Microbiology Endotoxin, Exotoxin And Bacteria Genetics (Pages 143-145)

Front 1

What are the bugs with superantigens?

Back 1

S. aureus and S. pyogenes

Front 2

What does the S. aureus superantigen cause?

Back 2

1. TSST-1 superantigen causes toxic shock syndrome (fever, rash, shock).
2. enterotoxins that cause food posioning
3. exfoliatin which causes staphylococcal scalded skin syndrome

Front 3

What does the S. pyogens superantigen cause?

Back 3

1. scarlet fever
2. erythrogenic toxin causes toxic shock like syndrome

Front 4

What are the 4 bugs that make ADP ribosylating A-B toxins?

Back 4

1. Corynebacterium diphtheriae
2. Vibrio cholerae
3. E. coli
4. Bordetella pertussis

Front 5

What does ADP ribosylating A-B toxin do? What does the A part and the B part do?

Back 5

It interferer's with host cell function
B (binding) component binds to a receptor on surface of host cell, enabling endocytosis
A (active) componenet then attaches an ADP-ribosyl to a host cell protein (ADP ribosylation), altering protein function

Front 6

What does ADP ribosylating A-B toxin of Corynebacterium diphtheriae do?

Back 6

Inactivates elongation factor (EF-2) - like Pseudomonas exotoxin A); causes pharyngitis and pseudomemebrane in throat

Front 7

What bug's exotoxin is similar to the bug that causes a pseudomembrane?

Back 7

Pseudomonas (exotoxin A)

The bug that causes a pseudomembrane is Corynebacterium diphtheriae

Front 8

What does the A-B toxin of Vibrio cholerae do?

Back 8

ADP ribosylation of G protein stimulates adenylyl cyclase; increaseing pumping of chloride into gut and decreases sodium absorption. Water moves into the gut lumen and causes voluminous rice-water diarrhea

Front 9

What does the A-B toxin of E.coli do?

Back 9

"liable like air; stable like ground"
1. Heat-labile toxin stimulates adenylate cyclase
2. heat stabile toxin stimulates guanylate cyclase
*both cause watery diarrhea

Front 10

What does the A-B toxin of Bordetella pertussis do?

Back 10

Increases cAMP by inhibiting Ga1; causes whooping cough; inhibits chemokine receptor, causing lymphocytosis

Front 11

What toxin is made by Clostridium perfringens and what does it cause?

Back 11

alpha toxin - causes gas gangrene; get double zone of hemolysis on blood agar

Front 12

What causes a double zone of hemolysis on blood agar?

Back 12

Clostridium perfringens

Front 13

What toxin blocks the release of inhibitory neruotransmitters GABA and glycine? What does it cause?

Back 13

C. tetani - causes lockjaw

Front 14

What toxin blocks the release of ach; causes anticholinergic symptoms, CNS paralysis, especially cranial nerves;

Back 14

C. botulinum - spores are found in honey and canned foods (causes floppy baby)

Front 15

What toxin is made by Bacillus anthracis?

Back 15

Edema factor - part of toxin complex, is an adenylate cyclase (which increases cAMP)

Front 16

What toxin is made by Shigella? What does that toxin do?

Back 16

Shiga toxin (also produced by E.coli) - cleaves host cell rRNA (inactivates 60S ribosome) also enhances cytokine release, causing HUS

Front 17

What bug also produces Shiga toxin besides Shigella?

Back 17

E.COli 0157:H7

Front 18

What toxin causes HUS?

Back 18

Shiga toxin

Front 19

What toxin does S. pyogenes make? What does the toxin do?

Back 19

Streptolysin O is a hemolysin; antigen for ASO antibody, which is use in the diagnosis of rheumatic fever

Front 20

What causes rheumatic fever?

Back 20

S. pyogenes (If ASO antibody positive could have rheumatic fever)

Front 21

What are the bacteria that are cAMP inducers?

Back 21

1. Vibrio cholerae
2. Pertussis toxin
3. E.coli (ETEC)
4. Bacillus anthracis

Front 22

What cAMP inducer toxin permanently activates Gs?

