protozoan Flashcards
1
Q
Protozoans are under Phylum __
A
Sarcomastigophora
2
Q
Protozoans are classified as __, __, __, __
A
intestinal / lumen-dwelling amoeba, free-living amoeba, atrial flagellates, hemoflagellates
3
Q
Amoebae are under Sub-phylum __
A
sarcodina
4
Q
Flagellates are under Sub-phylum __
A
mastigophora
5
Q
Amoebae are characterized by presence of foot-like projections called __
A
pseudopodia
6
Q
Flagellates are characterized by presence of __
A
whip-like flagella
7
Q
pseudopodia of amoebae serves as __
A
locomotory structure
8
Q
important amoebae(s) in humans
A
entamoeba, naegleria, acanthamoeba
9
Q
commensals of amoeba
A
e. coli, e. dispar, e. gingivalis, e. hartmanni, e. moshkovskii
10
Q
pathogenic amoeba
A
e. histolytica
11
Q
species of genus entamoeba capable of infecting man
A
e. histolytica, e. coli, e. dispar, e. gingivalis, e. hartmani, e. moshkovskii
12
Q
zoonotic protozoan of pigs and monkeys
A
e. polecki
13
Q
t/f
e. polecki infections are symptomatic and seldom may cause diarrhea
A
f (asymptomatic)
14
Q
free-living protozoans found mainly in freshwater
A
naegleria, acanthamoeba
15
Q
entamoeba(s) that are hard to differentiate with each other
A
e. histolytica, e. dispar, e. moshkovski, e. hartmanni
16
Q
small race of e. histolytica
A
e. hartmanni
17
Q
all entamoeba are lumen-dwelling (intestinal) except __
A
e. gingivalis (mouth)
18
Q
all entamoeba are non-pathogenic except __
A
e. histolytica
19
Q
infective stage of most entamoeba
A
cyst (except e. gingivalis)
20
Q
first to describe e. histolytica
A
losch
21
Q
species-complex amoeba considered to cause amoebic dysentery and liver abscess
A
e. histolytica
22
Q
parasite of PAM (brain, meninges)
A
naegleria fowleri
23
Q
parasite of GAM (lungs, skin, brain)
A
Acanthamoeba spp and Balamuthia mandrillaris
24
Q
parasite of acantamoeba keratitis (eyes, cornea)
A
acantamoeba spp
25
parasite of amoebiasis (liver, lungs)
e. histolytica
26
parasite of giardiasis (bile duct, gallbladder)
giardia duodenalis
27
parasite of trichomoniasis (prostate, seminal vesicles)
trichomonas vaginalis
28
[e histolytica]
diameter
troph:
cyst:
12-60; 10-20
28
[e histolytica: t]
motility
active, rapid, progressive, unidirectional;
28
[e histolytica]
karyosome
troph:
cyst:
small, central; small, eccentric
29
[e histolytica]
permanent stain
troph:
cyst:
trichrome stain & iron hematoxylin; iron hematoxylin
29
[e histolytica: t]
characteristics with iron hematoxylin stain
cytoplasm: grayish
nuclear structures: bluish black
erythrocytes: similar stain
RBC: progressively paler
30
[e histolytica: t]
characteristics with trichrome stain
cytoplasm: green (occasionally light pink)
nuclear structures: dark red
erythrocytes: cherry red or green
31
presence of ingested RBC in e. histolytica trophozoites is called __
hematophagous trophozoite
32
[e histolytica]
pre-cyst characteristics
single rounded nucleus, absence of ingested material, lack of cyst wall
33
dead or degenerated parasite has a ___ appearance
swiss cheese
34
t/f
structures of amoeba change when kept too long at room temperature
true
34
t/f
phagocytic stomata are not present in e. histolytica
false (presence of 2 stomatas: small endocytic - phagocytosis & larger stomata - pinocytosis)
35
immature cysts are found in what stage
pre-cystic
36
characteristics of an immature cyst
yellow stained glycogen mass (reddish brown w/ iodine stain)
highly refractile chromatoidal bars (rounded edges)
37
chromatoidal shape of e. histolytica
rod-like / cigar-shaped
37
[e. histolytica]
most common form of infection
intestinal amoebiasis (asymptomatic)
38
cycle of e. histolytica
ingestion
excystation (cyst to trophozoite; small intestine)
binary fission (large intestine)
encystation (trophozoite to cyst; intestinal tract)
"round up" (resistant cyst stage)
39
susceptibility of humans to e. histolytica is associated with __
specific alleles of HLA complex
39
[e histolytica]
determining factors of the degree of invasion
number of ingested cysts
pathogenic capacity of strain
host immunity
presence of enteric bacteria
39
