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27 Cards in this Set
- Front
- Back
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which type of toxins are normally preformed?
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neurotoxins (--> immediate infection) N/V/D
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features of neurotoxins in GI
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stimulate receptors --> secretory diarrhea
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which common bacteria produce neurotoxins
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Staph aureus
C. botulinum |
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which bacteria produce enterotxins
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cholera
some strands of E. coli |
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how does cholera toxin --> dz
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subunit B binds gangliosides on epi cell membrane, releases toxic A2 substance
stim cAMP and fluid secretion |
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which E. coli toxin is similar to cholera toxin
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heat labile (LT) toxin
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how does heat stable toxin work in E. coli
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activates cGMP and stimulates NaCl absorption and Cl secretion
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what are the 3 main types of enteric infx?
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non-inflammatory
inflammatory invasive |
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how is infx caused in noninflammatory GI dz?
clinical features of dz location stool exam |
superficial invasion or attachment
watery diarrhea, might have n/v, pain fever small bowel no PMNL |
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inflammatory GI dz- clinical features
location stool exam |
dysentery w blood, mucous, small volume diarrhea, fever, can have systemic toxicity
colon moderate # of polys |
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how is infx caused in systemic GI dz?
clinical features of dz location stool exam |
penetration through mucosa to regional nodes and beyond
enteric fever, mild diarrhea, or no sx distal small bowel non-specific |
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examples of noninflammatory orgs
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cholera
c. perfringens ETEC norovirus |
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ex of inflammatory orgs
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Shigella
salmonella enteritidis c. diff e. histolytica |
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ex of systemic org
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salmonella typhii
y. enterocolitica |
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when should a stool exam be done
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only if + for WBC
immunocompromised, elderly, prolonged diarrhea |
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what in stool sample indicates inflammatory diarrhea
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polys in stool
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when is endoscopy done to evaluate GI infx
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in immunocompromised pts
dx c. diffpseudomembranous colitis |
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sx of GI staph aureus
toxin (preformed?) time to onset duration of sx |
vomiting, diarrhea, abdominal cramps
preformed 1-6 hrs 24-48 hrs |
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sx of norovirus
time to onset duration of sx inflammatory? |
abrupt onset of N/V, watery diarrea, cramps, sometmes fever
24-48 hrs (takes time to get to high levels) 48-72 hrs noninflammatory |
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sx of ETEC
time to onset duration of sx |
anorexia, cramps, explosive diarrhea, no blood or mucous in stool
4-14 days of arrival 1-5 days |
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when should stool culture be done in ETEC
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if no response to ABx
evidence of colitis look for parasites |
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sx of C. enteritis
toxin (preformed?) time to onset |
watery, bloody or minimal dairrhea, cramps
1-6 wks of ABx use |
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toxins in C diff
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toxin A and B --> mucosal injury
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clinical course of typhoid fever
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feer develops in 1-3 weeks following ingestion
occurs when org has spread beyond regional LN in Peyer's patches fever, abdominal pain, hepatosplenomegaly altered MS rash and pneumonia |
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dx of typhoid fever?
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stool cultures can be -, but blood and bone cultures usually +
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complications of typhoid fever
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intestinal perforation
bleeding hepatitis |
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in small bowel diarrhea, is glucose transport intact?
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yes, so if glucose and salt solution are made, water can be absorbed
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