Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medical Microbiology > Lecture 17 > Flashcards

Lecture 17 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards USMLE® Step 1 flashcards
1
Q

What is the GI tract?

A

alimentary canal
- mouth
- pharynx (throat)
- esophagus
- stomach
- small and large intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the accessory structures to the digestive system?

A
  • teeth and tongue
  • salivary glands
  • liver
  • gallbladder
  • pancreas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How much of the immune system is in the intestinal tract? What is the tissue called?

A

70%
- Gut-associated lymphoid tissue (GALT)
- lymph nodes
- Peyer’s patches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are some examples of normal microbiota in the digestive system?

A
  • millions of bacteria in saliva
  • few microorganisms in the stomach (high acidity)
  • paneth cells in small intestines (granule-filled phagocytic cells that produce defensins)
  • aerobes and facultative anaerobes in large intestine
  • 100 billion bacteria in feces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is staphylococcal food poisoning caused by?

A

enterotoxin produced by Staphylococcus aureus
- serological type A: coagulates blood plasma
- can’t be killed by boiling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When are enterotoxins produced? What environment does it thrive in?

A
  • organism is allowed to incubate in food
  • high osmotic pressure and high temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How can we detect enterotoxins?

A

phage typing traces sources of contamination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is another name for Shigellosis? What is it caused by?

A

bacillary dysentery
- Shigella
= facultatively anaerobic gram-negative
= 4 species
= produced by shiga toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can shigellosis be spread?

A

small infectious dose
- attaches to M cells, invades via micropinocytosis and spreads to other cells
- damages intestinal wall
- can invade bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is shigellosis diagnosed?

A

antibiotic sensitivity testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is shigellosis treated?

A

fluoroquinolones + oral rehydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is Salmonella Gastroenteritis caused by?

A

salmonella enterica
- gram-negative
- facultative anaerobe
- nonendospore-forming rods
- normal in the intestinal tract

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does salmonella gastroenteritis work?

A

invades intestinal mucosa and multiplies
- passes through M cells and enters the lymphatics
- replicates in macrophages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the incubation period of salmonella gastroenteritis? What are the symptoms?

A

12-36 hours
- fever
- nausea
- pain
- cramps
- diarrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is salmonella gastroenteritis associated with? How many cases annually?

A

commercial chicken and egg production (bacteria survive in the albumin)
- 1 million cases & 380 deaths annually

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How is salmonella gastroenteritis diagnosed?

A

from the stool or by PCR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is salmonella gastroenteritis treated?

A

oral hydration therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is typhoid fever caused by? How is it spread?

A

Salmonella serotype Typhi
- spread through feces only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does typhoid fever spread through the body?

A

in phagocytes
- releases organisms into the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are symptoms of typhoid fever?

A
  • high fever
  • headache
  • intestinal wall ulceration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How can typhoid fever be treated?

A
  • ceftriaxone
  • azithromycin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is cholera caused by? What is its characteristics?

A

Vibrio cholerae
- slightly curved gram-negative rod with single polar flagellum

23
Q

What does Vibrio cholera produce? What is its purpose?

A

makes cholera toxin
- causes host cell to secrete electrolytes and water
- causes rice water stools

24
Q

What is the treatment of cholera?

A

IV fluid replacement

25
Q

How does incidence of cholera change after natural disasters?

A

cholera increases when sanitation and sewage disposal systems are compromised

26
Q

How can you prepare for natural disasters?

A
  • prepare oral rehydration solutions
  • stockpile vaccines
  • proper sanitation
  • water storage
  • handwashing
27
Q

What are the 5 types of E. coli?

A
  • enteropathogenic E. coli (EPEC)
  • Enteroinvasive E. coli (EIEC)
  • enteroaggregative E. coli (EAEC)
  • enterohemorrhagic E. coli (EHEC)
  • enterotoxigenic E. coli (ETEC)
28
Q

What are the characteristics of EPEC?

A

diarrhea in developing countries
- causes host cells to form pedestals where the bacteria attaches

29
Q

What are the characteristics of EIEC?

A

causes shigella-like dysentery

30
Q

What are the characteristics of EAEC?

A

only in humans
- produces enterotoxin causing watery diarrhea

31
Q

What are the characteristics of EHEC?

A
  • produces shiga-like toxin
  • cattle = main reservoir
  • causes hemorrhagic colitis and hemolytic uremic syndrome
32
Q

How is EHEC diagnosed?

A

inability to ferment sorbitol
- ELISA test

33
Q

What is the cause of traveler’s diarrhea?

A

ETEC
- salmonella
- shigella
- campylobacter

34
Q

How is traveler’s diarrhea treated?

A
  • oral rehydration therapy
  • bismuth-containing preparations
  • antidiarrheal medications
35
Q

What is the characteristic of Clostridium difficile-associated diarrhea?

A
  • gram-positive, endospore-forming anaerobe
  • causes more deaths than all other intestinal infections combined
36
Q

What happens in life-threatening colitis?

A

ulceration and perforation of the intestinal wall

37
Q

What causes Giardiasis? What is the characteristic of it?

A

giardia intestinalis
- flagellated protozoan
- forms cysts in feces and water; trophozoites in the body
- attaches to the intestinal wall

38
Q

What are the symptoms of giardiasis?

A
  • prolonged diarrhea
  • malaise
  • weight loss
  • flatulence
  • cramps
  • hydrogen sulfide in the breath or stools
39
Q

How can giardiasis be diagnosed?

A
  • microscopic examination of stool samples
  • serological fecal tests
40
Q

How can giardiasis be treated?

A

metronidazole and nitazoxanide

41
Q

What is Amebiasis caused by? What does the bacteria cause?

A

entamoeba histolytica
- produces cysts that survive stomach acid
- trophozoites produced form cysts in the intestines
- multiply in the wall of the large intestine

42
Q

What are symptoms of amebiasis?

A
  • blood and mucus in feces
  • can perforate intestinal wall, causing abscesses
  • organisms invade liver
43
Q

How can amebiasis be detected and treated?

A

serological EIA tests
- treat with metronidazole

44
Q

What is beef tapeworm caused by?

A

taenia saginata

45
Q

What is pork tapeworm caused by?

A

taenia solium

46
Q

What is fish tapeworm caused by?

A

diphyllobthrium latum

47
Q

What is taeniasis?

A

adult tapeworm infects intestines

48
Q

What is cysticercosis?

A

infection with larval stage by ingesting eggs

49
Q

What is ophthalmic cysticercosis?

A

larvae lodge in the eye

50
Q

What is neurocysticercosis?

A

larvae develop in the CNS

51
Q

What is the 3-stage life cycle of the tapeworm?

A

1) eggs excreted in feces and ingested by animals
2) eggs hatch into larval cysticercus that lodges in muscle
3) human ingests undercooked meet with cysticerci and develops into adult tapeworms in the intestine

52
Q

How can tapeworms be diagnosed?

A

eggs or segments in the feces

53
Q

How can tapeworms be treated?

A

praziquantel and niclosamide

Medical Microbiology (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions