PROTOZOA (AMOEBA) Flashcards
(157 cards)
1
Q
A unicellular organism that performs all the functions: reproduction, digestion, respiration, excretion, etc.
A
Protozoa
2
Q
What Proto and Zoa means?
A
Proto = first
Zoa = animals
3
Q
Composition of Protozoa
A
❖ Nucleus
❖ Cytoplasm
❖ Structure for locomotion (Pseudopodia, Flagella, Cilla, Undulating membrane)
❖ Plasma membrane
❖ Cytostome
❖ Chromatoidal bodies
4
Q
A composition that is usually a single but may be double or multiple; contains one or more nucleoli or a central karyosome; DNA containing body 2.
A
Nucleus
5
Q
2 types of cytoplasm
A
❖ Endoplasm
❖ Ectoplasm
6
Q
A cytoplasm that is inner (often granulated), dense part.
It is granulated because it shows a number of structures such as Golgi bodies, endoplasmic reticulum, food vacuoles, and contractile vacuoles.
A
Endoplasm
7
Q
A structure that regulate osmotic pressure between the parasite and its environment.
A
Contractile vacuole
8
Q
A type of cytoplasm that is outer (non-granulated), typically watery
It is homogenous and serves as an organ for motility and engulfment of food by producing pseudopodia
It also helps in respiration, discharging waste material and providing protective covering.
A
Ectoplasm
9
Q
Differentiate the structures for locomotion
A
❖ Pseudopodia: fingerlike
❖ Flagella: Tail-like
❖ Cilla: Hair-like
❖ Undulating membrane
10
Q
Controls secretions and excretions.
A
Plasma membrane
11
Q
It is considered as a cell mouth.
A
Cytostome
12
Q
Storage for glycogen protein
A
Chromatoidal bodies
13
Q
Classification of Protozoan Parasites
A
Phylum Sarcomastigophora
Phylum Ciliophora
Phylum Apicomplexa
Phylum Microspora
14
Q
Intestinal and Extraintestinal Amoeba
A
Phylum Sarcomastigophora
Phylum Ciliophora
15
Q
2 Group of Parasite of Phylum Sarcomastigophora
A
Subphylum Sarcodina
Subphylum Mastigophora
16
Q
Subphylum Sarcodina parasite
A
Acanthamoeba
Endolimax nana
Entamoeba coli
Entamoeba dispar
Entamoeba gingivalis
Entamoeba histolytica
Iodamoeba butschliii
Naegleria fowleri
17
Q
Subphylum Mastigophora parasite
A
Chilomastix mesnii
Dientamoeba fragilis
Giardia lamblia
Trichomonas hominis
Trichomonas vaginalis
18
Q
Phylum Ciliophora
A
Balantidium coli
19
Q
Phylum Apicomplexa parasites
A
Babesia spp.
Cryptosporidium hominis
Cyclospora cayetanensis
Isospora belii
Plasmodium spp.
Toxoplasma gondii
20
Q
Phylum Microspora parasites
A
Enterocytozon bineusi
Encephalitozoon spp.
Vittaforma cornea
Pleistophora spp.
Brachiola vesicularum
Microsporidium spp.
21
Q
Stage forming a cyst or becoming enclosed to a capsule, this event takes place in the rectum of the host as feces are dehydrated or soon after the feces have been excreted.
A
Encystation
22
Q
Escape from cyst or envelope, produces a trophozoite from the cyst stage, and it takes place in the large intestine of the host after the cyst has been ingested.
A
Encystation
23
Q
All Entamoeba are commensal except
A
Entamoeba histolytica
24
Q
Finger-like structures for movement formed by sudden jerky movements of the ectoplasm in one direction.
A
With pseudopodium (false feet)
25
Undergoes ENCYSTATION except
Entamoeba gingivalis Dientamoeba fragilis
26
E. gingivalis and .fragilis do not have what form and stays at what form?
They do not have cyst form and stay in trophozoite form.