Back 22

"turns the "on" on"
Vibrio cholerae - causes rice water stools

Front 23

What does the pertussis toxin do to cAMP?

Back 23

"Pertussis turns the "off" off"
disables Gi, causing whooping cough
*also promotes lymphocytosis by inhibiting chemokine receptors

Front 24

What E.coli (ETEC) toxin is an inducer of cAMP?

Back 24

heat-labile toxin

Front 25

What cAMP inducer toxin includes edema factor, a bacterial adenylate cyclase (thus increasing cAMP)?

Back 25

Bacillus anthracis

Front 26

Which of the cAMP inducers act via ADP ribosylation to permanently activate endogenous adenylate cyclase (thus increasing cAMP)?

Back 26

Cholera, pertussis, and E.coli (ETEC)

Front 27

What cAMP inducer is a adenylate cyclase itself?

Back 27

anthrax edema factor

Front 28

What is endotoxin and where is it found?

Back 28

A lipopolysaccharide found in the cell wall of gram-negative bacteria (and listeria monocytogenes, the only gram positive bacterium with endotoxin)

Front 29

Is endotoxin heat stable or labile?

Back 29

Heat stabile

Front 30

!N-doxin is an integral part of what?

Back 30

gram Negative outer membrane

Front 31

What does endotoxin (especially lipid A) do?

Back 31

1. Activates macrophages: IL-1 = fever, TNF = fever, hemorrhagic tissue necrosis, and NO= hypotension (shock)
2. Activates complement (alternative pathway): C3a = hypotension, edema, C5a = neutrophil chemotaxis
3. Activates Hageman factor: coagualation cascade = DIC

Front 32

What are the four stages of the bacterial growth curve and what happens during each of them?

Back 32

1. Lag - metabolic activity without division
2. Log - rapid cell division
3. Stationary - nutrient depletion slows growth. Spore formation in some bacteria.
4. Death - prolonged nutrient depletion and buildup of waste products leads to death

Front 33

What is the name for the ability of bacteria to take up DNA from the environment?

Back 33

Transformation (also called competence)

Front 34

What bacteria do transformation?

Back 34

Many bacteria, especially SHiN - S. pneumoniae, H. influenzae, Neisseria (encapsulated bacteria that produce IgA protease)

Front 35

F+ x F- is called what?

Back 35

Conjugation - F+ plasmid contains genes required for conjugation process. bacteria without plasmid = F-. Plasmid is replicated and trasferred through pilus from F+ cell. Plasmid DNA only; no transfer of chromosomal genes

Front 36

Hfr x F- is called what?

Back 36

Conjugation. F+ plasmid can become incorporated into the bacterial chromosomal DNA, termed Hfr cell. Replication of incorporated plasmid DNA may include some flanking chromosomal DNA. Transfer of plasmid and chromosomal genes.

Front 37

Hfr x F- versus F+ x F-

Back 37

In F+ x F- only the transfer of the plasmid occurs in Hfr x F- you get transfer of the plasmid and chromosomal genes

Front 38

What are the two types of transduction?

Back 38

Generalized: a "packaging" event. lytic phage infects bacterium, leading to cleavage of bacterial DNA and synthesis of viral proteins. parts of bacterial chromosomal DNA may become packaged in viral capsid. phage infects another bacterium, transferring these genes.
Specalized: an "excision" event. lysogenic phage infects bacterium; viral DNA incorprated into bacterial chormosome. When page DNA is excised, flanking bacterial genes may be excised with it. DNA is packaged into phage viral capsid and can infect another bacterium

Front 39

What is transposition?

Back 39

Segment of DNA that can "jump" (excision and reincorporation) from one location to another, can transfer genes from plasmid to chromosome and vice versa. When excision occurs, may include some flanking chromosomal DNA,which can be incorporated into a plasmid and transferred to another bacterium.

Front 40

Genes for what 5 toxins are encoded in a lysogenic phage?

Back 40

ABCDE
A: ShigA-like toxin
B: botulinum toxin (certain strains)
C: cholera toxin
D: diphtheria toxin
E: erythrogenic toxin of streptococcus pyogenes