by NK cell to activate macrophages?

Back 29

IFN-y