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33 Cards in this Set
- Front
- Back
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What are the two clinically relevant species of bacillus?
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B. anthracis, B. cereus.
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Describe the structure of B. anthracis. .
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Gram positive, large rod-ilke bacillus.
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Describe the physiology of B. anthracis.
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non-motile, spore former, facultative anaerobe.
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What are the two plasmids present in B. anthracis?
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pX-01 and pX-02.
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What are the subunits of pX-01?
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Protective antigen (PA), Lethal factor (LF), and Edema factor (EF)
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What is the difference between LF and EF?
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LF causes death and EF causes swelling.
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How do the subunits/toxins of the plasmid pX-01 work?
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PA (protective antigen) enters via anthrax toxin receptor (ATR), which is present on all cells. LF or EF binds to the PA and enters the cell through receptor mediated endocytosis. Once internalized, the toxins are released into cytoplasm.
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What does the pX-02 plasmid encode for?
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polypeptide capsule. Unusual, most bacteria are made of polysaccharide capsules.
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Where do the anthrax spores survive?
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In the soil.
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What are the three disease types of anthrax in humans, from most common to lease common?
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Cutaneous, inhalational, gastrointestinal.
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How are most anthrax cases caused?
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By cutaneous contact with herbivores.
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What is believed to have been the fifth plague mentioned by Moses in the bible?
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Anthrax.
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Why would anthrax make a good bioweapon?
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Available, easy to produce in large quantities, very stable in dried form, widespread transmission is possible.
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What happened in the Sverdlovsk accident?
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In former Soviet Union, a small amount was released accidentally all over the city. 77 cases confirmed and 66 deaths. Anthrax cases from up to 50 km away from incident.
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What happened in the 2001 US anthrax attack?
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22 people infected, 11 inhalational, 11 cutaneous. 5 with inhalational died.
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What is the incubation period for cutaneous anthrax?
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1-12 days?
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What does the infection look like in the beginning and the end for cutaneous anthrax?
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Begins as a papule or small raised lesion and developes into a large necrotic lesion with a characteristic black eschar (Black scar)
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What are the two syndromes of gastrointestinal anthrax?
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Oropharyngeal, intestinal.
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What percentage of people die from gastrointestinal anthrax?
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25-60%
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What is the incubation period of inhalational antrhax?
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Incubation can be less than two weeks or more than two months. Rapid progression from first symptoms to death.
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What is the mortality rate of inhalational anthrax?
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up to 85%
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What are some of the symptoms of inhalational anthrax?
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Fever, edema, enlargement of mediastinal lymph nodes, blood pleural emissions,
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How do you treat inhalation anthrax?
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Ciproflaxin.
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How do you prevent inhalation anthrax?
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Human vaccinations which are reserved for people only at extremely high risk.
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Describe the structure of B. cereus.
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Gram positive bacillus. Rod-shaped. Motile. No capsule. Forms spores.
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Describe the physiology of B. cereus.
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Spore former and facultative anaerobe.
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How does B. cereus cause disease?
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Food poisoning, toxin production.
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What are the two different toxins produced by B. cereus?
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Emetic toxin and enterotoxin.
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What is the difference between emetic toxins and enterotoxins?
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Emetic toxins are heat stable, acid stable, and causes emetic (vomiting) disease. Enterotoxins are heat sensitive, acid sensitive, and causes diarrhea.
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Describe the epidemiology of B. cereus.
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Transient part of fecal flora, and is found pretty much everywhere. Soils, vegetables, rice, meat.
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Describe the emetic disease associated with B. cereus.
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Associated with rice. 6 h of incubation. Heat stable, can survive reheating. Induces vomitting. Spores germinate and produce emetic toxin during storage. Preformed toxin is ingested.
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Describe the diarrheal disease associated with B. cereus.
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Causes diarrhea, after 12 hours of incubation, associated with meat and vegetables. Spores survive cooking, Spores are then ingested, the toxin is then produced in the small intestine.
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How do you treat B. cereus?
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Antibiotics are ineffective against food poisoning. Ciproflaxin is prescribed when necessary, but not helpful with any emetic disease. Don't reheat rice after leaving it out at room temperature!
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