MT 26 (LAB): FREE LIVING AMOEBA

facultative

free living amoebas are also parasitic - ______ parasites

opportunistic microorganisms

free living amoeba are described to be

soil and water

free living amoeba can be widely distributed in areas like

Naegleria fowleri, Acanthamoeba spp., Balamuthia mandrillaris

free living amoebas

Naegleria fowleri

it exists in amoeba form (trophozoite and cyst forms) and in a transient swimming flagellate stage

Naegleria fowleri

Pathogenic,a.k.a., brain-eating amoeba

Naegleria fowleri

The only amoeba that has 3 developmental stages (trophozoite, flagellates, cysts)

cyst

naegleria fowleri can also form a ____ if the environment is unfavorable

Trophozoite

Infective stage of naegleria fowleri

CNS

N. fowleri trophs invades the ____ of the body

flagellate form

in naegleria fowleri, the transition to ___ may help in rapid movement towards food

trophozoite stage of N. fowleri

single nucleus with large karyosome but with no peripheral chromatin

pseudopod

the amoeboid form of N. fowleri moves by means of

promitosis

• how does the trophozoite form of N. fowleri replicates?

• nuclear membrane remains intact

flagellate form of N. fowleri

pear shaped or elongated and has two anterior flagella

Flagellate form of N. fowleri

a temporary non-feeding stage that develops when trophozoites are exposed to a change in environmental conditions

cyst form of N. fowleri

spherical in shape with cell single nucleus same with trophozoite

soil and never in human tissue

cyst form in N. fowleri is found in?

Naegleria fowleri

Found in warm and hot freshwater environments such as ponds,lakes,rivers, hot springs, and poorly maintained swimming pools.

fresh water, soil, thermal discharges of power plants, geothermal wells, and poorly-chlorinated recreational and tap water

naegleria fowleri is found in areas like

Naegleria fowleri

Primary amoebic meningoencephalitis (PAM) is caused by

history of swimming in freshwater lakes or ponds or swimming pools

common historical experience to help diagnose for patients suffering from N. fowleri

nasal mucosa

point of entry for N. fowleri trophozoite

brain, olfactory nerves

Trophozoites infect humans or animals by penetrating the nasal mucosa, usually during swimming or sinus irrigation, and migrating to the ____ via the _____ causing primary amebic meningoencephalitis (PAM).

History of swimming in pools or natural warm water

CSF and Brain tissue biopsy examination

how to diagnose a person with N. fowleri

cyst stage

what stage is not seen under the CSF examination of N. fowleri

Trophozoite stage

what stage is seen under the CSF and brain tissue examination of N. fowleri

flagellate stage

what stage is seen only under the CSF examination of N. fowleri

spine or thorn

acantho means

Acanthamoeba spp.

ubiquitous free living amoeba

Acanthamoeba spp. can exist in areas like

• soil;

• fresh, brackish, and sea water;

• field-grown vegetables;

• sewage;

• swimming pools;

• contact lens supplies;

• medicinal pools;

• dental treatment units;

• dialysis machines;

• heating,

• ventilating, and

• air conditioning systems; and

• tap water;

• mammalian cell cultures

trophozoite and cyst

2 stages of Acanthamoeba spp.

flagellated stage

stage not seen in Acanthamoeba spp.

gram negative bacteria, algae, and yeasts

motile trophozoites in Acanthamoeba spp. feed on

contact lens cleaning solutions

Acanthamoeba spp. can also survive in products like

Trophozoite

Infective stage of Acanthamoeba spp.

Tissue

Where are the cysts and trophozoites of Acanthamoeba spp. found?

mitosis

Acanthamoeba spp. trophozoites replicate by ____?

eye

nasal passages then to lower respiratory tract

ulcerated or broken skin

trophozoite of Acanthamoeba spp. gains entry into the body by various means through the?

blood circulation

how come the effect of Acanthamoeba spp. travel from lungs to the brain?

CNS, eye, skin, and lungs

what organs of the man are affected because of Acanthamoeba spp.

