Lecture 11 Flashcards
what are some traits of bacillus anthracis?
aerobic, gram positive, long and thin
what are the 2 forms of anthracis?
spores and vegetative state
what are some characteristics of spores?
- formed upon exposure to O2
- infectious form and hardy
- dont divide, no measurable metabolism
how does the vegetative state happen?
- spores taken up by macrophages and taken to lymph nodes
2. spores germinate and enter the vegetative state
once anthracis enters the vegetative state, whats next in infection?
- while in macrophages, spores lyse through and overwhelm lymph node
- infection gets in bloodstream
- in late stages animals bleed through nose, mouth, and bowel
- blood and corpse of animal exposed to more O2 creates more spores for cycle to repeat
what traits make spores hardy?
- resistant to drying, boiling less than 10 minutes, UV light and gamma radiation
- survive in soil for years
- still viable for decades in permafrost
what factors make soil favorable for spores?
- high moisture
- organic content
- alkaline (basic) pH
- high calcium concentration
what are the three kinds of anthrax?
cutaneous, gastrointestinal, and inhalational
how is inhalational anthrax transmitted?
- handling hides/skin of infected animals
- microbio lab
- intentional aerosol release
- small volume powdered form
how is cutaenous anthrax transmitted?
- handling hides/skins of infected animals
- bites from bugs
- handling powdered form
- aerosol release
how is gastrointestinal anthrax transmitted?
- ingestion of meat from infected animal
- ingestion of contaminated food
- ingestion from powder contaminated hands
which form of anthrax would least likely infect on a large scale?
Gastrointestinal because the acidity in the stomach is too strong for the spores
what are the three phases of inhalational anthrax and how long does each last?
- asymptomatic period (2-43 days)
- prodromal phase (hours-about 3 days)
- fulminant phase (about 3 days)
what are some traits of prodromal phase?
- correlates with germination and toxin production
- nonspecific flu like symptoms
- lasts several hours to days
- can have transient resolution before next phase
what are some traits of fulminant phase?
- correlates with high grade bacteremia/toxemia
- critically ill
- 50% develop hemorrhagic meningitis
- usually progresses to death
what are the most common areas of exposure for cutaneous anthrax?
hands, arms, neck, head