Exam 4 Flashcards
C. diph grows on…
blood
Loeffler slant
C. diph shows blackening with…
tellurite
C diph characteristics
GP
rod/club
non-spore
Pleimorphic
take V/L/Y-shaped arrangements of 2 bacteria or more
pleimorphic bacteria
C. diph
granules unique to C diph
Metachromatic (volutin) granules
stores of polyphosphage (excess phosphorus)
bluish/brownish lumps
staining used for C diph
albert staining
Loeffler grows…
contains….
C. diph
protein and fat
diphtheria transmitted by…
aerosol droplet
diphtheria presentation
malaise, low-grade fever, sore throat, loss of appetite
Pseudomembrane
pseudomembrane
buildup of fibrin, bacteria, and dead WBCs - forms in back of throat - cannot be scraped away, embedded in tissue
diphtheria vaccine contains…
Vaccine consists of heat-treated B fragment toxoid
necessary to make DT
lysogenization with corynebacteriophage
genome for C diph normally contains a —— that blocks —–
normally produces a DtxR regulator that blocks the toxin gene tox
iron involvement in DT
Iron is a corepressor - when present, it binds apo-DtxR, which sits on operator for tox
if Iron is absent, DT is made
DT:
———- of component — binds ——-, which is found on many tissues, including heart and nervous
triggers……
Domain R of component B binds Heparin-Binding Epidermal Growth Factor (HB-EGF), which is found on many tissues, including heart and nervous - triggers uptake via endosomification
DT:
Upon acidification of the endosome, the ——– of component — triggers insertion of toxin through endosomal membrane
disulfide bridge is reduced, and component —- is released
Upon acidification of the endosome, the T domain of component B triggers insertion of toxin through endosomal membrane - disulfide bridge is reduced, and component A is released
action of DT
DT acts by ADP-ribosylation of Elongation Factor 2 (EF-2)
adenine from NAD+ is attached to residue
this inactivates EF-2, and if enough are inactivated, protein synthesis stops, and the cell dies
special amino acid involved in DT
diphthamide
modified histidine
C. bot grows on…
Willis-hobbs medium
includes peptone, meat extract, lactose, egg yolk, skim milk
C. bot characteristics
GP, spore-forming, rod-shaped
tennis-racket shape caused by spores
staining for C. bot
Endospores are stained with malachite green, and vegatative cells stain with safranin
C. bot causes…..
not infection
intoxication
inactivates BoNT
heat
BoNT attacks….
attacks neuromuscular junctions and autonomic synapses
botulism presentation
generalized flaccid paralysis, n/v, double vision, h/a, slurred speech
tx for botulism
neutralizing antitoxin administered quickly
explain infant botulism
microbiota can’t outcompete C. bot
spores from honey germinate in LI
paralytic sx, constipation
tx is baby immunoglobulin
explain wound botulism
Killer of soldiers
Anaerobic pockets in deep wounds
Spores germinate, and toxin enters bloodstream
Encourage bleeding in deep/puncture wounds to wash out spores
present on ACh vesicles in axon terminal
synaptotagmin (syt)
synaptobrevin (VAMP)
anchor ACh vesicle to the membrane at the axon terminal
Syntaxin
SNAP25
complexin
—– part of BoNT makes it into bloodstream
derivative
light chains of BoNT are ———–,
which degrade….
metalloproteinases
VAMP, syntaxin, and SNAP25
ultimate effect of BoNT on NMJ
prevention of ACh release
C. tet characteristics
GP, spore-forming, rod-shaped
C. tet causes (infection/intoxication)
infection
high doses of TeNT
C. tet transmission
deep puncture wounds
anoxic pockets in flesh
in common between BoNT and TeNT
Both code for zinc-requiring endopeptidases
Both cleave VAMP
location of effects of TeNT in high doses
CNS
affects inhibitory neurons
ultimate effect of TeNT on NMJ
blocks release of glycine and gamma-aminobutyric acid
