1all amoeba are commensal except
Entamoeba histolytica
2finger-like structures for movement
pseudopod
3undergoes encystation except
Entamoeba gingivalis and Dientamoeba fragilis
4inhabits the large intestine except
Entamoeba gingivalis (gums)
5presence of amoeba in any part of the body
Amoebiasis
6amoeba asexually multiplies through
binary fission
7THREE STAGES OF REPRODRUCTION
Excystation, Encystation, Binary Fission
8Development of cyst into trophozoite
Excystation
9Development of trophozoite into cyst
Encystation
10Mode of reproduction of trophozoite
Binary Fission
11described by Feder Losch - found mostly in tropical and subtropical areas
Entamoeba histolytica
12Divides through binary fission
Irregular shape
Motile (unidirectional)
Flask-shaped ulcer
Entamoeba histolytica Trophozoites
131-4 nucleus
Cigar-rod shaped chromatoidal body
Centrally located karyosome
Entamoeba histolytica Cyst
14Metacyst ineffective stage
Tetranucleated (mature cyst)
15Mode of transmission - Entamoeba histolytica cyst
Ingestion of contaminated food and/or
water
16 Vegetative and motile stage –
feeding stage. Found in watery, soft, or semi-
formed stool. fragile
Entamoeba histolytica Trophozoites
17Non-motile, non-feeding stage. Found in soft to formed stool. Resistant to acidic pH
Entamoeba histolytica Cyst
18State of being infected without showing symptoms, common in Entamoeba histolytica infections.
Asymptomatic Carrier State
19Symptoms
abdominal pain, Diarrhea..IN CHILDREN - bloody diarrhea, fever, and abdominal pain
201. The parasite is low-virulence strain
2. The inoculation into the host is low
3. The patient’s immune system is intact
Asymptomatic Carrier State - E. histolytica
21SYMPTOMATIC INTESTINAL AMEBIASIS
Amebic Colitis
(intestinal infection)
Amebic Dysentery
(blood & mucus in stool)
22Through the portal vein (liver), trophozoite reach other parts of the body
(liver, brain, lungs, kidneys)
Symptomatic Extraintestinal Amebiasis
23(Can cause Amebic liver abscess → anchovy sauce-like effusion)
Hepatic amebiasis
24PATHOLOGIC CONDITIONS OF AMEBIASIS
1. Hepatic amebiasis
2. Pulmonary amebiasis
3. Cerebral amebiasis
4. Amebic pericarditis
5. Cutaneous amebiasis
6. Genital amebiasis
25cause hepatomegaly or enlargement of liver
Amebic Liver Abscess (ALA)
26MOST COMMON COMPLICATIONS
Rupture in pericardium - 70% mortality rate
Rupture in pleura - 15-30% mortality rate
Superinfection - Infection after earlier infection
27SECOND MOST COMMON COMPLICATION
Intraperitoneal Rupture: 2-7.5% of cases is not serious as colonic perforation
28Can cause ulceration “flask-shaped ulcer” in the intestines:
• cecum
• ascending colon
• sigmoid
29Neutralizes stomach pH
Suppressor Factor
30Cytoadherence or cellular adherence
Gal/Gal Naclectin
31Poreformers - Form ion channels in phagocytize cells (result in
cell lysis)
Ameba pores
32Tissue invasiveness
- Degrading mucus and debris
Cysteine Proteinase
33Direct Fecal Smear
Saline Solution Trophozoite motility
Saline + Methylene Blue Entamoeba spp. stain blue
Saline + Iodine Nucleus of E. histolytica can be observed
34Concentration Technique
1. Formalin Ether Concentration Technique (FECT)
2. Merthiolate Iodine Formalin Concentration (MIFC)
3. 33% ZnSO4 Floatation Technique (SP 1.18 – 1.20)
35more sensitive than stool microscopy
Culture: Robinson’s and Inoki Medium
36Serological Testing
• ELISA
• IHAT – can detect past infection
• CIE
• AGD
• IFAT
37LABORATORY DIAGNOSIS
•Molecular Testing: PCR
•CT-Scan or MRI
38Drug of Choice For invasive amebiasis
Metronidazole
39Drug of Choice For asymptomatic cyst passer
Diloxanide furoate
40PREVENTION AND CONTROL
1. Proper hygiene
2. Provision for sanitary disposal of human feces
3. Improve access to clean and safe drinking water
4. Good food preparation practices
5. Avoid using “night soil”
6. Health education and promotion
41Harmless inhabitant of the colon
ENTAMOEBA COLI
42Morphologically similar to E. histolytica, but with different DNA and RNA
Entamoeba dispar
43Similar to E. histolytica except much smaller and no RBC inclusions
- “Small-race E. histolytica”
Entamoeba hartmanni
44Parasite of pigs and monkeys (rarely infect humans)
- Cyst contains one nucleus
Entamoeba polecki
45Found in apes and monkeys
- Identical to Entamoeba polecki
ENTAMOEBA CHATTONI
46Can be found in the mouth (gum and teeth surfaces)
- No cyst stage
Entamoeba gingivalis
47Physiologically unique
- Test RNA and DNA to differentiate
ENTAMOEBA MOSHKOVSKII
48Smallest amoeba
- Cross-eyed cyst
• 4 eccentric nuclei
Endolimax nana
49Large glycogen vacuole or body which stain deeply with iodine
- Chromatoidal bars are present
- Uninucleated cyst
Iodamoeba butschlii
50Acanthamoeba - Causative agent:
1) Granulomatis Amoebic Encephalitis (GAE)
2) Destructive Encephalopathy
3) Associated Meningeal Irritation
4) Amoebic keratitis (ocular infection)
51GAE
Acanthamoeba castellanii
Acanthamoeba culbertsoni
52Ocular Infection
Acanthamoeba polyphaga
531. Severe ocular pain and blurring
2. corneal ulcerations with progressive corneal infiltration
3. progression of infection may lead to scleritis and iritis
4. vision loss
Amoebic Keratitis
54Acanthamoeba keratitis have been successfully been treated with:
P - Propamidine isethionate
R - Rifampin
I - Itraconazole
M - Miconazole
K - Ketoconazole
55Brain eating amoeba
- Named in honor of Dr. Malcolm Fowler who first recognized the disease.
- Thermophilic organisms
Naegleria
56Is the only amoeba with three known morphologic forms
Naegleria fowleri
57Primary Amoebic Meningoencephalitis (PAM)
• Fever
• Nausea
• Vomiting
• Headache
• Mental status changes
• Rapid progression to coma
• Death
58• Defluxion of hips and spine which causes severe pain
Kernig’s Sign
59damage the cell wall of Naegleria
Amphotericin B and miconazole
60inhibits RNA synthesis in the amoeba
Rifampicin
61similar to amoebic dysentery
- largest protozoan parasite
- only parasitic ciliate
- primarily associated with pigs
Balantidium coli
62Described as flask-shaped ulcer but with wider neck and round base
Ulceration
63Causes ulceration
Hyaluronidase
64abscesses and ulcers may form in the mucosa and
submucosa of the large intestine, followed by
secondary bacterial infection.
Balantidiasis
65Balantidiasis - Symptomatic
1) mild colitis
2) diarrhea
3) full-blown clinical balantidiasis (resembles
amebic dysentery)
66characterized by up to 15 liquid stools daily containing pus, mucus, and blood.
Acute Infection (Fulminant Balantidiasis)
67may develop a tender colon, anemia, cachexia, and occasional diarrhea, alternating with constipation.
Chronic Infection (Chronic Balantidiasis)
68Balantidiasis Treatment
Metronidazole