27
Inhabits the large intestine except
E. gingivalis (gums)
28
Presence of amoeba in any part of the body (exclusively applied to E. histolytica).
Amebiasis
29
Asexually multiplies through
Binary fission
30
Morphologic forms
1. Trophozoite
2. Pre-cyst
3. Cyst
4. Metacyst
31
Form that divides through "binary fission", capable of encystation (overpopulation, pH change, food supply, availability of oxygen) ∙
It undergo encystation in intestinal lumen or rectum.
Trophozoite
32
A form that contains large glycogen vacuole and two chromatid bars and then secretes a highly retractile cyst wall around it and becomes cyst.
Pre-cyst
33
Form with protective thick cell wall (hyaline), capable of excystation ∙ Cyst found on contaminated food and water could withstand the acidic pH of our stomach because of its thick cell wall made up of hyaline.
Cyst
34
A form that is liberated quadrinucleate amoeba during excystation ∙ No morphologic difference among other Entamoeba spp. such as E. moshkovskii and E. dispar. However, they can be differentiated through isoenzyme analysis, PCR, and monoclonal antibody typing.
Metacyst
35
Infective stage
Mature quadrinucleate cyst passed in feces
36
Mode of Transmission
❖ Ingestion of contaminated food and/or water with E. histolytica cyst.
❖ Fecal-oral (Primary route)
❖ Venereal transmission
❖ Direct colonic inoculation through contaminated enema equipment.
37
Trophozoite
❖ Vegetative and motile stage (feeding stage)
❖ Found in fresh watery, soft or semi-formed stool
❖ Fragile
38
Cyst
❖ Non-motile, feeding stage
❖Found in soft to formed stool
❖ Resistant to acidic pH
39
Life cycle of E. Histolytica and E. coli
Trophozoite
Cysts
40
TROPHOZOITE
MOVEMENT of E. Histolytica and E. coli
E. histolytica: Unidirectional,
progressive
E. coli: Sluggish, non
progressive and non directional
41
TROPHOZOITE
SHAPE OF PSUEDOPODIA of E. Histolytica and E. coli
E. histolytica: Finger-like
E. coli: Blunted
42
TROPHOZOITE
MANNER OF RELEASE OF PSUEDOPODIA of E. Histolytica and E. coli
E. histolytica: One at a time/explosive
E. coli: Several at a time
43
TROPHOZOITE
NUCLEUS of E. Histolytica and E. coli
E. histolytica: Uninucleated
(central karyosome)
E. coli: Uninucleated (eccentric karyosome)
44
TROPHOZOITE
INCLUSION of E. Histolytica and E. coli
E. histolytica: RBC
E. coli: Bacteria, yeast, debris
45
TROPHOZOITE
CYTOPLASM of E. Histolytica and E. coli
E. histolytica: Clean looking
E. coli: Dirty looking
46
TROPHOZOITE
SIZE of E. Histolytica and E. coli
E. histolytica: Bigger
E. coli: Smaller
47
CYST
NUMBER OF NUCLEI of E. Histolytica and E. coli
E. histolytica: Quadrinucleated (4)
E. coli: More than 4
48
CYST
CHROMATOIDAL BAR of E. Histolytica and E. coli
E. histolytica: Sausage, rod, cigar shaped
E. coli: Broomstick,
splinter-like
49
CYST
NUCLEAR MEMBRANE of E. Histolytica and E. coli
E. histolytica: Thin (10-15um)
E. coli: Thick (10-35 um)
50
Symptoms of having E. histolytica
∙ Gradual onset of abdominal pain
∙ Diarrhea (with or without blood)
∙ In children: bloody diarrhea, fever and abdominal pain.
