L23(Part1) - B Flashcards by Katlyn Heneghan

____: Association in which one organism derives benefit (parasite) to the detriment of other (host)

____: A parasite that lives within body/internal body passages of its host

____: A parasite that lives on the body surface of the host

Parasitism
Endoparasite
Ectoparasite

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____: Host which harbors adult SEXUAL stage of parasite

____: host which harbors ASEXUAL stage of parasite; essential to parasite lifecycle; transfers parasite from one definitive host to another

Definitive (sexual)
Intermediate (asexual)

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______: A vertebrate host that provides a source of parasitic infection to another host in nature

_______: A carrier (usually arthropod) that transmits causative organism of the disease from an infected to an uninfected indivudla

Reservoir

Vector

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_____: Dormant, immotile stage that permits survival when environmental conditions are hostile

______: Motile, active feeding and reproducing vegetative stage

_____: The encapsulated fertilized ovum of certain sporozoa

Cyst

Trophozoite

Oocyst

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True or False: A Sporozoan is a protozoan with complex life stages (includes: sexual and asexual stages)

True

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True or False: Treatment of protozoan parasites are not easy since they are multicellular, prokaryotic organisms

False - Treatment of protozoan parasites are not easy since they are UNICELLULAR and EUKARYOTIC organisms

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How do protozoan parasite reproduce?

Mitotic division (bin fis)
Meiosis

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True or False: Trichomonas vaginalis is the only protozoa that causes uro-genital infections

True

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What are the four major protozoal groups, classified according to mode of locomotion?

1) Amebas
2) Flagellates
3) Ciliates
4) Sporozoa

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Which of the following protozoa is an Ameba?
A. Giardia
B. Trichomonases
C. Toxoplasma
D. Enamoeba histolytica

D. Enamoeba histolytica

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Which two protozoa are flagellates?
A. Giardia
B. Trichomonases
C. Toxoplasma
D. Enamoeba histolytica

A. Giardia
B. Trichomonases

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Which two protozoa are flagellates?
A. Giardia
B. Trichomonases
C. Toxoplasma
D. Enamoeba histolytica

A. Giardia
B. Trichomonases

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True or False: Naegleria fowleri is neither an ameba nor a flagellates. Rather, it is something in between.

True

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Which four protozoa are sporozoa (PCB + T)?

Plasmodium
Cryptosporidium
Babesia
Toxoplasma

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In the trophozoite form, ______ is an active and vegetative amoeba found in the colon that EATS RBC’s and releases PROTEASES (virulence factor!!!)
A. E. histolytica
B. G. lamblia
C. Cryptosporidium parvum

A. E. histolytica

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Which stage of E. histolytica is mostly found in formed stool and allows for transmission and infection of NEW host?
A. Cyst
B. Trophozoite
C. Oocyst

A. Cyst

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True or False: In the trophozoite form of E. histolytica, the nucleus has a “ring and dot” appearance (peripheral chromatin + karysome)

True

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The E. histolytica life cycle:

Ingested form is ___
Excysts in which organ?

A. cyst; small intestine
B. oocyst; large intestine
C. trophozoite; colon

A. cyst; small intestine

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In the E. histolytica life cycle, trophs live in the ____ via releasing which enzyme?

Lives in colon
Releases: proteases

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How can E. histolytic disseminate to multiple organs?

Via use of protease

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When does the cyst for of E. histolytica form?

Feces forms and dries in colon

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True or False: E. histolytica is transmitted via food and water and dysentary (bloody diarrhea) is the main manifestation

True

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Flask shaped amoebic ulceration, or liver/brain abscess suggests infection by which pathogen?

E. histolytica

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True or False: E. histolytica primarily targets the liver and exists in asymptomatic carrier state

True

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Which three conditions are associated with infection with E. histolytica?

1) Amoebic dysentery/colitis - blood + mucus in stool 2) Amoebic liver/brain abscesses 3) Amoeboma

How do you dx E. histolytica?

Microscopic examination of feces (x3 stool) -Diarrheric feces - trophozoites -Formed stool - cysts

Which pathogen is found (in trophozoite) in the duodenum and upper jejunium, has "falling leaf" motility, as well as a characteristic "spook" appearance. A. E. histolytica B. G. lamblia C. Cryptosporidium parvum

B. G. lamblia

What triggers the cyst for of G. lamblia? Where is it found? A. low Na/large intestine B. high Na/small bowel C. dehydration/large bowel D. dehydration/small bowel

C. dehydration/large bowel

For G. lamblia, how does one ingest the cyst?

