protozoa amoeba flagellates sporozoa - pametnorcal.org · - cyst or trophozoite in stool -...

Protozoa

Amoeba

Flagellates

Sporozoa

Protozoa: Amoebas

∙ Locomotion

- Pseudopodia

∙ Mostly free-living

- Inhabit fresh water

- Some cause disease

1. Naegleria fowleri

2. Acanthamoeba

3. Balamuthia

∙ Obligate parasites of human GI

- Entamoeba, Endolimax, Iodamoeba

- Entamoeba histolytica regularly causes disease

Entamoeba histolytica

∙ Fecal-oral transmission

- Direct

- Indirect

∙ Risk factors

- Poor personal hygiene

- Gay men (oral-anal-sex)

- Poor sanitation

Protozoa/Amoeba

Diagnostic Assays for E. histolytica

∙ Microscopy

∙ Antigen detection

∙ E. HISTOLYTICA

∙ QUIK CHEK; TechLab

∙ NAATs

∙ Luminex xTAG® GI Pathogen Panel

∙ BioFire FilmArrayTM GI Panel

∙ Culture

∙ Serology

Entamoeba histolytica

E. histolytica/dispar trophozoites

Iodine 1000x Trichrome 1000x

Trichrome 1000x Trichrome 1000x

RBC

E. histolytica in Liver Abscess

H&E 600x

- ribosomal clusters

Entamoeba histolytica/dispar cysts

Trichrome 1000x Iodine 1000x

Entamoeba coli trophozoite

E. coli E. histolytica


Entamoeba coli cysts

Iodine 1000x

Diagnostic Challenges of E.histolytica

∙ Entamoeba dispar

- Morphologically identical to E. histolytica

- Differentiated with isoenzymatic, immunological,

or NAATS methods

∙ Entamoeba coli

- Cysts have ≥4 nuclei

∙ Entamoeba hartmanni, E. gingivalis

∙ Endolimax nana

∙ Iodamoeba beutschlii

Protozoa: Flagellates

∙ Locomotion

- Flagellum (rapid motility)

- Sucking disk

∙ Luminal flagellates

- Gastrointestinal

- Giardia intestinalis

- Dientamoeba fragilis

- Genitourinary

- Trichomonas vaginalis

∙ Blood and tissue flagellates

- Leishmania

- Trypanosoma

Pathogenic Flagellates

Giardia intestinalis

∙ #1 intestinal parasite in the US; ‘Beaver Fever’

∙ Fecal-oral transmission

- Direct

- Indirect

∙ Risk

- Poor personal hygiene

- Gay men (oral-anal-sex)

- Poor sanitation

Diagnostic Assays for Giardia intestinalis

∙ Microscopy

- Cyst or trophozoite in stool

- Trophozoite in jejunal biopsy

∙ Antigen detection (EIA)

∙ NAATs

- Luminex xTAG® GI Pathogen Panel

- BioFire FilmArrayTM GI Panel

Flagellates

- 10-20 um in length



Trichrome 1000x

Flagellates


Trichrome 1000x

Flagellates


Iodine 1000x

Dientamoeba fragilis Flagellates


Trichrome 1000x

Protozoa: Sporozoa

Habitat

- Obligate intracellular parasites

Reproduction

- Alternating asexual (schizogony)

and sexual (sporogony)

∙ Intestinal

- Cryptosporidia

C. parvum

C. hominis

- Cyclospora cayetanensis

- Isospora belli

∙ Blood and tissue sporozoa

- Plasmodia

- Toxoplasma gondii

Diagnostic Assays for Intestinal Sporozoa

∙ Microscopy

- Phase contrast microscopy

- Fluorescence microscopy

- Modified acid fast stain

- DFA

∙ Antigen detection (EIA)

- Superior to microscopy

∙NAATs

- Luminex xTAG® GI Pathogen Panel

- BioFire FilmArrayTM GI Panel

Sporozoa

Cryptosporidium parvum

Sporozoa

Modified AFB 1000x

Cryptosporidium

DF

A

1000x

Sporozoa

Microsporidia

Diagnostic Specimens & Tests

❑ CSF (Never refrigerate if parasite suspected)

• Direct wet preparation for motile trophs

• Concentrate material and examine

• Culture on lawn of E. coli

Naegleria

fowleri cyst &

trophs

Compliments of Dr. G. Visvesvara, CDC

• Patient developed severe ulcer on right

cornea upon removing his soft contact

lenses after an overnight drunk

Eye - scraping

TROPHOZOITE

Wet Prep for Acanthamoeba

CYS

T Compliments of Dr. G. Visvesvara, CDC

Trichomonas – wet preparation or culture

Trichomonas – wet preparation or culture

Culture only 50% sensitive vs PCR

protozoa amoeba flagellates sporozoa - pametnorcal.org · - cyst or trophozoite in stool -...

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