Question
A 10 yr old child presents to the ER with C/O bloody diarrhea, abdominal pain and decreased urine output. There is no H/O fever. Patient gives H/O consuming ground beef. Investigations revealed the following:-
– Stool examination – plenty of leukocytes.
– Stool culture-sorbitol Mac Conkey agar culture shows pale colonies.
– Faecal toxin was detected by ELISA
What is the most important mechanism responsible for patient’s condition?
| A. |
Plasmid coded antigen called virulence marker antigen( VMA )
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| B. |
Attachment mediated by fimbrial protein called colonisation factor antigen.
|
| C. |
Shiga-like toxin
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| D. |
Production of yeast 1 toxin
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Show Answer
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Correct Answer � C
Explanation
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|
Shiga-like toxin
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Inhibits protein synthesis by inhibiting 28S sub units of 60S ribosomes.
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Shiga-like toxin effects endothelial cells causing capillary microangiopathy which leads to hemorrhagic colitis and haemorrhagic uremic syndrome( HUS ).
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HUS is characterised by injury to small vessels of kidney and brain which lead to bloody diarrhea, renal failure and encephalopathy.
Other options explanation:
A)Plasmid coded antigen called virulence marker antigen( VMA ) – enteroinvasive E.coli is toxigenic but invasive.
B)Attachment mediated by fembrial protein called colonisation factor antigen – enterotoxigenic E.coli ( ETEC ) is a most common cause of traveler’s diarrhea. Pathogenesis of ETEC is by attachment to intestinal mucosa by colonisation factor
D Production yeast 1 toxin – enteroaggregative E.coli ( EAEC ). The pathogenesis is mediated by aggregative adhesion fimbriae 1 and yeast 1 toxin.
