Protozoan (parasitology)

3 generally considered nonpathogenic and reside in the large intestine of the human host

Entamoeba

Iodamoeba

Endolimax

2 locomotory organelles of protozoan

amoeba (pseudopodia)

flagellates

unicellular, microscopic organism belonging to any of several families of rhizopods that move and feed using pseudopodia and reproduce by fission

Amoeba

2 morphologic forms of amoeba

Trophozoites

Cysts

feeding stage, motile, sensitive, increased in wet samples

Trophozoite

non- feeding stage, infective stage, can survive in harsh environment

Cysts

belong in the phylum sarcomastigophoria

amoeba

Class of amoeba

Rhizopoda

Sarcodina

structure of amoeba

amoeboid (round shape)

3 main group of amoeba

Entamoeba

Naegleria

Acanthamoeba

life cycle of amoeba

Trophozoites stage > pre - cystic stage > cystic stage > metacystic stage

life cycle from cyst to trophozoites

excystation

life cycle from trophozoites to cyst

encystation

the only Entamoeba without cyst stage. it is also commensal

Entamoeba gingivalis

laboratory diagnosis in stool examination

saline

iodines

permanent staining

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stool examination for movement of troph

saline

stool examination for more detailed part

iodines

stool examination for confirmed identification

permanent staining

causative agent of amoebiasis ( amoebic dysentery -(bloody stool) an liver abscess

Entamoeba histolytica

characterized by vesicular nuclues with small central karyosome

Entamoeba

it is called that can be seen in intestine: Gastrointestinal tract

lumen dwelling

is the only parasite that can't be seen in gastrointestinal tract but it is found in mouth: oral cavity

Entamoeba gingivalis

species distinguishable to each other except

E. histolytica

E. dispar

E. moshkovskii

E. hartmanni

Entamoeba by molecular testing like isozyme analysis, PRC, and monoclonal antibody typing

E. histolytica

E. dispar

E. moshkoyskii

is known as the small race E. histolytica

Entamoeba Hartmanni

commensal (unable to cause infection) parasite

E. coli

E. hartamanni

E. dispar

E. moshkoviskii

E. gingivalis

Endolimax nana

Blastocystis hominis

Iodamoeba butschlii

pathogenic (causes disease) parasites

Entamoeba histolytica

free living parasites, the infections can be fatal, and penetrate blood brain barrier

Naegleria

Acanthamoeba

zoonotic parasite (also commensal) can be seen in monkeys

Entamoeba polecki

the only pathogenic amoeba, with surface galactose binding lectin that mediates attachment to host cell, 2nd leading cause of death after only malaria, may be transmitted through ingestion of food or water contaminated, with amoebapores- small polypeptide, may secrete cystein proteinase that play a key role in tissue invasion, invasion of last defense

Entamoeba histolytica

typically found in formed stool

Cysts

typically found in diarrheal stool

Trophozoites

infection for E. histolytica occurs by

ingestion of mature cysts in fecal contaminated food, water or hands.

can survive days to week in external environment and responsible for transmission

Cysts

passed in the stool are rapidly destroyed once outside the body, and if ingested would not survive

Trophozoites

E. histolytica is excystation that occurs in the _________________ and trophozoites are released which migrates to the ____________________

smaller intestine

large intestine

Trophozoites multiply by

binary fission

clinical symptoms of E. histolytica low virulence strain parasite, and intestinal amoebiasis is the most common form of infection and may be

asymptomatic

E.histolytica symptomatic, intestinal infection exhibiting abdominal discomfort ( flask shape ulceration in the colon) amoebic dysentery bloody and mucoid stool, symptoms of diarrhea, fever, abdominal pain, flatulence, weight loss, and fatigue

amebic colitis

most common form of extra- intestinal amoebiasis, symptoms of fever and right upper quadrant pain ( inflammation in liver) pulmonary amebic abscess ( lungs: sputum is sample) is recorded 2-3% of patient

amebic liver abscess

in amebiasis with abnormal mental status, (can be considered)

amebic meningoencephalitis

treatment for E. histolytica

mebendazole

paramomycin

diloxanide furoate

tetracycline with diiodohydroxyquin

prevention and control for E. histolytica

hand washing

drinking only clean water, if unsure, boil in first

washing of food products

do not use human feces as fertilizer, proper hygiene and sanitation

protect food away from cockroaches and flies

avoid unprotected sex.

facts about E. histolytica

E. histolytica is morphologically the same with E. dispar

the only difference is their DNA

use PCR to confirm the identification (erythrophagocytosis may also be used for differentiating)

parts of cysts

nucleus

central karyosome

vacuoles

chromatoidal bars/body

harmless, larger than E. histolytica, contains 1-8 nucleus but may reach up to 16 nucleus in large cyst

Entamoeba coli

morphologically similar to E. histolytica

Entamoeba dispar

smaller than E. histolytica does not contain RBC within the cytoplasm, measurement is very important "small race" E. histolytica

Entamoeba hartmanni

also considered a parasite of pigs and monkeys, cysts contains only 1 nucleus, prevalent in Papua, new guinea

Entamoeba polecki

cysts are spherical, ovoidal or ellipsoid contains 1-4 nucleus mostly 4 contains blot like karyosome

Endolimax nana

contains 1 nucleus and 1 large glycogen mass, the nucleus is said to be a basket of flower in shape.

