Lecture 20 Flashcards
(16 cards)
What are the anatomical features of the GI tract?
Long tube from mouth to anus, intestines coated with mucus, many defenses
The GI tract has various anatomical features that aid in digestion and protection against pathogens.
What are the normal microbiota of the GI tract?
Diverse community of microorganisms residing in the gastrointestinal tract
Normal microbiota play a crucial role in digestion and protection against harmful pathogens.
Define acute diarrhea.
Three or more loose stools in 24 hours
Acute diarrhea can lead to significant health issues, especially in infants.
How common is acute diarrhea in the United States?
1-2 cases per person per year
Approximately 700,000 infants die annually due to complications from acute diarrhea.
What percentage of acute diarrhea cases in the United States is caused by contaminated food?
⅓
Contaminated food is a significant source of acute diarrhea in the U.S.
What is the most severe manifestation of Salmonella enterica?
Typhoid fever
Typhoid fever is characterized by elevated fever and possible septicemia.
What are the symptoms of Salmonella infection?
Vomiting, diarrhea, mucosal irritation
Symptoms typically subside after 2-5 days.
What is Shigella known for?
Human and ape parasites causing frequent and watery stools with blood
Shigella invades the large intestine and releases enterotoxin, damaging the GI tract.
What is dysentery?
Diarrhea with blood
Dysentery is a severe form of diarrhea often associated with Shigella infection.
What is the primary source of E. coli O157:H7 infection?
Undercooked beef
E. coli O157:H7 is linked to various outbreaks, including those from fast-food chains.
What symptoms are associated with Shiga toxin producing E. coli?
Fever, bloody diarrhea, hemolytic uremic syndrome, neurological symptoms
The toxin is identical to that from Shigella and is phage mediated.
What is the most common cause of diarrhea in the United States?
Campylobacter
Campylobacter infections can lead to prolonged symptoms and serious complications.
What is Guillain-Barre syndrome and its relation to Campylobacter?
Leading cause of acute paralysis; 20-40% of cases preceded by Campylobacter infection
Guillain-Barre syndrome is an autoimmune reaction triggered by infection.
What can Clostridium difficile cause?
Causes pseudomembranous colitis
Clostridium difficile can superinfect the large intestine when normal biota is disrupted.
What type of organism is Clostridium difficile?
Gram positive endospore forming rod
It was once thought to be harmless but can cause severe infections.
What do toxins from Clostridium difficile cause?
Necrosis of the cell walls
The toxins produced by Clostridium difficile can lead to severe intestinal damage.