patient supplemented with __ and those __ patients may provoke amoebic colitis
corticosteroid; severely burned
39
[e. histolytica]
symptomatic intestinal amoebiasis with presentation of blood and mucus in stools
amoebic dysentery
40
[e. histolytica]
symptomatic intestinal infection / inflammation
amoebic colitis
41
mortality cases are high among __ women in relation with the amoebic severity and __ stress
pregnant; maternal
42
degrades of host proteins; enables attachment to the gut; degrades mucus and debris; stimulates host cell proteolytic cascades
cysteine proteinases
42
responsible for cellular adherence, contact-dependent toxicity, resistance to host complement, and cell endocytosis
gal/galNAc-binding lectin
43
forms ion channels in the phagocytized bacteria and eukaryotic cells
amoebapores
44
trophozoites of a virulent strain of e. histolytica kills normal human polumorphonuclear neutrophils, monocytes, and macrophages in vitro
cytophagocytosis
44
symptomatic infections of e. histolytica
intestinal amoebiasis
- dysenteric
- nondysenteric colitis
extraintestinal amoebiasis
- hepatic (acute nonsuppurative & liver abscess)
- pulmonary
- other faci na rare
45
painful spasms of anal sphincter; sign of rectal ulceration
tenesmus
46
penetration of muscularis mucosae into the submucosa; flask-shaped ulceration
amoeba penetration
46
used to differentiate amoebic from bacillary dysentery
sigmoidoscopic examination
47
laboratory diagnosis of e. histolytica infection should be substantiated by
presence of RBC in the stool
serum antibody titer
stool e. histolytica antigen titer
48
routine diagnosis of e. histolytica / amoebiasis
microscopic examination
49
best way to diagnose e. histolytica is by a combination of __ and __
stool antigen detection; serology
50
serologic techniques
iha
elisa
eia
pcr
51
staining used to locate organisms within the tissues
periodic-acid shift (PAS)
52
allows accurate morphological demonstration of trophozoites
hematoxylin and eosin staining
53
countries where e. histolytica is most prevalent
SE Asia, SE and W Africa, Central and South America
54
e. histolytica and e. dispar infection is observed in __
men who have sex with men
54
how can cysts be killed even though they are resistant
by drying, by temperatures over 55C, by superchlorination / addition of iodine
55
treatment for invasive disease
metronidazole / tinidazole
56
treatment for intestinal (luminal) infection
paromomycin
diloxanide furoate (furamide)
56
first line treatment of hepatic abscess
metronidazole / tinidazole
57
water can be readily disinfected by __ and __
boiling; treatment with iodine
57
who proposed that e. histolytica is a complex specie
emile brumpt (1925)
57
t/f
e. histolytica is a noninvasive specie, while e. dispar and e. moshkovskii are invasive
f (other way around)
58
capable of causing focal intestinal lesions in experimental animals
e. dispar
58
nine times more prevalent than e. histolytica
e. dispar
59
detection rates and specificity have been greatly improved by __
PCR assays
59
dispar means __
different
59
[e. hartmanni]
size
troph:
cyst:
3-12; 4-10
59
t/f
e. hartmanni ingest bacteria and RBC
f (bacteria lang, no RBCs ingested)
59
[e. coli]
size
troph:
cyst:
15-50; 10-35
60
[e. coli: t]
motility
sluggish, nondirectional, nonprogressive;
61
nucleus of histolytica (cyst)
4 nuclei
62
[e. coli]
nucleus
troph:
cyst:
1; 8
63
karyosome of e. coli
large, irregular-shaped, eccentric
63
cytoplasm: finely granular with few bacterial inclusions and debris
e. histolytica
63
cytoplasm: granular, frequently containing many vacuoles (contains bacteria)
e. coli
63
shape of chromatoidal bodies in e. coli
splinter-shaped, rarely ribbon / thread-like, witchbroom
63
first parasitic amoeba described in humans
e. gingivalis
63
multiplies in bronchial mucus; appears in the sputum (commonly mistaken for e. histo)
e. gingivalis
64
e. gingivalis is most frequently recovered from mouths of patients suffering from __
pyorrhea alveolaris
64
[e. gingivalis]
size
5-15
65
t/f
e. gingivalis forms cysts
f (no cyst sis!)