Iodamoeba butschlii

may be found in the mouth, gum lines and gingival pockets, transmission is through kissing, droplets contamination and using contaminated utensils

Entamoeba gingivalis

causative agent of primary amebic meningoencephalitis

Naegleria fowleri

isolated first in sewages, osmotolerant (grown at room temperature of 25-30c and survives at 0-40c)

Entamoeba moshkovkii

brain eating amoeba

Naegleria fowleri

the three morphological form of Naegleria fowleri

amoeboid troph

flagellate

cysts

broad anterior, tapered posterior, are the known form that exist in human and seen when examining a CSF and or brain tissue specimen

Amoeboid trophozoites

has whip-like structure called flagella, may be rarely found in the CSF

Flagellates

round with thick cell wall and 1 nucleus

Cysts

specimen of choice in Naegleria fowleri

CSF-cerebrospinal Fluid

Naegleria fowleri infection starts when the amoeboid trophozoites enter the human body through

nasal mucosa

occurs when amoeboid trophozoites envades the brain causing rapid tissue destruction fever, vomiting, nausea etc., meningitidis is suspected if stiff neck and seizures occur, patients suffers taste attentions.

PAM- primary amebic meningoencephalitis

treatment for Naegleria fowleri

amphotericin B

a physically demonstrable symptom of meningitis

Kernig's sign

isolated locally morphologically indistinguishable from N. fowleri

Naegleria philippinensis

troph has a spinelike pseudopods, known as acanthaopodia, cyst has an outer jagged cell wall, can be seen in CSF but the ideal specimen is corneal scraping

Acanthamoeba spp. ( A. culbertsoni)

clinical symptoms of acanthamoeba spp.

Granulomatous amebic encephalitis

effects the CNS

includes headache, seizures, stiff neck, nausea and vomiting

no flagellates stage

acanthamoeba

infects cornea of the eye, severe ocular pain and impaired vision

Acanthamoeba keratitis

treatment for acanthamoeba keratitis

sulfamethazine (GAE)

keratitis - itraconazole, ketoconazole, miconazole, rifampin, clotrimazole

3 spp. of acanthamoeba

A. Castellani

A. culbertsoni

A. polyphaga

also causes GAE and is a free living amoebic does not have spiky pseudopodia

Balamuthia spp.

two spp. in. hemoflagellates

trypanosomal and leishmania

only ciliated protozoa, initially reported as paramecium coli, causes zoonotic disease called balantidiasis or balantidial dysentery, largest protozoan parasite and the only ciliated one, primary associated with pigs and dog found in Bolivia, Philippines, Papua new guinea

Balantidium coli

found in the tissue, muscles or blood

hemoflagellates

oval pointed anterior end, 50-130um long, covered in cilia, non-infective, binary fission, macro and micronuclei

trophozoites

morphological stage of hemoflagellates

Amastigote

Promastigote

Epimastigote

trypomastigote

spherical, covered with thick and hard cell wall, infective stage, macronuclei

cysts

two forms exist that are known to infect humans, found in the blood and cardiac tissue

trypanosoma spp.

treatment for balantidium coli

metronidazole

causative agent of Chagas, disease/American trypanosomiasis

vector: triatomid/triatomine bug or kissing bug and or reduviid bugs or assassin bugs, trypomastigotes assume a C or U shape in stained blood films

trypanosoma cruzi

inhabitant of lower gastrointestinal tract of human and other animals, formerly classified as yeast under genus schitzosaccharomyses transmitted via fecal oral route

blastocystis hominis

infective stage of trypanosoma cruzi

metacyclic trypomastigotes

main type of blastocystis causing diarrhea

blastocystis hominis

diagnostic stage of trypanosoma cruzi

C or S shaped trypomastigotes in the blood film and amstigotes

treatment for blastocystis hominis

mebendazole

mode of transmission in trypanosoma cruzi

entry of trypomastigotes in the bite site after scratching area; blood transfusion, kidney transplant

whip like flagella

flagellates

the current standard treatment for first stage disease in trypanosoma

IV. Pentamidine ( for TB. gambiense)

IV. Suramin ( for TB. rhodesiense)

majority of flagellates live in the small intestine and the blood except

Trichomonas tenax

trichomonas gingivalis

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Also known as T. brucei gambiense and T. brucei rhodesiense

causative agent of African sleeping sickness

vector: Tsetse fly of the genus glossina

Trypanosoma brucei

flagellates in intestine

Giardia intestinalis

Chilomastix mesnili

trichomonas hominis

dientamoeba fragilis

enteromonas hominis

retortamonas intestinalis

infective stage of trypanosoma brucei

injected metacyclic trypomastigotes during fly blood meal

all flagellates are commensals except

Dientamoeba

Giardia

diagnostic stage of trypanosoma brucei

trypomastigotes in blood

urogenital tract

trichomonas vaginalis

mode of transmission of trypanosoma brucei

tsetse fly bites and accidental needle pricks

blood and tissue

leishmania spp.

trypanosoma spp.

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pathogenesis

african sleeping sickness

winter bottom sign

kerandel sign

somnolence

chancre on bite site