Bacillus Flashcards
Physical description of Bacillus
- G positive
- chains, palisades, clumps
- sporulating
- aerobic
- soil and leaves
Description of Bacillus cereus
- acute food poisoning
- subterminal spores
- large, flat, rough, colonies
- NOT zoonosis
Clinical presentation of B. cereus
- emetic variety; very acute, nausea, vomiting, cramps
- diarrheal variety; slow, profuse diarrhea, cramps, no vomiting
Where is Bacillus cereus acquired
- cooked rice and pasta that has been cooled too slowly
- spores now germinate and produce toxin
Description of the toxin
- emetic toxin; K+ ionophore
- 3 enterotoxins; hemolytic, nonhemolytic(pore former), cytotoxin(activates adyl. cyclase)
Description of Bacillus anthracis
- anthrax
- central spores
- cut glass rough colonies
- poly D glutamate capsule
Clinical presentation of Bacillus anthracis
- papule becomes large necrotic eschar
- disseminates and becomes systemic
Epidemiology of Bacillus anthracis
- animals ingest spores from soil
- spores viable in soil for many years
- human infection from handling infected animals materials
- spores contact mucous membranes
- inhaled or ingested
Action of spores of bacillus anthracis
- enter macrophages and germinate within phagolysosome
- activated by the O2 radicals
Description of the toxin of bacillus anthracis
- tripartite AB type toxin, plasmid encoded
- B is binding, protective antigen binds to receptor
- A; lethal, MAPK protease; edema, calmodulin dependent adenyl cyclase, so makes cAMP and secretion of water into tissue, edema
Restriction of virulence for bacillus anthracis
-both plasmid for capsule and toxins; pXO2(capsule) and pXO1(toxin)
Control of bacillus anthracis
-penicillin(cutaneous), doxycycline, ciprofloxacin
