Microbiology - chapter 6 - Bacillus and Clostridium Flashcards
Name the two species of pathogenic spore-forming, gram positive aerobic rods?
Bacillus anthracis - causing anthrax
Bacillus Cereus - causing gastroenteritis
Pair em’ up correctly:
Bacillus - Aerobic
Clostridium - Anaerobic
They are paired up correctly ;)
Bacillus anthracis is the only bacterium with ………. ?
capsule composed of protein(poly-D-glutamic acid)
What regulates the virulence fators pXO1 and pXO2 plasmids in bacillus anthracis?
- increase in temperature to 37 degrees
- carbondioxide concentration
- serum proteins
What is the most common route of entry for bacillus anthracis?
skin = cutaneous anthrax infection.
Where, in pulmonary anthrax, do the spores germinate?
They are transported from the lungs to the hilar lymphnodes by macrophages, where they germinate.
What toxins are the bacillus anthracis plasmid pXO1 coding for?
1 Edema factor(EF) - increases cAMP levels, impair neutrophils, cause edema.
2 Protective antigen(PA) - promotes EF entry into cells.
3 Lethal factor(LF) - zinc metalloproteinase that inactivates protein kinase.
What is the bacillus anthracis plasmid pXO2 coding for?
It encodes three genes necessary for the synthesis of a poly-glutamyl capsule.
motile, non-encapsulated penicillin resistant bacillus?
Bacillus cereus
Bacillus cereus codes for two enterotoxins that cause two types of food poisoning, what are they?
1 A heat-labile toxin: causes nausea, abdominal pain and diarrhea
2 A heat-stable toxin: severe nausea and vomiting, limited diarrhea
Anaerobic organism responsible for causing botulism, tetanus, gas gangrene and pseudomembranous colitis?
Clostridius.
Clostridium botulinum, pathomechanism?
Potent neurotoxin that blocks ACh release from presynaptic nerveterminals in autonomic nervous system and motor endplates.
Tetanospasmin, pathomechanism?
toxin produced by clostridium tetani. Tetanospasmin acts on the inhibitory Renshaw cell interneurons preventing the release of GABA and glycine, which are inhibitory nurotransmitters. This inhibition of inhibitory neurons causes tetanus
risus sardonicus?
grotesque grinning expression due to tetanous cotraction of the facial muscles
Three main groups of patients with skin wounds that exhibit tetanus?
Patients that:
1 had their last shot of vaccine more than ten years ago.
2 never have been immunized.
3 already have developed tetanus
