EXAM #1: BACTERIAL INFECTIONS OF THE GI TRACT Flashcards Preview

Gastrointestinal System > EXAM #1: BACTERIAL INFECTIONS OF THE GI TRACT > Flashcards

Flashcards in EXAM #1: BACTERIAL INFECTIONS OF THE GI TRACT Deck (81):
1

What are the symptoms of Botulism poisoning?

1) Dizziness
2) Dry mouth
3) Blurred vision
4) Abd. sx
5) Progressive paralysis

2

What causes Botulism?

Improperly canned (non-acidic food)

3

When do the symptoms of Botulism start?

12-36 hours after ingestion

4

Is fever present in Botulinism?

No--only ingested toxin, NOT whole pathogen

5

What organism causes Botulinism?

C. botulinum

6

List the characteristics of C. botulismsm.

Gram positive
Spore forming
Rod-shaped
Anaerobic

7

What kind of toxin is the C. botulinum toxin?

A-B Bacterial toxin

8

What is the MOA of the C. Botulinum toxin?

1) B portion attaches to receptors on motor nerve endings
2) A portion enters nerve cell
3) Toxin blocks release of ACh

9

What causes Floppy Baby Syndrome?

C. Botulinum spore ingestion

10

What are the symptoms of Floppy Baby Syndrome?

Constipation followed by generalized paralysis

11

Where are C. botulinum spores and toxins identifiable in Floppy Baby Syndrome?

Feces

12

How is Botulsim treated?

Antitoxin administration

13

What is a major adverse effect of Botulism antitoxin administration?

Serum sickness

14

What are the characteristics of Clostridium difficile?

Gram positive
Spore forming
Rod-shaped
Anaerobic

15

What does Clostridium difficile cause?

Antibiotic associated pseudomembranous colitis

16

What is the most common cause of nosocomial diarrhea?

Clostridium difficile

17

How is Clostridium difficile transmitted?

Fecal-oral

18

What antibiotic was the first abx to cause pseudomembranous colitis?

Clindamycin

19

What are the most common causes of pseudomembranous colitis today?

2nd and 3rd generation cephalosporins (only b/c they are the most frequently used)

20

What are pseudomembranes?

white-yellow plaques on the colonic mucosa

21

What is a severe complication of Clostridium difficile infection?

Toxic megacolon

22

How do you tell the difference between adverse diarrhea with abx administration vs. Clostridium difficile?

Clostridium difficile toxin present in the stool

23

How is Clostridium difficile treated?

1) Withdraw antibiotic
2) Oral metronidazole* or vancomycin
3) Fluid replacement

*Preferred

24

What is Shigellosis?

Dysentery i.e. bloody diarrhea

25

List the characteristics of Shigella dysenteriae.

Gram negative
Rods
Non-lactose fermenting

26

How does Shigella dysenteriae appear on MacConkey agar?

Colorless b/c non-lactose fermenting

27

How is Shigella dysenteriae distinguished from Salmonella?

1) Do NOT produce H2S
2) Non-glucose fermenting
3) Non-motile

28

What infective dose is required for Shigella dysenteriae infection? How does this compare to Salmonella?

Shigella dysenteriae= low

Salmonella= high

29

What type of diarrhea is seen with Shigella dysenteriae?

Bloody diarrhea

30

What is the typical symptom progression in Shigella dysenteriae infection?

1) Fever, abdominal cramping and diarrhea
- Watery diarrhea at first
- Bloody/ mucousy diarrhea

31

What strain of Shigella causes a much milder disease than Shigella dysenteriae?

Shigella sonnei

32

What strain of Shigella is most common in the US?

Shigella sonnei

33

What is the drug of choice to treat Shigella dysenteriae?

A fluoroquinolone i.e. Ciprofloxacin

34

What is the drug of choice for Shigella dysenteriae in kids?

TMP-SMX

35

What drugs are contraindicated in Shigella dysenteriae?

Antiperistaltic drugs

36

Why are Fluoroquinolones NOT used in kids?

Increased risk of tendinitis and tendon rupture, especially in kids

37

List the different infections caused by Salmonella species.

1) Enterocolitis
2) Typhoid fever
3) Septicemia
4) Osteomyelitis

38

List the characteristics of Salmonella.

Gram negative rod
Non-lactose ferm.
Produce H2S

39

What antigens are associated with Salmonella?

