Bacillus Flashcards
Name the two most important bacillus:
1) Bacillus anthracis
2) Bacillus cereus
Where does bacillus anthracis come from?
Animals - Zoonosis - but humans canbe infected with the spores.
Bacillus anthracis looks:
big, nonmotile and spore forming.
bacillus anthracis pathogenesis:
two major toxins:
1) poly-D-glutamic acid capsule - inhibits phagocytosis
2) The toxin complex comprising three proteins: the protective antigen (PA), edema factor (EF) and lethal factor (LF).
- Forms two pathogens: Oedema toxin (PA + EF) and lethal toxin (PA + LF)
- PA forms pore and LF or EF enters.
- Does different things when in cell. LF causes buld up of IL-1beta which when released causes shock and death.
- can happen basically anywhere and can also cause meningitis
LF
metalloprotease -inhibits MAPKK that causes IL-1 build up and TNF-alpha secretion
EF
Adenylate cyclase - makes cAMP disturbs processes.
Name the three anthrax clinical manifestations:
1) Cutaneous (skin)
2) Gastrointestinal
3) Inhalation
Cutaneous anthrax:
spore gets on skin - causes gradually more and more necrosis (wound gets bigger)
Inhalation anthrax:
dose about 25.000-55.000 - causes bleeding from multiplication of bacteria in macrophages in lungs and becomes systemic.
GI anthrax:
When you eat spores.
Injection anthrax
Heroin addicts and there are spores in the heroin.
Lab investigations:
swab cutanous (take some fluid - has higher yield.) Gram stain - big gram positive rods. PCR.
Treatment:
Skin = penicillin Inhalation = ciproflaxcin
Bacillus cereus:
Looks like B. anthracis but is motile, has no capsule and beta-haemolytic.
Bacillus cereus infection
Usually from environment - produces toxins - very common in rice and other chinese foods - causes immediate vomitting (within 6 hours) and later diarrhea (6-24 hours)