ACANTHAMOEBIASIS

Question 1

is a genus of free-living amoebae widely distributed in the environment, commonly found in soil, freshwater, dust, and various man-made water systems.

Answer 1

Acanthamoeba

Question 2

Amoeba exist in two forms: ENUMERATE

Answer 2

1. Trophozoite
2. Cyst

Question 3

highly resistant, dormant stage or form of amoeba

Answer 3

cyst

Question 4

Acanthamoeba species primarily act as _______; however, under
certain conditions, especially in
immunocompromised individuals, they can become __________ capable of causing severe and potentially fatal diseases

Answer 4

bacterivores
opportunistic pathogens

Question 5

Acanthamoebiasis caused by Acanthamoeba may manifest in
different forms. ENUMERATE

Answer 5

1. Acanthamoeba keratitis
2. Granulomatous amoebic encephalitis (GAE)
3. Skin lesions

Question 6

The most commonly identified causative agents of Acanthamoebiasis. ENUMERATE

Answer 6

1. Acanthamoeba castellanii
2. A. polyphaga
3. A. culbertsoni
4. A. palestinensis

Question 7

This form of Acanthamoeba helps the organism survive harsh conditions;
can reactivate into trophozoites when conditions improve

Answer 7

Cyst

Question 8

Dormant, resistant stage, Double-walled structure, (Ectocyst: Outer wall & Endocyst: Inner wall), Slightly smaller than trophozoite, Highly resistant to: Disinfectants, Temperature extremes, Desiccation (drying)

Answer 8

Cyst

Question 9

This form of Acanthamoeba is sensitive to environmental stress (e.g., drying, extreme pH, chemicals)

Answer 9

Trophozoite

Question 10

Active and feeding stage, Moves using acanthopodia (spine-like pro
jections), Reproduce through binary fission (asexual), This is the form
that invades tissues and causes diseases

Answer 10

Cyst

Question 11

Acanthamoeba trophozoite moves using _________

Answer 11

acanthopodia (spine-like projections)

Question 12

Trophozoite (a form of Acanthamoeba) can be found in?

Answer 12

soil, freshwater, sea water, sewer water, brackish water, tap water, contact lens solution, air-conditioning units, vegetables

Question 13

Acanthamoeba reproduce through?

Answer 13

binary fission (asexual)

Question 14

Amoeba (cyst and trophozoite) can enter the body through?

Answer 14

✓ eye
✓ nasal passages to the LRT
✓ ulcerated or broken skin

Question 15

Infective stage of Acanthamoeba spp.

Answer 15

Trophozoite

Question 16

One of the clinical signs of Acanthamoebiasis which is rare, present subacutely/chronically and occurs in immunocompromised animals

Answer 16

Granulomatous Amoebic Encephaliti (GAE)

Question 17

One of the clinical signs of Acanthamoebiasis which occurs in healthy individual, primarily associated with contact lenses use, also associated with corneal trauma

Answer 17

acanthamoeba keratitis

Question 18

One of the clinical signs of Acanthamoebiasis which is associated with localized granulomatous inflammation, usually from broken skin contact but also seen in disseminated infections, hard nodules and
cutaneous ulcers

Answer 18

skin lesion

Question 19

Lesion: multifocal parenchymal lesion, pseudotumor, hemorrhagic infarct, necrosis

Symptoms:
headache
altered mental status
neurologic signs
stupor/ coma
death

Answer 19

GRANULOMATOUS AMOEBIC ENCEPHALITIS (GAE)

Question 20

symptoms:
foreign body sensation
photophobia
decreased visual acuity
excessive lacrimation
pain, redness

Answer 20

acanthamoeba keratitis

Question 21

is common in regions with poor water hygiene, uncontroled environmental conditions, and high contact lens usage

Answer 21

Acanthamoebiasis

Question 22

This specimen, if used in diagnosing acanthamoebiasis, detects both trophozoite and cyst

Answer 22

CSF

Question 23

acanthamoeba spp. can be cultured on this media

Answer 23

non-nutrient agar seeded with E. coli

Question 24

GRANULOMATOUS AMOEBIC ECEPHALITIS combination therapy

Answer 24

pentamidine
sulfudiazine
fluconazole/itraconazole
cotrimoxazole + nifampin
miltefosine
miltefosine + voriconazole

Question 25

ACANTHAMOEBA KERATITIS medication

Answer 25

- topical antiseptic polyhemamethyline biguanide 0.02% chlorhexidine 0.02% - pain medication - penetrating keratoplasy (in severe cases)

Question 26

SKIN LESION medication

Answer 26

- IV pentamidine - topical chlorhexidine - 2% ketaconazole - oral itraconazol

Question 27

Is there a person-to-person transmission in acanthamoebiasis?

