DIT Micro Basics and Toxins

Question 1

Lipotechoic acid is from where and elicits what?

Answer 1

G+ and can cause acute phase cytokine release

IL-1
IL-6
TNF alpha

Question 2

What is glycocalyx? What does it do? How is it different than fimbria?

Answer 2

Mediates adherance to surfaces (especially cathetes) polysaccharide

Fimbria binds to other cells and is glycoprotein

Question 3

What is a quelling reaction? What has positive reaction?

Answer 3

Anti capsular serum added to bacteria, and it will swell if it has a capsule (quelling causes swelling in capsules)

SHIiNE SKiPS

**Strep pneumo
**H influ
**Neisseria meningitidis
E coli (some strains)

Strep agalactiae
Klebsiella
Pseudomonas
Salmonella

** means important to know, it can kill if no spleen, but luckily those have vaccines

Question 4

What nonbacterial is encapsulated?

Answer 4

Cryptococcus is seen with india ink (soap bubbles in brain)

Question 5

What is transformation? who does it (leah?)

Answer 5

DNA lysed from cell and taken up by living bacteria and it is INCORPORATED into chromosomal DNA

SHiN
Strep pneumo
H influ
Neisseria m

Question 6

What are transposons?

Answer 6

Small segments of DNA that can relocate into different part of chromosome or to plasmid. Can carry resistance or virulence

Question 7

What is transduction? What virulence factors are gained by it?

Answer 7

Phage puts DNA into bacteria

Some bacterial DNA can be in package.

New phage injects bacterial viral ino DNA of next bacteria

ABCDE
shigA like toxin
Botulinum toxin (certain strains)
Cholera toxin
Diphtheria toxin
Erythrogenic toxin of Strep Pyo

Question 8

Mycoplasma vs mycobacteria?

Answer 8

Mycoplasma: no cell wall (need sterol)

Mycobacteria: have mycolic acid in cell wall and high lipid content

Question 9

What bacteria make spores?

Answer 9

Bacillus and clostridium (yeah, think C dif and Rice poisoning)

Question 10

What don’t gram stain?

Answer 10

These Microbes May Lack Real Color

Trepenoma (too thin)
Mycobacteria (high lipid content: acid fast)
Mycoplasma: no cell wall
Legionella (intracellular and weird branch, use silver stain)
Rickettsia (intracellular)
Chlamydia (intracellular)

Question 11

What is Giemsa stain?

Answer 11

(Certain Bugs Really Try my Patience)

Chlamydia, Borrelia, Rickettsaiae, trypanosomes, plasmodium

Question 12

PAS?

Answer 12

Stains glycogen to diagnose Whipple disease. Tropheryma whipple

PAS the sugar (whipple like whip cream)

Question 13

Ziehl-Neelson?

Answer 13

Acid fast organism (Ziehl Neelsen is fast)

Nocardia and mycobacterium

Question 14

India ink?

Answer 14

Cryptococcus

Question 15

Silver stain?

Answer 15

Fungi (pnuemocystis PCP), Legionella, H pylori

Question 16

What is toxic part of endotoxic? What 3 things does it activate?

Answer 16

lipid A of endotoxin (normally bound to the membrane of intact cells)

Activates Macrophage:
IL-1, 6 and TNF alpha (latter can cause cells death and cachexia), NO is released: shock

Activates complement:
C3a (histamine release, HTN/edema) and C5a neutrophil chemotaxis

Tissue factor: Coag and DIC

Question 17

Where do exotoxins come from?

Answer 17

Bacteria (usually G+), can have antigenicity (antibodies)

Question 18

What toxins affect neurotransmitters?

Answer 18

Tetanopasmin and botulinum toxin

Question 19

What are enterotoxins?

Answer 19

Shigella and vibrio cholera

Question 20

What are super antigen?

Answer 20

Bindto MHCII and TCR same time so IFN gamma and IL2 go nuts

Staph A TSST-1
Strep Pyo Exotoxin A

Question 21

What is streptolysin O and streptomycin S?

What is erythrogenic/porogenic toxin?

Answer 21

O is hemolysis (oxygen labile)
S is hemolysis (oxygen Stable)
Strep exotoxin causing rash and fever of scarlet fever

Question 22

What is diphtheria toxin? What is it similar to?

Answer 22

Adp ribosylation
Inactivates EF-2 so no protein synthesis

Cardiac and nerve cells!
Similar to Pseudomonas Exotoxin A

Question 23

Pseudomonas exotoxin is what? What is it similar to?

Answer 23

Elongation factor 2 is blocked so cells die b/c no proteins made

Similar to diphtheria

Question 24

What is shiga toxin? What does it do? What is it similar to?

Answer 24

Host rRNA at 60s subunit so no protein synthesis and kills cell.

Similar to E coli O157:H7 EHEC

Question 25

What makes EHEC so bad?

Answer 25

EHEC makes shiga like toxin (bloody diarrhea, the H in EHEC). Can cause Hemolytic Uerimic Syndrome: HUS.

HUS can cause: hemolytic anemia, thrombocytopenia, acute renal failure

Question 26

What does ETEC make?

Answer 26

Rice water diarrhea (as does cholera)

Heat labile: more cAMP so more Cl leaves gut (labile in Air)

Heat stabile makes more cGMP (stable on Ground) so less NaCl reabsorption

Causes Traveler’s diarrhea (T in ETEC)

Question 27

What does Yersinia entercolitica make?

Answer 27

It is similar to ETEC head stabile toxin (cGMP is higher)

Question 28

What does anthrax toxin do?

Answer 28

Mimics edema factor: adenylyl cyclase to make cAMP to cause edema

Lethal Factor not important care
Protective factor not important

Question 29

Cholera toxin does what?

Answer 29

Perminently turns on Gs to activate to make cAMP which causes Cl secretion out of the gut!!!!

Question 30

How does pertussis toxin work?

Answer 30

Disables Gi so can’t turn off cAMP reduction and can’t phagocytose

Question 31

Clostridium tetani does what?

Answer 31

blocks release of GABA and Glycine in inhibitory fibers and lock jaw

Question 32

What does botox do?

Answer 32

Exotoxins chop SNAREs at NM junctions and flaccid paralysis by blocking acetylcholine

(spoiled canned goods or honey)

Question 33

What does alpha toxin of clostridium per fringes do?

Answer 33

alpha toxin is phospholipase casues gas gangrene

Also makes enterotoxin after food has been out too long