∙ Abscess formation > Amoebic liver abscess
51
Pathology (Intestinal amebiasis)
Amoebic dysentery
Bacillary Dysentery
52
ONSET of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: Gradual
Bacillary Dysentery: Acute
53
SIGNS AND SYMPTOMSof Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: No significant fever or vomiting
Bacillary Dysentery: No significant fever or vomiting
54
ODOR OF FECES of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: Offensive, Fishy odor
Bacillary Dysentery: Odorless
55
BLOOD AND MUCUS of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: POSITIVE(+)
Bacillary Dysentery: Often watery and bloody
56
pH of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: Acidic
Bacillary Dysentery: Alkaline
57
PUS CELL/PMN/NEUTROPHILS of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: Few
Bacillary Dysentery: Numerous
58
CELLULAR EXUDATES of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: Scant
Bacillary Dysentery: Massive
59
PYKNOTIC RESIDUES of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: NUMEROUS
Bacillary Dysentery: FEW
60
CHARCOT LEYDEN CRYSTALS of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: PRESENT
Bacillary Dysentery: ABSENT
61
PATHOLOGIC AMOEBA of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: PRESENT
Bacillary Dysentery: ABSENT
62
BACTERIA of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: FEW
Bacillary Dysentery: NUMEROUS
63
MACROPHAGES of Amoebic dysentery and Bacillary Dysentery
Amoebic dysentery: ABSENT
Bacillary Dysentery: PRESENT
64
Common associated disease
❖ Intestinal amebiasis
❖ Amebic colitis
❖ Amebic dysentery
❖ Extraintestinal amebiasis
65
Gradual onset of abdominal pain and diarrhea with or without blood and mucus on the stool.
Amebic colitis
66
Mass-like lesions with abdominal pain and history of dysentery. It may be mistaken for carcinoma or malignant tumor.
Can cause ulceration "flask-shaped ulcer" in the intestines (cecum, ascending colon and sigmoid)
Ameboma
67
Pathogenic Determinants or Virulence Factor
1. Galactose-inhibitable adherence lectin (Gal Lectin)
2. Amoeba ionophore
3. Cysteine proteinase
68
Receptor mediated adherence of amoeba to target cells.
Galactose-inhibitable adherence lectin (Gal Lectin)
69
Cell lysis and tissue invasion ∙ Ionophore can attract calcium (anion), the calcium helps the Gal lectin so the parasite can adhere on the target cells.
Amoeba ionophore
70
Most important, tissue invading factor.
Cysteine proteinase
71
Through the portal vein (liver), trophozoite reach other parts of the body (liver, brain, lungs and kidneys).
EXTRAINTESTINAL AMOEBIASIS
72
Involvement of distant organs by hematogenous spread or through lymphatic resulting to abscesses in the kidney, brain, spleen, and adrenals
METASTATIC AMOEBIASIS
73
METASTATIC AMOEBIASIS DISEASES
∙ Amoebic hepatitis
∙ Amoebic liver abscess peritonitis
∙ Pulmonary amoebiasis
∙ Cerebral amoebiasis
∙ Splenic abscess
∙ Cutaneous amoebiasis
∙ Genitourinary amoebiasis
74
Repeated invasion in the
liver can cause inflammation.
AMOEBIC HEPATITIS
75
Most common
extraintestinal form of amoebiasis; fever, upper
right quadrant pain; thick chocolate brown pus
(liquefied necrotic liver tissue).
AMOEBIC LIVER ABSCESS
76
Destructive
ulcerative lesions may resemble carcinoma.
GENITOURINARY AMOEBIASIS
77
Asymptomatic carriers of E. histolytica
Cysts becomes unnoticed, ameba reproduce but infected individual shows no clinical symptoms.
78
Diagnostic Stage of E. histolytica
Identification of the cyst or trophozoite
79
Sample for Identification of E. histolytica
STOOL (examined within 30 minutes from collection)
80
Laboratory Diagnosis of E. histolytica
1. Direct Fecal Smear
2. Concentration Techniques
3. Culture
4. Serologic Testing
5. Molecular Testing
81
Standard method of parasitological diagnosis.
Microscopic detection of cyst and trophozoite
82
Number of stool sample to be examine
Minimum of 3 stools specimen on different days should be examined (one stool sample for each day)
83
Sample for the detection of trophozoite
Fresh stool specimen should be examined 30 mins after defecation.
