Bailey- Clostridia Flashcards
Clostridium is strictly _______ and can produce what when environmental conditions are not favorable?
strictly anaerobic
can produce endospores
what type of toxins are produced by clostridium that causes disease symptoms?
Proteinaceous (protein based) toxins
T/F: Few bacteria have the ability to form endospores
True
when in spore form, an organism can remain viable for how long?
hundreds of years
what is the opposite of the spore stage of a bacteria?
vegetative stage
T/F: Clostridium difficile got its name because it was difficult to culture?
true
Pseudomembranous colitis (PMC) are yellow plaques containing what? Where are they found?
fibrin and cellular debris. found in ulcers of the colon
-from C. difficile
what organism is the leading cause of nosocomial (hospital related) diarrhea?
C. difficile
C. difficile is often harbored in a dormant state in the ___ _____ of a small % of healthy humans
large intestine
what happens when C. difficile enters its vegetative state?
- toxin production begins. results in diarrhea.
- invasion of bowel wall does not occur
C. difficile does not invade the bowel wall….. which other bacteria share this characteristic?
E. coli and V. cholerae
C. difficile produces Toxin A, a ______, as well as Toxin B, a _____
Toxin A - enterotoxin
Toxin B- cytotoxin
both Toxin A and B act in the cytoplasm of host cell to _______ GTP-binding proteins
glycosylate
-cells lose structure and die
C. perfringens is a major pathogen of what?
wound infections
C. perfringens has invasive properies due to a variety of _____
toxins produced
C. perfringens must have what conditions to germinate in human tissue?
- anaerobic
- compromised blood supply
- calcium ions
- available peptides and AA’s
Toxins produced by C. perfringens cause cellulitis, which can turn into what?
gas gangrene- necrotizing, gas forming process of muscle
C. perfringens produces 12 toxins, the main one being _______
Alpha-toxin (lecithinase)
what does the Alpha-toxin of C. perfringens do?
damages cell membrane
-causes gas gangrene
treatment of C. perfringens infection
A) surgical removal of infected muscle
B) antibiotics to control infection
C. perfringens sporulate, producing ______ in intestines of people consuming contaminated food
enterotoxins
cause food poisoning
T/F: food poisoning from perfringens requires immediate antibiotic treatment
false- its self limiting and disappears in 1-3 days
Clostridium botulinum forms heat-resistant ______, and is the causative agent of what illness?
heat-resistant spores
causes botulism
T/F: botulism is caused by pre-formed toxin, meaning the organism does not need to be present
true
C. botulinum produces _______, named BoNT
neurotoxins
BoNT from C. botulinum prevents the release of what neurotransmitter?
acytylcholine
death from BoNT results from what?
flaccid paralysis (respiratory failure)
what are the 3 forms of botulism?
1) food-borne
2) wound botulism (rare)
3) infant botulism
why are no antibiotics necessary when treating C. botulinum?
the toxins are preformed, meaning that killing the bacteria would not effect the course of the illness
Clostridium tetani is ubiquitous in the _____ of humans and animals
GI tract
Germination of C. tetani spores triggers the production of what major toxin?
tetanospasmin
T/F: tetanospasmin is made up of 2 toxic chains linked together
false- individual chains are non-toxic
tetanospasmin from C. tetani attaches to _______ nerves and inhibits _____ release
peripheral nerves
inhibits GABA release
by inhibiting GABA, tetanospasmin poisoning results in what?
reflex spasms, spastic paralysis
what is Trismus? what is it caused by?
Trismus- “lockjaw”
tetanic spasm of masseter muscles
leads to respiratory failure from paralysis of chest muscles
illness from C. tetani is preventable by giving a ____ vacine
DPT vaccine
the “T” of DPT stands for tetanus toxoid
T/F: antibodies are produced after initial exposure to tetanospasmin toxin
False- toxin is in too low of an amount to form antibodies
what causes pseudomembranous colitis? which bacterial species is responsible?
-condition forms after antibiotics. allows C. difficile to flourish when normal bacteria are killed (it hides in its spore form)
