DIT Micro Basics and Toxins Flashcards
Lipotechoic acid is from where and elicits what?
G+ and can cause acute phase cytokine release
IL-1
IL-6
TNF alpha
What is glycocalyx? What does it do? How is it different than fimbria?
Mediates adherance to surfaces (especially cathetes) polysaccharide
Fimbria binds to other cells and is glycoprotein
What is a quelling reaction? What has positive reaction?
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
What nonbacterial is encapsulated?
Cryptococcus is seen with india ink (soap bubbles in brain)
What is transformation? who does it (leah?)
DNA lysed from cell and taken up by living bacteria and it is INCORPORATED into chromosomal DNA
SHiN
Strep pneumo
H influ
Neisseria m
What are transposons?
Small segments of DNA that can relocate into different part of chromosome or to plasmid. Can carry resistance or virulence
What is transduction? What virulence factors are gained by it?
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
Mycoplasma vs mycobacteria?
Mycoplasma: no cell wall (need sterol)
Mycobacteria: have mycolic acid in cell wall and high lipid content
What bacteria make spores?
Bacillus and clostridium (yeah, think C dif and Rice poisoning)
What don’t gram stain?
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)
What is Giemsa stain?
(Certain Bugs Really Try my Patience)
Chlamydia, Borrelia, Rickettsaiae, trypanosomes, plasmodium
PAS?
Stains glycogen to diagnose Whipple disease. Tropheryma whipple
PAS the sugar (whipple like whip cream)
Ziehl-Neelson?
Acid fast organism (Ziehl Neelsen is fast)
Nocardia and mycobacterium
India ink?
Cryptococcus
Silver stain?
Fungi (pnuemocystis PCP), Legionella, H pylori
What is toxic part of endotoxic? What 3 things does it activate?
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
Where do exotoxins come from?
Bacteria (usually G+), can have antigenicity (antibodies)
What toxins affect neurotransmitters?
Tetanopasmin and botulinum toxin
What are enterotoxins?
Shigella and vibrio cholera
What are super antigen?
Bindto MHCII and TCR same time so IFN gamma and IL2 go nuts
Staph A TSST-1
Strep Pyo Exotoxin A
What is streptolysin O and streptomycin S?
What is erythrogenic/porogenic toxin?
O is hemolysis (oxygen labile)
S is hemolysis (oxygen Stable)
Strep exotoxin causing rash and fever of scarlet fever
What is diphtheria toxin? What is it similar to?
Adp ribosylation
Inactivates EF-2 so no protein synthesis
Cardiac and nerve cells!
Similar to Pseudomonas Exotoxin A
Pseudomonas exotoxin is what? What is it similar to?
Elongation factor 2 is blocked so cells die b/c no proteins made
Similar to diphtheria
What is shiga toxin? What does it do? What is it similar to?
Host rRNA at 60s subunit so no protein synthesis and kills cell.
Similar to E coli O157:H7 EHEC
What makes EHEC so bad?
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
What does ETEC make?
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)
What does Yersinia entercolitica make?
It is similar to ETEC head stabile toxin (cGMP is higher)
What does anthrax toxin do?
Mimics edema factor: adenylyl cyclase to make cAMP to cause edema
Lethal Factor not important care
Protective factor not important
Cholera toxin does what?
Perminently turns on Gs to activate to make cAMP which causes Cl secretion out of the gut!!!!
How does pertussis toxin work?
Disables Gi so can’t turn off cAMP reduction and can’t phagocytose
Clostridium tetani does what?
blocks release of GABA and Glycine in inhibitory fibers and lock jaw
What does botox do?
Exotoxins chop SNAREs at NM junctions and flaccid paralysis by blocking acetylcholine
(spoiled canned goods or honey)
What does alpha toxin of clostridium per fringes do?
alpha toxin is phospholipase casues gas gangrene
Also makes enterotoxin after food has been out too long