84
Diagnostic of amebiasis.
Detection of E. histolytica trophozoite with ingested RBC under saline solution.
85
In Direct Fecal Smear, Saline Solution is for the detection of
trophozoite motility
86
In Direct Fecal Smear, Saline + methylene blue is for the detection of
Entamoeba spp. stain blue (differentiate Entamoeba spp. from WBC)
87
In Direct Fecal Smear, Saline + iodine is for the detection of
Nucleus of E. histolytica can be observed (differentiate E. histolytica from nonpathogenic amoeba)
88
In case of light infection, cyst and trophozoite may not be detected in direct fecal smear.
Concentration Techniques
89
2 types of Concentration Techniques
1. Formalin Ether/ Ethyl Acetate Concentration Technique (FECT)
2. Merthiolate Iodine Formalin
Concentration (MIFC) – Sedimentation technique
90
More sensitive than stool microscopy but not routinely available.
Culture
91
Types of Serologic Testing
ELISA (Enzyme-linked Immunosorbent Assay)
CIE (Counter Immunoelectrophoresis)
AGD (Agar Gel
Diffusion)
IHAT (Indirect Hemagglutination Test)
IF-AT (Indirect Fluorescent Antibody Test)
92
Considered as gold standard in detecting E. histolytica infection.
IHAT (Indirect Hemagglutination Test)
and IF-AT (Indirect Fluorescent Antibody Test)
93
Technique for molecular testing
PCR
94
In case f extraintestinal amoeba, what technique can be used to be used to detect amebic liver abscess.
CT-scan and MRI
95
Treatment used to cure invasive disease at both intestinal and extraintestinal site and to eliminate passage of cyst from intestinal lumen.
Metronidazole
Diloxanide furoate
Percutaneous drainage of the liver abscess
96
Drug of choice for invasive amebiasis.
Metronidazole
97
Secondary medicine for invasive amebiasis
Tinidazole and secnidazole
98
Drug of choice for asymptomatic cyst passers.
Diloxanide furoate
99
Patients who do not respond to metronidazole and need prompt relief of severe pain.
Percutaneous drainage of the liver abscess.
100
Prevention and Control
❖ Proper hygiene
❖ Provision for sanitary disposal of human feces
❖ Improve access to clean and safe drinking water
❖ Good food preparation practices
❖ Avoid using "night soil"
❖ Food handler should be examined for cyst carriage
❖ Health education and promotion
101
Non-Pathogenic species
1. Entamoeba coli
2. Entamoeba dispar
3. Entamoeba
4. Entamoeba polecki
5. Entamoeba gingivalis
6. Entamoeba moshkovskii
7. Endolimax nana
8. Iodamoeba butschlii
102
Harmless inhabitant of the colon.
Entamoeba coli
103
CYST SIZE of Entamoeba coli
10 - 35 um (larger than E. histolytica)
104
CYSTS NUCLEI of Entamoeba coli
Has 8 nuclei with very diffuse karyosomes, may become hypernucleated with 16-32 nuclei
105
CYST CHROMOTOIDAL BODIES of Entamoeba coli
Irregular fragmented
Sharp
Splintered ends
106
TROPHOZOITE SIZE of Entamoeba coli
15-50 um (Smaller than E. histolytica)
107
TROPHOZOITE NUCLEUS of Entamoeba coli
1 nucleus containing diffuse karyosome.
108
TROPHOZOITE PERIPHERAL CHROMATIN of Entamoeba coli
Usually dense and irregular
109
TROPHOZOITE CYTOPLASM of Entamoeba coli
Usually rough and contain few to many ingested debris.
110
MOTILITY OR MOVEMENT of Entamoeba coli
E. coli: Sluggish, non
progressive and non directional
111
PSEUDOPODIA of Entamoeba coli
Short and blunt
Granular
Slowly extruded
112
INCLUSIONS of Entamoeba coli
Bacteria and other material
No RBCs ingested
113
NUCLEUS of Entamoeba coli
Rarely visible
114
NUCLEAR MEMBRANE of Entamoeba coli
Thick
Lined with coarse chromatin dots and bars
115
KARYOSOME of Entamoeba coli
Large
Location is ECCENTRIC
Surrounded by a halo of non-staining material.
