Bacterial Infections of the GI Tract Flashcards Preview

Medical Microbiology > Bacterial Infections of the GI Tract > Flashcards

Flashcards in Bacterial Infections of the GI Tract Deck (26):
1

Non-inflammatory diarrhea vs inflammatory diarrhea

Non-inflammatory (e.coli) - ingestion of toxin causes elevations in cAMP and watery diarrhea.

Inflammatory (Shigella) - organism colonizes the intestine, cytotoxins cause inflammation, which causes diarrhea.

2

What type of disease is cholera?

Toxin-mediated. Caused by vibrio cholerae.

3

Vibrio cholerae characteristics

Curved/straight bacilli. Gram negative, 150o serotypes, but only 1 and 139 are cholerogenic.

4

Where does vibrio cholerae live?

Aquatic environments

5

Clinical symptoms of cholera

Devastating watery diarrhea, vomiting

6

Main defense against cholera?

Gastric acidity

7

How is cholera toxin created?

Lysogenic phage integrates into genome, activated when vibrio is in right temperature and sugar concentration.

8

TCP pilus

On vibrio cholerae, important for attachment and colonization of vili.

9

What type of toxin is choleratoxin?

AB toxin. 2 types of A's. Increases cAMP in body.

10

Therapy for choleratoxin?

Rehydration

11

Shigella appearance

Non-lactose fermenting gram negative rods

12

What does shigella cause?

Dysentery

13

What are the symptoms of dysentery?

Small volume, bloody diarrhea. Abdominal cramps/pain, tenesmus (straining).

14

What is the shigella reservoir?

Humans, transmitted from person to person, common in children.

15

What part of shigella dysenteriae causes dysentery?

Shigatoxin shuts down cell and causes death.

16

Salmonella species characteristics

Gram negative rods, facultatively anaerobic, motile, no fermentation of lactose/sucrose

17

Which salmonella causes enteritis?

S. typhimurium

18

Which salmonella causes typhoid fever?

S. typhi

19

Salmonella gastroenteritis symptoms

N/V within 48 hours, urgency, diarrhea can vary.

20

Typhoid fever.

Systemic disease with multiorgan disfunction. Prolonged fever, sustained bloodstream infection. Passes from stool to blood

21

How can you get a non-thyphoidal salmonella infection?

Agricultural products like eggs, processed food like dairy, domestic animals like iguanas.

22

How is salmonella pathogenic

Survives within macrophages and other non-phagocytic cells, encapsulated

23

How can you get a campylobacter infection?

Handling chicken. Little person to person transmission.

24

What is the worst case scenario w/campylobacter?

Guillain Barre syndrome. Most of the time the disease is self-limiting.

25

Heliobacter Pylori

Causes gastric ulcers, not diarrhea. CLASS 1 CARCINOGEN (gastric adenocarcinoma and MALT lymphoma).

26

Antibiotic treatment for vibrio, campylobacter, salmonella, shigella

Fluoroquinolones, 3rd generation cephalosporins, macrolides. Frequently resistant to amoxicillin, TMPSMZ and 1st generations cephs.