18.2 - C.tetani Flashcards
tetanus neurotoxin aka?
tetanospasmin
difference between tetanus and botulism toxin
site of action:
tetanus = CNS: blocks glycine/GABA release
Botulism = motor neurons release of ACh
how many serotypes of tetanus toxin
one (botulism has ~7)
what is mechanism of tetanus toxin? how different from botulism?
same MOA: (two chains) zinc endopeptidase degrades synaptobrevin (a SNARE protein) on glycine-containing vesicles
Difference is site of action only
How many toxins does tetanus produce? and what class are they
2
neurotoxin
hemolysin (tetanolysin) = Beta hemolysis –> kills phagocytic cells and other tissue
how is tetanus transmitted
wounds fromsoil containing spores
what are 2 populations that are most susceptible to teatanus and why
older women: less adequately vaccinated
Diabetics: ???
what type of wounds are more likely to produce a tetanus infx and why
minor wounds bc major wounds are better managed
how does tetanus toxin travel? how is this different than botulism
via retrograde axonal transport
botulism travels in bloodstream
what is trismus
lock-jaw
difference in muscle effects between tetanus and botulism
tetanus = spastic/rigid paralysis; opisthotonic back and neck bending
botulism = flaccid
how does tetanus and botulism kill
respiratory paralysis
dx of tetanus
CP and history of puncture wound (may look insignificant)
active tx of tetanus (2) infx and MOA
metronidazole or penicillin G - stop any further growth and toxin release
passive immunization approach with tetanus (and MOA)
antitoxin (human tetanus immunoglobulin)
in order to neutralize free toxin in the tissue before transport.
Which is given immediately in a tetanus infx
antitoxin (human tetanus immunoglobulin)
in order to neutralize free toxin in the tissue before transport.
active immunization is achieved via what
tetanus toxoid
When is the DTaP given (3) and what is the tetanus component composed of?
2, 4, 6 months
tetanus toxoid
When is the DTaP booster given (2)?
15-18 months and 4-6 years
when is the toxoid booster Tdap given in each of 3 populations
-11-16 years to used to boost for pertussis (and tetanus)
- any age that hasn’t had pertusis booster
pregnant women (to protect newborn)
when is the Td booster given
every 10 years after age 16 I guess
Why is the booster given?
can’t rely on memory cells - need to maintain circulating antibody
minor and major wound respectively: how do you tx patients with 3 or more toxoid doses (childhood immunizations)
major wounds: toxoid if >5 years since last booster (you’re giving them their 10-yr booster early to increase the circulating Ab)
minor superficial wounds: toxoid only if >10 years since last booster (you’re giving them the booster they have missed)
minor and major wound respectively: how do you tx patients with < 3 or unknown number of prior toxoid doses (unknown immune status)
minor superficial wounds: toxoid
major wounds: toxoid plus tetanus immune globulin (anti-toxin)
