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Flashcards in Micro 7 - Diarrhea Deck (52)
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What are the four types of Escherichia coli?

1. Enterotoxigenic E. coli (ETEC) 2. Enterohemorrhagic E. coli (EHEC) 3. Enteropathogenic E. coli (EPEC) 4. Enteroinvasive E. coli (EIEC)


Describe Enterotoxigenic E. coli (ETEC).

1. Water diarrhea due to heat-liable and heat stable enterotoxins. 2. Does not infect the intestinal wall 3. Most common type of traveler's diarrhea.


Describe enterohemorrhagic E. coli (EHEC).

1. Bloody diarrhea and severe illness from infected meat. 2. Most common is 0157:H7 3. Produces shiga-like toxins. 4. Can lead to hemolytic uremic syndrome (HUS): anemia, thrombocytopenia, acute renal failure. Treatment: supportive.


Describe Enteropathogenic E. coli (EPEC).

1. Watery diarrhea, but not toxin produced. 2. Common in children.


Describe Enteroinvasive E. coli.

1. Bloody diarrhea and fever due to intestinal wall invasion. 2. Closely related to Shigella.


What is the treatment for Enteroinvasive E. coli (EIEC)?

Fluoroquinolones, TMP-SMX, azithromycin.


Describe clinical features of Shigella.

1. Causes watery diarrhea that turns to bloody diarrhea by invading the intestinal mucosa, causing inflammation and necrosis. Causes mucus and fever. 2. Produces Shiga toxins as well. 3. Lasts for 1-2 weeks. 4. It is a non-lactose fermenter.


How is Shigella spread?

1. Person to person contact. 2. Contaminated food and water.


How does Shigella differ from Salmonella in terms of their anatomical structure?

Shigella does not have flagella. Salmonella does.


What is the treatment for Shigella?

Suppurative. In severe cases: Fluoroquinolones = 1st line. TMP-SMX or azithromycin = 2nd line or pediatrics.


Which bacteria infections are related to cause Reiter syndrome?

1. Shigella flexneri 2. Salmonella


What is the clinical presentation of Salmonella?

1. Bloody diarrhea and fever that begins 1-3 days later. 2. Non-lactose fermenter 3. Picnic setting, egg salad or chicken salad. 4. Turtles, pet stores.


How is salmonella diagnosed?

Stool culture.


What is the treatment for salmonella?

Healthy adults need only supportive care. In intense cases, fluoroquinolones = 1st line.


What is the bacteria that needs to be suspected in osteomyelitis in sickle cell patients?

Salmonella due to having flagella that gives them ability to spread hematogenously.


What is classic clinical presentation of Salmonella typhi?

"Rose spots" on the abdomen.


Describe campylobacter jejuni.

1. G(-) 2. Z-shaped 3. Oxidase positive 4. Bloody diarrhea, especially in children 5. Grows in at 42C [Campylobacter likes it hot like a camp fire] 6. Self-limited but can last for 1-2 weeks.


How is Campylobacter jejuni transmitted?

Fecal-oral; poultry, meat, unpasteurized milk.


Which disease is campylobacter jejuni associated with?

Guillain-Barre syndrome.


Describe Vibrio cholerae.

1. G(-) 2. Oxidase positive bacilli 3. Watery diarrhea "Rice-water"- Causes profound diarrhea. 4. Flagellum 5. Grows in alkaline media


What does the toxin of Vibrio cholerae do?

Permanently activates cAMP.


What is the treatment for Vibrio cholerae?

Aggressive oral rehydration.


What disease can Yersinia enterocolitica cause that can mimic appendicitis?

Mesenteric adenitis


How is Yersinia enterocolitica spread?

From undercooked pork and milk and hosehold pets.


Describe Klebsiella pneumoniae.

1. G(-) 2. Lactose fermenting 3. Normal intestinal flora 4. Affects people with weakened immune systems: alcoholics, dibatics, chronic illness.


What pathologies does Klebsiella pneumoniae cause?

1. Lobar pneumonia 2. Red currant jelly sputum 3. Necrosis in the lungs 4. Major cause of UTIs


Describe Clostridium difficile.

1. Gram (+) 2. Oxidase negative 3. Spore-forming bacilli 4. Produces Toxin A and Toxin B.


What does Toxin A of C. difficile cause?

AKA enterotoxin, binds to the brush border of the gut, leads to intestinal fluid secretion and inflammation.


What does Toxin B of C. difficile cause?

Kills enterocytes by targeting the cytoskeletal structures of the enterocytes. Causes pseudomembranous colitis.


Describe pseudomembranous colitis and primary risk factor.

Necrosis with exudates, fibrin and leukocytes of the colon caused by overgrowth of C. difficile. Primary risk factor is antibiotic use, especially cindamycin and ampicillin.