Clostridium-Bacillus - Exam III Flashcards
Describe the gram stain and shape of clostridium:
Gram positive rods
A major virulence factor of clostridium is that:
they are endospore forming
Describe the oxygen requirements of clostridium and spores:
obligate anaerobes; spores are O2 resistant
Where can clostridium be encountered?
Environment (soil) and intestinal mucus
How can we detect spores of clostridium?
Endospores stain hot malachite green
Endospore staining is also used for:
aerobic endospore formers like gram + bacillus
Describe the virulence factors of clostridium:
spore formation
The spores of clostridium contribute to virulence because:
- resistant to destruction
- resistant to sterilization
- resistant to antibiotics
How might we remove clostridium spores from a medical device?
autoclave (heat under pressure- boiling is not effective)
When the disease causing component is solely due to the toxin, this is referred to as:
intoxication
The type of clostridium that gives rise to a severe form of food poisoning leading to paralysis
clostridium botulinum
In addition to food ingestion, clostridium botulinum may cause botulism by:
soil or fecal contamination
_____ is possible from soil or fecal contamination:
wound botulism
Explain how infant botulism occurs:
Because of lack of full development of intestinal flora, if clostridium botulinum is introduced to infant between 3-20 weeks, it has the capability of rapid overgrowth
Describe the effects of infant botulism:
muscle weakness; rarely paralysis
How does infant botulism resolve?
normally resolves as intestinal flora develops
Describe the virulence factors of clostridium botulinum:
Botulinum neurotoxin (AB-exotoxin) blocks acetylcholine release
What does botulinum neurotoxin (AB-exotoxin) block and what does this cause?
acetylcholine; flaccid muscles–> paralysis
Because clostridium botulinum does not _____, it acts through ____.
invade tissues; toxins
The spores of clostridium botulinum are ____, while the botulinum toxin is ____.
heat-stable; heat-labile
How long does anti-toxin neutralization to the botulinum toxin take to work?
weeks to months
The form of clostridium that is typically caused by dirty, puncture wounds (knife, bullet, tattoo) that are typical opportunities for the anaerobic growth of this bacteria:
Clostridium tetani
Describe the oxygen requirements for clostridium tetani:
anaerobic
Bacterial growth of clostridium tetani remains ___ but the tetanus toxin ___.
localized; spreads
What toxin is responsible for the virulence of clostridium tetani:
tetanospasmin
Describe tetanospasmin:
tetanus AB-exotoxin neurotoxin; plasmid-encoded
Describe the mechanism of action of tetanospasmin:
blocks GABA and glycine release; leads to loss of inhibitory input to motor neuron excitation leading to spastic paralysis
In clostridium tetani, the spastic paralysis is due to:
uncontrolled muscle contraction from tetanospasmin
The effects of tetanospasmin may be:
localized and one-sided (on opposite side of infection)
Describe the effects of anti-toxin on tetanospasmin:
usually too late for anti-toxin treatment
clostridium tetani does not ____ so it acts through ____.
invade tissue; toxins
A dramatically deadly disease characterized by the inability of muscle relaxation:
tetanus
Tetanus toxin prevents:
muscle relaxation
Infection with tetanus systemically can cause:
- cardiac arrhythmias
- blood pressure swings
- dehydration