Brainscape's Knowledge GenomeTM

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


See full index

Micro I > GI Protozoans > Flashcards

GI Protozoans Flashcards

1
Q

How will infection with Giardia lamblia (aka G. intestinalis) present clinically?

A

Intermittent episodes of water diarrhea, NO BLOOD

May be asx or acute/ chronic diarrheal illness

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

G. lamblia is what type of disease?

A

Zoonotic

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

What populations are more greatly affected by G. lamblia?

A

Children, and problematic in IMC (no ability to build antibodies)

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

What is the most commonly identified intestinal parasite in the wold?

A

G. lamblia

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

What are the 2 morphological stages of G. lamblia?

A

Trophozoite and cyst

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

What is the most important structural element of G. lamblia?

A

Flagellate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which morphological stage of G. lamblia is identified by the presence of 4 nuclei and contributes to protection of the organism?

A

Cyst

1 cyst produces 2 trophozoite, each trophozoite has 2 nuclei

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

Which morphological stage of G. lamblia is identified as teardrop shape with a bi-lobed ventral adhesive disc with 2 nuclei?

A

Trophozoite

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

The trophozoite form of G. lamblia feeds on mucus tissues and has what effect on tissues/ RBCs?

A

Does not invade tissue or destroy RBCs

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

How does G. lamblia become infectious?

A

Ingestion of the cyst from contaminated food/ water

highly contagious!

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

How does G. lamblia transition between the trophozoite and cyst stages? (5 steps)

A
  1. Ingest cyst (infectious)
  2. Excystation in stomach = trophozoite
  3. Trophozoite divides in small bowel
  4. Trophozoites in large bowel encyst
  5. Cysts passed into environment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where is infection with G. lamblia most common?

A 
Western states (Rocky Mountains) 
(contributes ~2.5 mill deaths in combo w malnutrition/ co-infection)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

G. lamblia is an infectious disease (including as an STI). How many cysts are considered to be an infectious dose?

A

10-25 cysts, >25 cysts = 100% infection rate

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

How can infection with G. lamblia contribute to malnutrition?

A

Vitamin B12 deficiency

organism feeds on it

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

What are the virulence factors of G. lamblia? (2)

A
  1. Ventral disc implants (“sucker”)

2. Malabsorption of intestinal tissue

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

What is the gold standard for diagnosis of G. lamblia?

A

Microscopic visualization of cysts/ trophozoites in stool samples
(O&P = egg and parasite examination)

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

What may be necessary for diagnosis of G. lamblia due to the shedding of cysts?

A

Multiple stool samples

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

Why can serological tests be problematic for the identification of G. lamblia?

A

Antibodies can be carried for > 2 years

if antibodies present, you will always test positive

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

What is the prognosis of infection with G. lamblia?

A

Most pts asx, self-limited but re-infections possible (if you did not build protective antibodies)

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

How is infection with G. lamblia controlled?

A

Purified water, avoid fecal contamination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What pathogen is responsible for a protozoan illness that can result in colitis and liver abscess?

A

Entamoeba histolytica

many species but only one associated with human disease

22
Q

What is the importance of E. dispar in relation to E. histolytica?

A

Does not cause disease but gets in the way of identifying E. histolytica (commensal)

23
Q

What organism has a non-flagellated trophozoite form with 1 nucleus and an infectious cyst form with 4 nuclei?

A

E. histolytica

24
Q

What does E. histolytica feed off that leads to an important clinical symptom?

A

RBCs (use as nutritional source) = bloody stool

25
Q

How does the life cycle of E. histolytica continue after the ingestion of cysts?

A

Become trophozoites and colonize the colon

Trophozoites do not survive well in environment

26
Q

Once the trophozoite form of E. histolytica colonizes the mucosa of the colon, it may encyst and be passed in feces or invade what?