Answer 27

No. Infection results from direct environmental exposure.

Question 28

dogs affected by this disease may exhibit persistent signs of cranial discomfort, including frequent whining or head pressing.

Answer 28

acanthamoebiasis (Granulomatous Amoebic Encephalitis (GAE))

Question 29

As the disease progresses, neurological symptoms become more evident, with dogs showing behavioral changes, disorientation, loss of coordination (ataxia), seizures, and circling movements. In severe cases, dogs may enter a stuporous or comatose state, and the disease often ends fatally if not treated promptly.

Answer 29

acanthamoebiasis (Granulomatous Amoebic Encephalitis (GAE))

Question 30

Primarily affects the eyes of healthy dogs, particularly those exposed to contaminated water sources or who have suffered corneal trauma.

Answer 30

acanthamoebiasis (Acanthamoeba Keratitis)

Question 31

Acanthamoeba Keratitis typically involves the formation of?

Answer 31

ring-shaped (annular or paracentric) infiltrate in the cornea

Question 32

Clinically, dogs may display signs of intense ocular discomfort, such as frequently pawing at the eye, squinting, or avoiding bright light (photophobia). Other signs include lacrimation, redness of the eye, visible corneal cloudiness, and pain. Without treatment, corneal ulcers may form, significantly impairing the dog's vision.

Answer 32

acanthamoebiasis (Acanthamoeba Keratitis)

Question 33

Infected dogs may develop localized areas of granulomatous inflammation, appearing as firm, raised nodules on the skin. Over time, these nodules may ulcerate, resulting in open, non-healing sores. In cases where the infection becomes systemic, these skin lesions may be accompanied by more severe, widespread signs of illness

Answer 33

acanthamoebiasis (Skin lesions)

Question 34

is a rare and serious condition, especially affecting immunocompromised dogs. The infection typically begins at a local site, such as broken skin or mucous membranes, but can spread to multiple organs, including the brain, lungs, liver, skin, and reproductive organs.

Answer 34

Disseminated acanthamoebiasis

Question 35

Disseminated acanthamoebiasis can spread to multiple organs, including the ff:

Answer 35

brain, lungs, liver, skin, and reproductive organs

Question 36

In severe cases, the infection can cause multisystem failure, leading to death. Diagnosis is often difficult and typically requires tissue biopsy to detect Acanthamoeba trophozoites and cysts. In some cases, the infection is confirmed post-mortem.

Answer 36

Disseminated acanthamoebiasis

Question 37

is commonly used to detect both trophozoites and cysts in tissue biopsy specimens such as those from the brain, skin, cornea, or cerebrospinal fluid in cases of acanthamoebiasis

Answer 37

Microscopy

Question 38

can also be used in treating Acanthamoeba infections due to its antiprotozoal effects.

Answer 38

Metronidazole

Question 39

MOA of Metronidazole in treating Acanthamoeba infections

Answer 39

disrupting DNA synthesis in the parasite

Question 40

In cases of acanthamoebiasis, once absorbed by the organism, Metronidazole is reduced to its active form, which forms __________ that damage the DNA, preventing replication and leading to cell death

Answer 40

toxic free radicals

Question 41

In cases of acanthamoebiasis, once absorbed by the organism, Metronidazole is reduced to its active form, which forms toxic free radicalsthat damage the DNA, preventing ________ and leading to cell death

Answer 41

replication

Question 42

Severe cases of Acanthamoeba keratitis may require surgical intervention, such as?

Answer 42

penetrating keratoplasty (corneal transplant)