Exam 4: Gram + rods Flashcards
What are the two main groups of gram positive endospore forming rods?
- clostridium
- bacillus
What is a unique feature of all clostridium and bacillus bacteria?
- endospore forming
what bacteria causes food poisoning via two enterotoxins ( A which causes diarrhea, cramping and C which causes hemorrhagic enteritis) and exotoxin that destroys muscle and can cause gas gangrene
clostridium perfringens
What bacteria produces 7 neurotoxins that block cholinergic synapses, causing flaccid paralysis in adults and infants (AKA botulism)?
clostridium botulinum
How is botulism diagnosed in adults?
serum is injected into mice. if toxin is present, mice will begin to die within hours
How is botulism diagnosed in infants?
it can only be identified in bowel contents, not in serum
What bacteria produces neurotoxin that blocks inhibitory impulse to muscles resulting in spasm and sustained contraction?
clostridium tetani
What is it called when tetany causes spasm in back muscles such that the head is thrown back and back is arched like a bow?
opisthotonos
Greek: opisthotonos ‘drawn backward’
a severe infection of the colon by antibiotic resistant clostridium difficile bacteria, often after normal gut flora is eradicated by use of broad spectrum antibiotics
pseudomembranous colitis
Why are loperamide and bismuth contraindicated with clostridium difficile?
because the slowing of fecal transit time is thought to result in extended toxin-associated damage
Are any of the gram positive endospore forming rods part of the normal flora?
yes, clostridium difficile is present in normal flora of a minority of the population
What is the only bacteria that has a capsule composed of protein?
bacillus anthracis
How is the endospore of bacillus different from the endospore of clostridium?
the endospore of bacillus has a bamboo-like pattern
What causes wool sorters disease?
cutaneous anthrax - endospore of bacillus anthracis bacteria enters a wound
What is inhalation anthrax?
spores of bacillus anthracis are inhaled into alveoli, exsporulate, release toxins and cause nonspecific symptoms that are often fatal
What bacteria is a gram + endospore forming rod that is non-encapsulated, resistant to penicillins and produces two types of endotoxins (1. diarrheal, 2. vomiting)
bacillus cereus
What are the two gram +, non-endospore forming rods?
- corynebacterium diphtheriae
- listeria monocytogenes
What is the primary reservoir for corynebacterium diphtheriae?
humans
What bacteria produces a toxin that can cause paralysis of soft palate and eye muscles and can also be absorbed in the blood and cause distant toxic damage to kidneys, heart, extremity nerves?
corynebacterium diphtheriae
What is the diagnostic test for corynebacterium diphtheriae?
Schick test
What are the components of the DPT immunization?
diphtheria, pertussis, tetany
What bacterial infection is characterized by a whitish gray membrane of clotted blood, epithelial cell and leukocytes that forms in the throat and can detach to cause suffocation?
corynebacterium diphtheriae
What are some unique features of listeria monocytogene?
- it is motile at 22-28 degrees but not at body temp
- beta hemolytic
- produce endotoxin
What bacteria can cross the placental barrier resulting in miscarriage or delivery of critically ill neonate?
listeria monocytogenes
What demographic is most at risk for listeria monocytogenes?
immunocompromised and pregnant
Which bacteria are anaerobic? Clostridium or bacillus?
Clostridium
Which bacteria are aerobic? Clostridium or bacillus?
Bacillus