Fecally contaminated food or drink

Where does G. lamblia excysts? How does it attach to microvilla? A. Large intestine; sucking disks B. Small intestine; suckers C. Large intestine; suckers D. Small intestines; sucking disks

D. Small intestines; sucking disks

True or False: G. lamblia invades villi of the small intestine

False - G. lamblia trophozoites live on surface of villi, but do NOT invade (non-invasive)

How are G. lamblia cysts formed? Where are cysts commonly found?

Formed: as trophs dehydrate Found: formed stool

Villous atrophy and blunting (lawnmower effect) suggest infection by which microbe?

G. lamblia

Which pathogen is a common cause of waterborne diarrhea outbreaks and can be transmitted via: food or fecal contamination of food/water?

G. lamblia

___ are the main reservoir of G. lamblia (but mammals and avians may also harbor..)

Humans

True or False: Individuals infected with G. lamblia and symptomatic have interference w/fat and protein absorption. By contrast, carriers are histologically normal, but shed cysts in their stool.

True

Statorrhea (excess fat in stool) suggests infection by which microbe?

G. lamblia

Which stain can you do to detect presence of excess fat in stool?

Direct Fecal Sudan Stain

True or False: PCR/ELISA can be used to diagnose G. lamblia

False - can dx E. histolytica

How do you dx G. lamblia?

- Stool exam x 3 days - Endoscopy - Enterotest (duodenal string)

In G. lamblia, ____ are found in formed stools while ____ are found in loose/diarrheic stools A. trophozoites; cysts B. cysts; trophozoites

B. cysts; trophozoites

_____ is a sporozoan related to pathogens causing malaria and toxoplasmosis A. E. histolytica B. G. lamblia C. Cryptosporidium parvum

C. Cryptosporidium parvum

How can you see morphology of C. parvym?

Stain w/ Giemsa or H&E (acid fast)

_____: A microbe the requires intracellular residences (obligate intracellular parasite) + deep tissue invasion occurs only in immunocompromised hosts

Cryptosporidium parvum

True or False: Stool smear can be used to identify oocyst of C. parvum

True

True or False: The thin walled oocyst (sporulated) form of C. parvum exits host, contaminates food/water, then is ingested by host

False - thick walled !!!

Describe the life cycle of C. parvum

In the lifecycle of C. parvum, _____ are release from oocyte and attach to microvilli, becoming ____ (obligate intracellular protozoans) A. cysts; meronts B. trophozoites; meronts C. sporozoites; meronts

C. sporozoites; meronts

What is asexual vs. sexual reproduction known as in the C. parvum life cycle?

Asexual: Merogony Sexual: Sporogony

True or False: In C. parvum, oocysts are the result of asexual reproduction

False - SEXUAL reproduction

True or False: In C. parvum, thin walled oocyts are shed in stool while thick-walled oocyts auto-infect

False Thin walled = autoinfect Thick walled = shed in stool

In C. parvum, Type 1 meront is involved in ____ cycle while Type 2 meront is involved in ____ cycle A. sexual; asexual B. asexual; sexual C. asexual; asexual D. sexual; sexualt

B. asexual; sexual

Infection by ____ occurs primarily via: fecal-oral spread. However, it has emerged as the most frequently recognized cause of recreational watter-associated outbreaks of gastroenteritis.

C. parvum

True or False: Oocysts of C. parvum are more resistant to chlorine and removal by water sanitation than G. lamblia

True

C. parvum usually infects jejunum, but found throughout GI tract in which patients?

Immunocompromised

How do symptoms of C. parvum compare in immunocompetent vs. immunocompromised patients?

How can you identify oocysts in C. parvum?

-AF staining / Direct immunofluorescence - Anti-crytosporidia Ab

Prophylaxis for C. parvum?

True or False : Trichomonas vaginalis, which causes urogenital infections, is a flagellate

True

How are Acanthamoeba and N. fowleri similar? different?

Both environmental amoebas - N. fowleri is also a flagellate

True or False: Plasmodium, Babesia, and Toxoplasma are sporozoan

True

____ is the only protozoan known to be transmitted via sex

T. vaginalis

In Trichcomonas, when trophozite is in vaginal/prostatic secretions and urine, it is in ____ stage A. Infective B. Diagnostic

B. Diagnostic

True or False: Trichomonas vaginalis prefers a more acidic environment

False - basic

True or False: In males, trichomonas often lives on urethral surface, prostate, seminal vesicles -- but is often asymptomatic By contrast, in females, it can cause discharge, vaginitis, and desquamation (does not invade beyond epithelium!)

True

Strawberry cervix suggests infection by ____

Trichomonas

How do you dx Trich?

1) Motile trichomonads via wet mount 2) Elevated pH in vaginal fluids 3) Frothy discharge