116
Morphologically similar to E. histolytica, but with different DNA and RNA.
Entamoeba dispar
117
Similar to E. histolytica except much smaller and no RBC inclusions
"small-race E. histolytica
Entamoeba hartmanni
118
Parasite of the pigs and monkeys (rarely infect humans).
Humans are accidental/incidental host.
Entamoeba polecki
119
found in apes and monkeys, identical to E. polecki, identification via ISOENZYME ANALYSIS.
Entamoeba chattoni
120
Not capable of encystation. Trophozoite form only.
Can be found in the mouth (gum and teeth surfaces).
Abundant in cases of oral diseases.
No cyst stage, does not inhabit the intestines.
May ingest RBC (rarely), associated on lesions inside the mouth.
Entamoeba gingivalis
121
Mode of transmission for Entamoeba gingivalis
Through kissing
Droplet spray
Sharing utensil
122
Morphologically indistinguishable from those of the disease causing species E. histolytica and the non-pathogenic E. dispar, but differs from them biochemically and genetically.
Although sporadic cases of human infection with this parasite have been reported, the organism is considered primarily a free-living amoeba.
Entamoeba moshkovskii
123
Physiologically uniqueness of Entamoeba moshkovskii
Osmotolerant, able to grow at room temperature and able to survive at 0-41C
124
"Smallest amoeba"
"Cross eyed cyst" — 4 eccentric nuclei
Blot-like karyosome
Endolimax nana
125
"iodine-cyst" because of its affinity to iodine.
Large glycogen vacuole/ body which stains deeply with iodine.
Uninucleated — resembling a "basket of flowers" shape
Iodamoeba butschlii
126
MOTILITY of Iodamoeba butschlii
Sluggishly progressive
With hyaline pseudopodia
127
INCLUSIONS of Iodamoeba butschlii
Bacteria scattered throughout the cytoplasm
RBCs are never ingested
128
NUCLEUS of Iodamoeba butschlii
Not visible
129
KARYOSOME of Iodamoeba butschlii
Large
Centrally located
Irregularly rounded
Surrounded by a layer of small granules
130
FREE LIVING PATHOGENIC AMOEBA
1. Acanthamoeba spp. (Acanthamoeba castellani)
2. Naegleria fowleri
131
Ubiquitous, free-living ameba
With an active trophozoite stage with characteristic prominent "thorn-like" appendages (acanthopodia) and resilient cyst stage
Aquatic organism, can survive in contact lens cleaning solutions
Most common ameba of freshwater and soil
Acanthamoeba spp. (Acanthamoeba castellani)
132
Mode of Transmission of Acanthamoeba spp. (Acanthamoeba castellani)
Aspiration and Nasal inhalation: Use of contaminated swimming pools, deep well, etc.
Direct invasion of the eye: contaminated saline
133
Specimen used for testing Acanthamoeba spp. (Acanthamoeba castellani)
Discharges
Exudates
Tissue secretions
134
Pathogenesis of Acanthamoeba spp. (Acanthamoeba castellani)
Granulomatous Amoebic Encephalitis (GAE)
Amoebic keratitis (contact lens users)
135
A destructive encephalopathy and associated meningeal irritation.
Disease of immunocompromised (AIDS)
Granulomatous Amoebic Encephalitis (GAE)
136
Laboratory Diagnosis of Granulomatous Amoebic Encephalitis (GAE)
made by demonstration of trophozoites and cysts in brain biopsy (post-mortem in most cases), culture, and immunofluorescence microscopy-using
monoclonal antibodies.
CSF shows lymphocytic pleocytosis (abnormal
increase in the number of lymphocyte in the CSF),
slightly elevated protein levels, and normal or
slightly decreased glucose levels.
