Intestine Flashcards
What are 5 morphologic classifications of inflammatory intestinal disease?
What are 5 morphologic classifications of inflammatory intestinal disease?
- Hemorrhagic enteritis (Clostridium)
- Fibrinous, Necrotic & Fibrinonecrotic enterocolitis (Salmonella)
- Ulcerative enterocolitis (ischemia, BVD)
- Suppurative or pyogranulomatous enterocolitis (Rhodococcus)
- Proliferative or hyperplastic enteritis (Coccidiosis)
- Granulomatous enterocolitis (Johne’s)
When is hemorrhagic enteritis mostly commonly seen? (3)
When is hemorrhagic enteritis mostly commonly seen? (3)
- Acute chemical intoxications (such as arsenic posoning)
- Bacterial diseases (Clostridial & Campylobacter infections)
- Actue coccidiosis
Example of fibrinous, necrotic, and fibrinonecrotic enterocolitis
Example of fibrinous, necrotic, and fibrinonecrotic enterocolitis
Salmonella, Swine dysentery, BVD
**Example of Ulcerative enterocolitis **
**Example of Ulcerative enterocolitis **
Hog Cholera
Ischemia
BVD
**Example of suppurative or pyogranulomatous enterocolitis **
**Example of suppurative or pyogranulomatous enterocolitis **
Strep. equi
Corynebacterium equi (Rhodococcus or Actinomyces)
**Example of proliferative or hyperplastic enteritis **
**Example of proliferative or hyperplastic enteritis **
Coccidiosis
Lawsonia intracellularis (pigs)
Campylobacter (hamsters)
Example of Granulomatous enterocolitis
Example of Granulomatous enterocolitis
Johne’s disease
Equine granulomatous enteritis
What form of Escherichia coli infection can cause abnormal intestinal function without producing any morphologic changes in the intestinal mucosa?
What form of Escherichia coli infection can cause abnormal intestinal function without producing any morphologic changes in the intestinal mucosa?
Septicemic colibacillosis
(Intestinal lesions and diarrhea are NOT always present because organisms can penetrate into circulatory system via the umbilicus, intestinal and respiratory tracts)
**Describe septicemic colibacillosis gross lesions **
**Describe septicemic colibacillosis gross lesions **
- Minimal, if death mediated largely by effects of bacterial endotoxin
- When sufficient time for antemortem localization and an inflammatory reaction to occur -
- Acute fibrinous or fibrinopurulent polyarthritis
- Panophthalmitis
- Peritonitis
- Meningitis
- Acute pneumonia
Describe septicemic colibacillosis mechanism of action
Describe septicemic colibacillosis mechanism of action
Describe septicemic colibacillosis histopathology
Describe septicemic colibacillosis histopathology
Describe enterotoxigenic colibacillosis gross lesions
Describe enterotoxigenic colibacillosis gross lesions
Similar to viral enteritis? except villous lesions not usually seen histologically (except in pigs)
**Describe enterotoxigenic colibacillosis mechanism of action **
**Describe enterotoxigenic colibacillosis mechanism of action **
Bacteria adhere to enterocyte surfaces via pili and production of heat-labile (LT) and heat-stable (HT) enterotoxins. Enterotoxins increase chloride and bicarbonate movement into lumen with concurrent water movement -> Secretory diarrhea
Describe enterotoxigenic colibacillosis histopathology
Describe enterotoxigenic colibacillosis histopathology
Describe enteropathogenic colibacillosis gross lesions
Describe enteropathogenic colibacillosis gross lesions
Effaced microvilli
Villous atrophy & fusion
**Describe enteropathogenic colibacillosis mechanism of action **
**Describe enteropathogenic colibacillosis mechanism of action **
Slide
E. coli binds to surface of enterocytes on microvilli > bacterium injects the translocation intimin receptor into host cell > Host cell signalling pathways subverted > Major host cell cytoskeletal changes result in pedestal formation where bacterium attaches
Notes
Bacteria attach via pili and produce Shiga-like cytotoxin to efface microvilli
**Describe enteropathogenic colibacillosis histopathology **
**Describe enteropathogenic colibacillosis histopathology **
Effaced microvilli
Villous atrophy and fustion in ileum and jejunum
(also damage colonic and cecal epithelium)
Colibacillosis Summary
1) Septicemic
2) Diarrheal
a. Enterotoxigenic
b. Enteroinvasive
c. Enteropathogenic
3) Enterotoxemic
(not a study question)
Colibacillosis Summary
1) Septicemic - Endotoxin
2) Diarrheal
a. Enterotoxigenic - Suface adhesion w/ enterotoxin production
b. Enteroinvasive - Invade epithelial cells (Shiga toxin), necrosis
c. Enteropathogenic - Attaching & Effacing microvilli
3) Enterotoxemic - Exotoxin
How does Salmonella cause enteric disease (pathogenesis)?
How does Salmonella cause enteric disease (pathogenesis)?
Salmonella, in membrane-bound vacoules, enters intestinal epithelial cells and are deposited into lamina propria
Proliferate in macrophages and enter blood
Bacteria killed in phagocytes release endotoxins, enterotoxins or cytotoxins
Induce necrosis, erythema and edema
What portions of the villi are affected by:
Rotavirus
Coronavirus
Parvovirus
What portions of the villi are affected by:
- *Rotavirus -** Tip of villi
- *Coronavirus -** Upper & Middle
- *Parvovirus -** Crypt
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
Parvovirus
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
Parvovirus
Portion of the villus - Crypts (so villi shorten)
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
** Coronavirus**
Describe histologic lesions in the small intestine & what portion of the villus are affected by:
Coronavirus