16 - non- pathogenic + pathogenic amoebae flagellates

non- pathogenic protozoia (NPP) - characteristics

• commensals

• order amoebida

list all 6 non- pathogenic protozoa

1. entamoeba coli

2. entamoeba hartmani

3. entamoeba polecki

4. endolimax nana

5. lodamoeba butschlii

6. entamoeba gingivalis

why ID NPPs?

• oral- fecal contamination

• potential infection w/ other pathogens

• avoid unnecessary treatment

entamoeba coli (NOT E. COLI!!!)

• most common intestinal amoebae

• often coexists w/ E. histolytica

entamoeba coli - trophozoite

• nucleus

  • PC = clumped

  • endosome = large, eccentric

• lives in LI

• does NOT invade tissue

entamoeba coli - young cyst

• 1, 2, 4 nuclei

• chromatoidal bars

• splintered ends

entamoeba coli - mature cyst

8 nuclei

entamoeba hartmani - morphology, troph, cyst

same morphology as E. histolytica, just smaller

• troph = 12-15 μm

• cyst = 5-9 μm

entamoeba polecki - morphology, troph, cyst

uninucleate = many bars

• troph = 10-20 um

• cyst = 10-20 um

endolimax nana - morphology, troph, cyst

very small

• troph = ~9 um

  • no PC

  • large, centric endosome

  • moves very slowly “dwarf internal slug”

• cyst = 4 nuclei

  • ~9 um

iiodamoeba butschlii - troph + cyst

• troph = ~10um

  • large endosome

• cyst = oval

  • uninucleate

  • large glycogen vacuole

    • stains w/ iodine

pathogenic free- living amoebae characteristics

does NOT ever need host

• normally free- living

• facultative parasitism

  • highly pathogenic

pathogenic free- living amoebae types

1. naegleria fowleri

2. acanthamoeba spp

naegleria fowleri characteristics

• order schizopyrenida

• worldwide

• troph enters nose when H2O forced in

naegleria fowleri activity after entering nose

• migrate along olfactory nerves into brain

• primary amoebic meningoencephalitis (PAM)

  • hemmorhage + necrosis of brain tissue

    • coma + death

naegleria fowleri - PAM

• rare, very serious

• mortality rate: 95% w/in 72 hrs

• early recognition + aggressive therapy

naegleria fowleri symptoms

• stiff neck

• headaches

• light sensitive

• fever

• seizure

naegleria fowleri diagnosis

• lumbar puncture: trophs in CSF

• antigen detection

• usually death before diagnosis

naegleria fowleri - treatment combination medicines

1. amphotericin B

2. rifampin

3. miconazole

naegleria fowleri - amphotericin B

antifungal

• binds, disrupts membrane, cytoplasm leaks out

naegleria fowleri - rifampin

antibiotic

• disrupts transcription (DNA → RNA)

naegleria fowleri - miconazole

antifungal

• mechanism unknown

naegleria fowleri - miltefosine

investigational

naegleria fowleri - therapeutic hypothermia

cooling below normal body temp

• lowers brain swelling

naegleria fowleri control

• caution in warm fresh water

• maintain pools

• blow nose forcefully

• careful when using neti pot

acanthamoeba spp characteristics

• order amoebida

  • soil + H2O

acanthamoeba spp step 1

cysts

acanthamoeba spp step 2

trophozoite

acanthamoeba spp step 3

mitosis

acanthamoeba spp step 4

trophozoites + cysts enter in various ways

acanthamoeba spp entry points

• eyes

• nose

• skin

acanthamoeba spp diseases

• granulomatous amoebic encephalitis (GAE)

• acanthamoebic keratitis

• skin lesions

acanthamoeba spp - GAE

trophs enter nose

• perivascular

  • CNS

    • damage (less severe than PAM)

acanthamoeba spp - acanthamoebic keratitis

• infection of cornea

• contact lenses

acanthamoeba spp diagnosis

trophs in CSF, skin, eye

acanthamoeba spp treatment

same as PAM

flagellates characteristics

• phylum metamonada

• flagella 

• human digestive + repro tissue

flagellates species

• giardia lambila

• trichomonas

giardia lambia characteristics

• giardiasis

• backpacker’s disease

• beaver fever

giardia trophozoite - basal bodies

give rise to flagella

giardia trophozoite - ventral flagella

4 pairs of flagella

giardia trophozoite - median body

• microtubules

• functions w/ ventral disc

giardia trophozoite - ventral disc

attachment

giardia trophozoite - nucleus

2 nuclei

giardia - cyst

• oval

• 4 nuclei

• short flagella inside

giardia life cycle - trophs 

• duodenum + bile duct

• trypsin → attachment to epithelial cells

• longitudal binary fission

• encyst

giardia life cycle - cyst

• transmission stage

• excyst in SI

giardia step 1

cysts + trophozoites passed in stool

• trophozoites DO NOT survive in ext env

giardia step 2

contamination of water, food or hands with cysts

• cysts ingested

giardia step 3

trophozoites active inside body

giardia step 4

trophozoites split to reproduce

giardia step 5

excyst otw to colon

giardia pathology

• flattened villi = nutrient malabsorption

• diarrhea = dehydration

• steatorrhea = fat malabsorption

  • fatty stool

giardia diagnosis

• cysts in feces

• direct immunoflorescence assay (DFA)

direct immunoflorescence assay (DFA)

antibodies tagged with florescent markers

• added to stool + incubated

  • visualization under fluorescent microscope

giardia treatment

metronidazole (flagyl)

• inhibits DNA synthesis

giardia prevention

• H2O treatment = sand filtration

• campers = infected individuals

  • treat them

trichomonas characteristics

• undulating membrane

• axostyle

• no mitochondria

• hyrogenosomes

• no cyst stage

trichomonas undulating membrane

recurrent flagellum: curves back + pulls PM

trichomonas axostyle

• microtubules

• motility + mitosis

trichomonas hyrogenosomes

• metabolism of pyruvate + ATP prod.

• end product is H2

trichomonas male pahology

usually asymptomatic

normal pH for vagina

4-4.5

• lactic acid- producing bacteria

trichomonas female pathology

trichomonad vaginitis

• feeds on bacteria + pH increases

  • optimal pH for trophs is 5-6

• inflammation of vaginal epithelium

• pain, itching and leucorrhoea

trichomonas transmission

• direct = sexual

• indirect = damp towel

• newborns = directly into eyes during birth

trichomonas diagnosis

female = trophs in discharge smears + urine

male = trophs in prostate secretions + urine

trichomonas treatment + prevention

metronidazole = both partners

condom