Infections of the Small Intestine Flashcards
Bugs the small intestine is typically colonized by?
It typically is not colonized
Bugs that infect the small intestine?
Toxigenic E. coli and Vibrio cholerae
What factors limit bacterial growth?
- Gastric acid inhibits bacterial growth
- Bile has antimicrobe action
- Peristalsis propels bacteria out
- Plasma cells of lamina propria secrete IgA into the intestinal lumen
Prototypical organisms that cause diarrhea by secreting toxins are?
Vibrio cholerae and toxigenic strains of E. coli
Characteristics of toxigenic bacteria?
- Damage to intestinal mucosa is minimal or absent
- Organism remains on the mucosal surface
- Watery diarrhea
What is the pathogenesis of invasive bacteria?
Invade and directly injure the intestinal mucosa
Typical invasive bacteria?
- Shigella salmonella
- E. coli (some strains)
- Yersinia
- Campylobacter
Typical site of infection of invasive bacteria? Toxigenic?
- Invasive - Distal ileum and colon
- Toxigenic - Upper intestinal tract
Worst complications of typhoid fever?
Intestinal hemorrhage and perforation
What condition are those with salmonella susceptible to getting?
Salmonella osteomyelitis
What condition has 0157:H7 E. coli been implicated in children?
Hemolytic uremic syndrome
What does Yersinia enterocolitis mimic?
Appendicitis due to right lower quadrant pain
What condition predisposes people to Yersinia enterocolitica infection?
Thalassemia
From what source do humans contract campylobacter jejuni?
Contact w/ infected domestic animals or by eating poorly cooked/contaminate food
What two agents typically cause food poisoning via exotoxin?
- Staphylococcus aureus
- Clostridium perfringens