Amebic Keratitis

direct contact of cornea with contaminated water or contact lens or lens solution

corneal scrapings

what test shall be done to diagnose patient with Acanthamoeba keratitis, where presence of trophozoites is seen

granulomatous amoebic encephalitis (GAE) and/or disseminated disease

when the Acanthamoeba enters the respiratory system or through the skin, it can invade the central nervous system by hematogenous dissemination causing ______

respiratory system, skin

when the Acanthamoeba enters the ___ ___ or through the ___, it can invade the central nervous system by hematogenous dissemination causing granulomatous amoebic encephalitis and/or disseminated disease in immunocompromised individuals

central nervous system

when the Acanthamoeba enters the respiratory system or through the skin, it can invade the ___ ___ ___ by hematogenous dissemination causing granulomatous amoebic encephalitis

granulomatous amebic encephalitis (GAE), disseminated disease, or skin lesions

Acanthamoeba spp. entering through ulcerated/broken skin causes what diseases in individuals with compromised immune systems?

headache

fever

nausea

altered mental status

signs and symptoms for granulomatous amoebic encepalitis

presence of cysts and trophs in CSF

Diagnostic stage of Acanthamoeba spp.

CSF exam

test to diagnose granulomatous amoebic encepalitis which may also show trophozoites and sometimes cysts

Balamuthia mandrillaris

free-living amoeba that causes the rare but deadly neurological condition granulomatous amoebic encephalitis (GAE)

Balamuthia mandrillaris

soil-dwelling amoeba

1986

B. mandrillaris was first discovered in ___ in the brain of a mandrill that died in the San Diego Wild Animal Park.

brain of a mandrill

In what animal is the B. mandrillas found?

open wounds, inhalation

B. mandrillaris can infect the body through____ or possibly by ____

Govinda Visvesvara

person who named the generic name Balamuthia

William Balamuth

• Visvesvara’s mentor parasitologist

• many contributions to the study of amoebae.

• influenced Visvesvara to name Balamuthia

1993

Visvesvara isolated and studied the Balamuthia for the first time in

cystic stage and non-flagellated trophozoite stage

• 2 life cycle stages of the Balamuthia mandrillaris

• both infectious

brain tissue; brain biopsies

The cystic and non-flagellated trophozoite stages can be identified through microscopic examination in the ___ ___ through ____?

pleomorphic and uninucleated

The Balamuthia trophozoite is ___ and ___, but binucleated forms are occasionally seen

FALSE, they are occasionally seen

The Balamuthia trophozoite binucleated forms are never seen in brain tissues (TRUE/FALSE)

Cyst of Balamuthia mandrillaris

• uninucleated

• possessing three walls:

  • ectocyst

  • mesocyst

  • endocyst

ectocyst, endocyst, mesocyst

3 walls of the Balamuthia cyst

ectocyst of balamuthia

wall of Balamuthia cyst: outer thin irregular

endocyst of balamuthia

wall of Balamuthia cyst: inner thick

mesocyst of balamuthia

wall of Balamuthia cyst: middle amorphous fibrillar

Balamuthia-induced GAE

can cause:

• focal paralysis

• seizures

• brainstem symptoms such as facial paralysis, difficulty swallowing, and double vision

focal paralysis, seizures, brainstem symptoms

Balamuthia-induced GAE symptoms

non-neurological symptoms; skin lesions

Balamuthia may also cause a variety of ______, including ___ ___, which can progress to GAE.

skin lesion

Patients experiencing this particular syndrome may report a __ ___ (often similar to those caused by MRSA), which does not respond well to antibiotics.

FALSE, it is localized, slow-healing, and may fail to heal altogether

Balamuthia skin lesions are usually fast-healing and always heal altogether (TRUE/FALSE)

skin cancer or cutaneous leishmaniasis

Some presentations of Balamuthia-induced infection can be mistake for certain forms of ____ or ____

FALSE, they are often painless

Balamuthia lesions are most often very painful (TRUE/FALSE)

Biopsies of skin lesions, sinuses, lungs, and the brain

detection of B. mandrillaris infection

FALSE, they do not eat bacteria

Balamuthia mandrillaris can be cultured on an agar plate coated with E. coli (TRUE/FALSE)

primate hepatocytes, human brain microvascular endothelial cells

Balamuthia must be cultured on ___ ___ or ___ ___ ___ ___.

Formalin-fixed paraffinized biopsy

specimens that may indicate Balamuthia trophozoites in the perivascular space.

calcofluor white

• binds to polysaccharides on the cyst wall.

• cysts can be visualized using this

circular

Balamuthia Trophozoites appear ____ during infection