65
e. gingivalis is the only species that ingests __
nuclear fragments from the leukocytes
65
cytoplasm may contain bacteria and occasional red cells; frequently filled with portions of ingested leukocytes
e. gingivalis
66
pseudopodia of e. gingivalis is
lobose, long, and blunt
67
e. gingivalis nucleus and karyosome:
mononucleated; small central
67
first reported as intestinal parasite of pigs and monkeys
e. polecki
67
organism morphologically identical to e. polecki
e. chattoni
68
[e. polecki]
nucleus
troph:
cyst:
single (occasionally visible); single (rarely binucleate/quadrinucleate
68
t/f
iodamoeba and endolimax are pathogenic and requires treatment
f (nonpathogenic; does not require treatment)
68
molecular techniques including __ and __ are widely utilized for accurate diagnosis of entamoeba species
polymerase chain reaction; nucleotide sequencing
69
cyst of __ are usually larger than those of __ and __
entamoeba; endolimax/iodamoeba
70
shape of endolimax
spherical / ovoid
71
shape of iodamoeba
irregular shape
71
single nucleus seen at one side of glycogen vacuole
iodamoeba butschlii
71
"basket nucleus" (for both troph and cyst)
iodamoeba butschlii
71
has prominent glycogen vacuoles
iodamoeba butschlii
71
[i. butschlii]
size
troph:
cyst:
9-14; 6-16
71
[i. butschlii: t]
motility
sluggish, nonprogressive;
72
[i. butschlii]
karyosome
troph:
cyst:
large, more or less central, irregularly rounded; eccentric
73
iodamoeba butschlii cyst
mononucleated
74
large glycogen vacuole distinct in the cytoplasm
iodamoeba butschlii
75
cyst prone to collapse (bc of large glycogen vacuole
iodamoeba butschlii
75
most common of the smaller intestinal amoeba
e. nana
75
[e. nana]
size
troph:
cyst:
5-12 both
75
cytoplasm contains food vacuoles with ingested bacteria
e. nana
75
GAE is caused by __
acanthamoeba
75
concentration that shrinks the cytoplasm of e. nana
zinc sulfate concentration
75
acute, fulminant, rapidly infection involving the CNS
primary amoebic meningoencephalitis (PAM)
75
observed as human symbionts
free-living amoeba
75
PAM is caused by __
naegleria
75
acanthamoeba belongs to family
acanthamoebidae
75
ovoid / spherical cyst
e. nana
75
amoeboflagellates able to temporarily assume a flagellate form while being completely devoid of flagella in the amoeboid stage
family vahlkamfiidae
75
never produce flagella
family acanthamoebidae
76
[e. nana]
karyosome
large, central / eccentris
76
naegleria belongs to family
vahlkampfiidae
77
more chronic and are associated among immunodeficient individuals
Granulomatous amoebic encephalitis (GAE) or Granulomatous amoebic meningoencephalitis (GAE)
77
brain-eating amoeba
naegleria fowleri
78
t/f
trophozoites and cysts occur in tissues in naegleria infections, while only trophozoites appear in tissues in acanthamoeba and balamuthia infections
f (trophozoites only - naegleria; trophozoites and cysts - acanthamoeba and balamuthia)
78
who first recognized the disease caused by n. fowleri
dr. malcom fowler
78
life cycle stages of n. fowleri
trophozoitie, flagellated, cyst
78
n. fowleri access the cns of the host through __
inhalation
79
2 forms of n. fowleri trophozoite
amoeboid and flagellated
80
[n. fowleri]
size
troph (a):
troph (f):
cyst:
7-35; 7-15; 7-15
80
[n. fowleri: t]
motility
a: sluggish
f: spinning / jerky
81
nucleus of n. fowleri (2t and c)
mononucleated
82
karyosome of n. fowleri (2t and c)
large, centrally located
82
two occasions where acanthamoeba is associated with human infection
CNS and corneal infection
82
fully active at room temp
n. fowleri
82
cytoplasm of n. fowleri (2t and c)
granular and vacuolated
82
at __ temp, maximum enflagellation occurs in __ to __ hours
37C; 4-5
82
drug of considerable toxicity used to treat PAM
amphotericin B
83
acanthamoeba infects __ when in contact with skin ulcerations / traumatic penetration
CNS
84
causative agents of GAE
acanthamoeba and balamuthia
85
first noted as contaminant in tissue cultures
acanthamoeba
86
produces lethal meningoencephalitis on nasal instillation into mice and other animals
acanthamoeba
87
ubiquitous, free-living amoeba found in air, soil, water, and dust
acanthamoeba
87
specie of acanthamoeba most often seen in cases of GAE and ocular infection
a. castellani
88
specie of acanthamoeba most often seen in cases of GAE
a. culbertsoni
88
specie of acanthamoeba most often seen in cases ocular infection
a. polyphaga
88
[acanthamoeba]
size
troph:
cyst:
15-45; 8-25
88
[acanthamoeba]
nucleus (t and c)
mononucleated
88
[acanthamoeba]
karyosome (t and c)
large, centrally located
88
[acanthamoeba]
cytoplasm (t and c)
granular and vacuolated
89
[acanthamoeba: t]
motility
spinelike pseudopodia
89
[balamuthia]
nucleus
troph:
cyst:
more than one nucleoli; mononucleated
89
[balamuthia]
size
troph:
cyst:
12-60; 13-30
90
[balamuthia: t]
motility
broad pseudopodia
90
3 layers of balamuthia cyst
ectocyst, mesocyst, inner thin endocyst
91
most probably occurs by way of the lungs or through invasion of CNS by hematogenous spread
GAE
91
chronic infection of cornea caused by several species of acanthamoeba
acanthamoeba keratitis
92
