L23(Part1) - B Flashcards
____: 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
____: 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)
______: 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
_____: 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
True or False: A Sporozoan is a protozoan with complex life stages (includes: sexual and asexual stages)
True
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
How do protozoan parasite reproduce?
Mitotic division (bin fis)
Meiosis
True or False: Trichomonas vaginalis is the only protozoa that causes uro-genital infections
True
What are the four major protozoal groups, classified according to mode of locomotion?
1) Amebas
2) Flagellates
3) Ciliates
4) Sporozoa
Which of the following protozoa is an Ameba?
A. Giardia
B. Trichomonases
C. Toxoplasma
D. Enamoeba histolytica
D. Enamoeba histolytica
Which two protozoa are flagellates?
A. Giardia
B. Trichomonases
C. Toxoplasma
D. Enamoeba histolytica
A. Giardia
B. Trichomonases
Which two protozoa are flagellates?
A. Giardia
B. Trichomonases
C. Toxoplasma
D. Enamoeba histolytica
A. Giardia
B. Trichomonases
True or False: Naegleria fowleri is neither an ameba nor a flagellates. Rather, it is something in between.
True
Which four protozoa are sporozoa (PCB + T)?
Plasmodium
Cryptosporidium
Babesia
Toxoplasma
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
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
True or False: In the trophozoite form of E. histolytica, the nucleus has a “ring and dot” appearance (peripheral chromatin + karysome)
True
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
In the E. histolytica life cycle, trophs live in the ____ via releasing which enzyme?
Lives in colon
Releases: proteases
How can E. histolytic disseminate to multiple organs?
Via use of protease
When does the cyst for of E. histolytica form?
Feces forms and dries in colon
True or False: E. histolytica is transmitted via food and water and dysentary (bloody diarrhea) is the main manifestation
True
Flask shaped amoebic ulceration, or liver/brain abscess suggests infection by which pathogen?
E. histolytica
True or False: E. histolytica primarily targets the liver and exists in asymptomatic carrier state
True
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