CT scan of brain provides inconclusive findings.
137
It is a disease that has perforation of the cornea and results to subsequent loss of vision.
Amoebic keratitis (contact lens users)
138
Laboratory diagnosis of Amoebic keratitis
made by demonstration of the cyst in corneal scrapings by wet mount, histology, culture (growth can be obtained from corneal scrapings inoculated on nutrient agar, overlaid with live or dead Escherichia coli and incubated at 300 C), demonstration of cyst and trophozoites in stool and PCR.
139
Free-living protozoan with two vegetative forms: an ameba (trophozoite form) and a flagellate (swimming form)
"brain-eating amoeba"
Thermophilic organism that thrive best in hot springs and other warm aquatic environment.
True pathogen
Disease almost ends fatally within a week
Naegleria fowleri
140
Incubation period of Naegleria fowleri
ncubation period varies from 2 days to 2 weeks.
141
Pathologic disease of Naegleria fowleri that the patients initially complain of fever, headache, sore throat, nausea and vomiting.
Hemorrhagic necrosis in post mortem examination of infected brain.
Fatal Primary amoebic encephalitis (PAM)
142
It is a diagnostic sign for meningitis where the patient is unable to fully straighten his or her leg when the hip is flexed at 90 degrees because of hamstring stiffness.
"Kernig's sign"
143
Mode of transmission of Naegleria fowleri
Oral and intranasal routes while swimming in contaminated pools, rivers and lakes
144
Laboratory diagnosis of Naegleria fowleri
❖ CSF examination
∙ cloudy to purulent
∙ neutrophilic leukocytosis
∙ elevated protein and low glucose
∙ resembling pyogenic meningitis
❖ Wet film examination of CSF: (+) trophozoites
❖ Autopsy: (+) trophozoites in immunofluorescent staining
❖ Culture: can be grown in several kinds of liquid axenic media or non-nutrient agar plates coated with Escherichia coli, (+) both trophozoites and cysts.
❖ Molecular Diagnosis: Polymerase chain reaction (PCR)
145
Prevention for Naegleria fowleri
Frequent cleaning
Chlorination
Salination
146
PHYLUM CILIOPHORA
CILATES specie
Balantidium coli
147
Causative agent of "balantidiasis or balantidial dysentery", similar to amoebic dysentery.
Largest protozoan parasite.
Only parasitic ciliate.
Primarily associated with pigs.
It does not invade the liver or other extraintestinal site unlike E. histolytica.
Balantidium coli
148
Morphology of Balantidium coli
Has trophozoite and cyst stage
149
Parts of Blantidium coli
Cytosome: entry of food
Cytophyge: excretes waste
Two dissimilar nucleus: Large kidney-shaped macronucleus and micronuclei
One or two contractile vacuoles
150
Pathogenic determinants
Hyaluronidase
Ulceration
151
Causes the ulceration, secreted by trophozoite
Hyaluronidase
152
Described as flask-shaped ulcer but with rounded base and wider neck.
Ulceration
153
Laboratory diagnosis of Balantidium coli
Stool examination: microscopic demonstration of cyst and
trophozoite in direct.
Biopsy: specimens and scrapings from intestinal ulcers can be examined for presence of trophozoites and cysts.
Culture: can also be cultured in vitro in Locke's egg albumin medium or NIH polyxenic medium like Entamoeba histolytica, but it is rarely necessary.
154
Mode of transmission for Balantidium coli.
Ingestion of food/water contaminated with B. coli cyst
155
Infective stage for Balantidium coli.
Cyst
156
Treatment for Balantidium coli.
Tetracycline is the drug of choice.
Doxycycline alternatively can be given.
Metronidazole and Nitroimidazole have also been reported to be useful in some cases.
157
Prevention for Balantidium coli.
Avoidance of contamination of food and water with human or animal feces.
Prevention of human-pig contact.
Treatment of infected pigs.
Treatment of individuals shedding B. coli cysts.
