Gram positive endospore forming rods Flashcards
Identify the relevant risk factors associated with Clostridium botulinum.
improperly reheated food
honey given to infants
An infant eats honey and becomes flaccid. Organism? Mechanism?
Clostridium botulinum
inhibited release of ACh
Name the bacteria associated with food poisoning from reheating meat dishes.
C. perfringens
What is the major reservoir for Clostridium difficile?
4% of general population are carriers
ubiquitous in hospitals
Identify the major virulence/toxicity factors associated with Bacillus anthracis.
exotoxin
antiphagocytic polypeptide capsule
How is Bacillus anthracis transmitted?
spores in infected animals or animal products (furs, bones, etc.) can contaminate wounds or mucous membranes or be ingested or inhaled
T/F: C. perfringens produces alpha-toxin, a globulin that causes myonecrosis, gas gangrene, and hemolysis.
false
alpha-toxin is a lecithinase
What is pathognomonic or the most common association with Clostridium difficile?
extremely antibiotic resistant
1/3 of all diarrhea in patients who are taking antibiotics are caused by this organism
Identify the major virulence/toxicity factors associated with Bacillus cereus.
spores not killed by boiling
emetic toxin
diarrheal toxin
What is the major reservoir for Clostridium botulinum?
soil, pond, lake sediments
What procedures or lab findings are useful to help diagnose Clostridium difficile?
endoscopy
detection of toxins in stool
What is the morphology of Bacillus cereus?
endospore forming rod
How does Bacillus anthracis gram stain?
positive
How does Bacillus cereus gram stain?
positive
What lab findings are useful to help diagnose Clostridium perfringens?
gram + rod
double zone of hemolysis on blood agar (anaerobic conditions)
lecithinase +
Identify the major virulence/toxicity factors associated with Clostridium botulinum.
seven distinct neurotoxins which prevents release of ACh, resulting in flaccid paralysis
Identify relevant epidemiology and risk factors associated with Clostridium difficile.
dysbiosis following antibiotic therapy
What is the morphology of Clostridium difficile?
endospore forming rod
What lab findings are useful to help diagnose Clostridium tetani?
organisms are not cultured and the exotoxin is extremely potent at very low doses
What lab findings are useful to help diagnose Bacillus anthracis?
large, boxcar like, spore-forming rods
gram +
aerobic
Identify the major virulence/toxicity factors associated with Clostridium tetani.
the potent exotoxin tetanospasmin blocks GABA and glycine release in CNS leading to spastic paralysis and death
What lab findings are useful to help diagnose Clostridium botulinum?
since the toxin creates disease and not the organism, lab tests are impractical
What are the clinical manifestations of Clostridium tetani?
tetanus - spastic paralysis days to weeks after initial exposure with the masseter muscle often the first to show symptoms
Describe the characteristic lesion of anthrax.
black skin lesions - vesicular papules covered by black eschar
How is Clostridium tetani transmitted?
through a penetrating injury, often a nail or a needle
How does Clostridium tetani gram stain?
+
Name the bacteria associated with food poisoning from improperly canned food.
C. botulinum
What causes pseudomembranous colitis?
cytotoxin, an alpha toxin produced by C. difficile, usually after antibiotic use
What are the clinical manifestations of Clostridium botulinum?
botulism - nausea, cramps, vomiting and diarrhea or constipation 18-36 hrs after ingestion
descending flaccid paralysis begins in head, can result in respiratory failure if it reaches lungs
What is the major reservoir for Clostridium perfringens?
spores are found in soil, air, and water
What are the clinical manifestations of Clostridium difficile?
antibiotic associated diarrhea - usually self-limiting
pseudomembranous colitis - hemorrhagic diarrhea, colitis, pseudomembrane
What is the pathognomonic association with Bacillus cereus?
symptoms of food poisoning following ingestion of reheated rice
What are the clinical manifestations of Clostridium perfringens?
gas gangrene
food poisoning (nausea, abd. pain, diarrhea, vomiting/fever rare) 8-24 hrs after eating w/ recovery after 24 hrs
Identify the major virulence/toxicity factors associated with Clostridium difficile.
toxin A is cholera-like enterotoxin
toxin B is a diptheria-like cytotoxin
How is Bacillus cereus transmitted?
eating spore contaminated food
How does Clostridium botulinum gram stain?
+
What is the morphology of Clostridium botulinum?
endospore forming rod
What are the clinical manifestations of Bacillus anthracis?
cutaneous, pulmonary, and gastroenteric anthrax
What is the morphology of Clostridium tetani? What real world object do they resemble?
endospore forming rod
“tennis racket” appearance
What are the clinical manifestations of Bacillus cereus?
if toxin pre-formed before ingestion, Staph. aureus like food poisoning
if spores ingested C. perfringens like food poisoning
What is the morphology of Clostridium perfringens?
endospore forming rod
What is the major reservoir for Clostridium tetani?
soil
What are the major reservoirs for Bacillus anthracis?
animals, animal skin, fur products, soils
What is the morphology of Bacillus anthracis?
endospore forming rod
How is Clostridium perfringens transmitted?
ingestion of contaminated food
What is the major reservoir for Bacillus cereus?
found widely in nature
How does Clostridium perfringens gram stain?
+
Identify the major virulence/toxicity factors associated with Clostridium perfringens.
enterotoxin acts on small intestine
lecithinase can destroy virtually any cell of the body it comes across
other enzymes ferment muscle tissue, producing gas crepitations
How does Clostridium difficile gram stain?
+
How is Clostridium botulinum transmitted?
ingested, absorbed through the gut and carried by blood to peripheral nerves