A

Invade intestinal mucosal barrier and gain access to the blood stream = dissemination

27
Q

What is important about the epidemiology of E. histolytica? (3)

A
  1. Tropical areas
  2. Passed via contaminated water/ food
  3. Reportable disease
28
Q

Disease via E. histolytica can be initiated by a small number of cysts and has diverse manifestations. What clinical presentations are the most common?

A

Acute amoebic colitis/ bloody stools

Dysentery to extraintestinal manifestations

29
Q

Amoeba of E. histolytica hydrolyze the intestinal lining which results in what?

A

Results in ulcers, R upper quadrant pain

large scale ulceration

30
Q

What are the virulence factors of E. histolytica? (4)

A
  1. Lectin (adhesion)
  2. Phospholipases (disrupt host membranes)
  3. Amoebapore (host cell lysis)
  4. Cysteine proteases (“chew away” other proteins)
31
Q

How is infection with E. histolytica diagnosed?

A

Trophozoites/ cysts in stool sample
Radiology for extraintestinal disease
(also ELISA or PCR)

32
Q

How is infection via E. histolytica controlled?

A

Purify water (cysts resistant to chlorine), avoid fecal contamination

33
Q

Although infection with Cryptosporidosis can be caused by multiple species, which species have humans as the only host?

A

Cryptosporidium hominis

C. parvum bovine and human hosts

34
Q

What population is more commonly affected by Cryptosporidium and how are healthy individuals affected?

A

Children, self limiting diarrheal illness in healthy individuals

35
Q

What organism has the following 2 morphological forms: oocytes and sporozoites?

A

Cryptosporidium

36
Q

Which stage of Cryptosporidium is infectious and how does it multiply?

A

Oocytes = infectious, does not multiply outside of the host

37
Q

The life cycle of Cryptosporidium involves binding to the receptors on small intestine epithelial cells followed by what?

A

Ingested into parasitophorous vacuole

38
Q

Once Cryptosporidium organisms are inside the epithelial cells, the parasite undergoes sexual and asexual reproduction to form what?

A

Thin walled oocytes (asexual) = reinfection

Thick walled oocytes (sexual) = shed into environment

39
Q

Identification of what on morphology is important to identify Cryptosporidium?

A

Parasitophorous vacuole

40
Q

What is important about the epidemiology of Cryptosporidium?

A

Contaminated water, recreational water, pools (cysts resistant to chlorine)

41
Q

When are the oocytes of Cryptosporidium infectious?

A

Immediately after excretion

42
Q

What is the cardinal symptom of infection with Cryptosporidium?

A

Watery diarrhea

also pt severely wasted, ~2 weeks, common if IMC

43
Q

How is infection via Cryptosporidium identified?

A

Isolation of oocytes in stool sample (acid-fast oocytes are round)

44
Q

What is the causative agent of infection with Cyclosporiasis?

A

Cyclospora cayetanensis

45
Q

How is Cyclospora cayetanensis transmitted?

A

Contaminated water and imported foods (esp fresh fruits and vegetables from Latin America)

46
Q

When is Cyclospora cayetanensis infectious?

A

Not immediately, oocytes shed in feces and then MUST first sporulate/ survive in the environment

47
Q

What are the oocytes of Cyclospora cayetanensis resistant to?

A

Chlorine

48
Q

What is the most identifiable clinical presentation of infection with Cyclospora cayetanensis?

A

Explosive, non-bloody, watery diarrhea

49
Q

How is infection with Cyclospora cayetanensis identified on microscopy?

A

Large oocyte identified in stool sample, acid fast postiive, autofluorescent oocyte
(much larger than Cryptosporidium)

50
Q

What GI protozoan is characterized by the following:
Disease via ingestion of cysts from contaminated food/ water (from animal feces)
Large central vacuole surrounded by nuclei

A

Blastocystis hominis

51
Q

What GI protozoan is characterized by the following:
Zoonotic (pigs), fecal matter
Can result in gut perforation (but no blood in stool)
Trophozoite and cyst forms contain MACROnucleus
Cilia evident on trophozoite

A

Balantidium coli

Micro I (9 decks)

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