O= LPS
H= Flagella
K= Capsule

40

What is the species of Salmonella most responsible for entercolitis?

Salmonella typhimurium

41

What is the important host defense against Salmonella typhimurium ?

Gastric acid

42

What does gastrectomy and use of antacids do to the infectious dose of Salmonella typhimurium ?

Lowers it

43

What disease is caused by Salmonella typhi?

Typhoid Fever

44

Where does Salmonella typhi replicate?

Mononuclear phagocytes of the Peyer's Patches

45

After Salmonella typhi enters the GI tract, where does it go?

1) Liver
2) Gallbladder
3) Spleen

****Organism likes the gallbladder and can develop a carrier state there*****

46

What is the typical course of Salmonella in a healthy individual?

Non-bloody diarrhea that does NOT require medical care

47

What patient populations are at risk of life-threatening Salmonella infection?

1) Kids
2) Elderly

48

What are the symptoms of Typhoid Fever?

1) Flu-like symptoms
2) Fever/ constipation
3) Bactermeia
4) Rose-spots

49

How is Salmonella Enterocolitis treated?

Fluid and electrolyte replacement

50

When are antibiotics indicated in Salmonella Enterocolitis?

Only in those at risk for septicemia

51

What drugs should be used to treat Salmonella enteric fever, septicemia, severe enterocolitis?

Ceftriaxone or ciprofolaxcin

52

What surgical procedure may be required to abolish the carrier state of Salmonella?

Cholecystectomy

53

List the characteristics of E. Coli species.

Gram negative rod
Ferments lactose
Facultative anaerobe

54

What is the most common cause of traveler's diarrhea?

E. coli

55

What is ETEC?

Enterotoxigenic E. Coli

56

What specific strain of E. coli is responsible for traveler's diarrhea?

ETEC

57

What is the MOA of the ETEC toxin? What symptom does this toxin cause?

ETEC toxin is similar to the cholera toxin and causes a WATERY DIARRHEA

58

What type of diarrhea is seen in ETEC?

Non-bloody

59

What is EIEC?

Enteroinvasive E. coli

60

What type of diarrhea is seen in EIEC?

Blood and pus in feces

61

What is EPEC?

Enteropathogenic E. coli

62

What does EPEC cause?

Chronic diarrhea in infants

63

What type of diarrhea is seen with EPEC?

Watery diarrhea containing mucous

64

What is EHEC?

Enterohemorrhagic E. coli

65

What toxins are seen in EHEC?

Shiga-Like Toxins 1 and 2 i.e. "SLT-I and SLT-II"

66

What are the symptoms of EHEC infection?

Severe disease with bloody diarrhea

67

What is an adverse effect of EHEC infection?

HUS

68

What is HUS?

Hemolyticuremic Syndrome characterized by:
1) Microangiopathic hemolytic anemia
2) Thrombocytopenia
3) Acute kidney injury

****This is the leading cause of acute renal failure in children worldwide*****

69

What antibiotics should be given to infants with E. coli infection?

Gentamycin
Polymyxin

70

How is traveler's diarrhea treated?

Bismuth preparations

71

What type of diarrhea is "pathogmneomonic" for Cholera?

"Rice-water stool" i.e. severe watery diarrhea

72

Are neutrophils present in the stool of patients with Cholera?

NO

73

What are the characteristics of Vibrio cholerae?

- Curved gram negative rod
- Tolerates strong alkaline conditions
- Tolerates high salt concentrations

74

What is the MOA of the Cholera toxin?

- Heat-labile
- AB subunit protein
- B-binds to receptors on microvilli
- A-activates adenylate cyclase (increases cAMP)

75

How is Cholera treated?

Rapid replacement of fluids and electrolytes

76

What are the characteristics of Campylobacter jejuni?

- Curved gram negative rod
- Microaerophilic

77

How are severe Campylobacter jejuni infections treated?

Erythromycin or ciprofloxacin

78

What disease is caused by H. pylori?

Infectious gastritis

79

What are the characteristics of H. pylori?

Gram negative
Microaerophilic
Short/ spiral shaped
Polar flagella

80

What allows H. pylori to survive in that acidic environment of the stomach?

Urease enzyme that creates an alkaline microenvironment

81

How is H. pylori diagnosed?

Urea breath test