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ACANTHAMOEBA
  FREE LIVING AMOEBA
FREE-LIVING AMOEBA
Amphizoic amoebae
      - They have also been
called amphizoic amoebae
because these amoebae
have the ability to exist as
free-living organisms in
nature and only occasionally
invade a host and live as
parasites within host tissue.
ACANTHAMOEBA
A microscopic, free-living amoeba that can cause rare,
 but severe infections of the eye, skin, and central
 nervous system.
Several species of Acanthamoeba, including A.
 culbertsoni, A. polyphaga, A. castellanii, A. astronyxis,
 A. hatchetti, A. rhysodes, A. divionensis, A. lugdunensis,
 and A. lenticulata are implicated in human disease.
 The important species is A.culbertsoni
ACANTHAMOEBA
Acanthamoeba spp. have been found in:
 • soil                       • heating, ventilating, and
 • fresh, brackish, and sea     air conditioning systems
   water                      • mammalian cell cultures
 • Sewage                     • Vegetables
 • swimming pools             • human nostrils and
 • contact lens equipment;      throats
 • medicinal pools            • human and animal brain,
 • dental treatment units       skin, and lung tissues.
 • dialysis machines
ACANTHAMOEBA
Has two stages, cysts and trophozoites, in its life
 cycle. No flagellated stage exists as part of the life
 cycle.
The trophozoites replicate by mitosis.
 When Acanthamoeba spp. enters the eye it can
 cause severe keratitis in otherwise healthy
 individuals, particularly contact lens users .
 When it enters the respiratory system or through
 the skin, it can invade the central nervous system
 by     hematogenous dissemination causing
 granulomatous amebic encephalitis (GAE) or
 disseminated disease, or skin lesions in
 individuals with compromised immune systems
ACANTHAMOEBA
LIFE CYCLE STAGES




  Free-living trophozoites and cysts occur in both
  the soil and freshwater.
ACANTHAMOEBA
Life cycle:
ACANTHAMOEBA
There are two morphological forms:
  Trophozoite
      - A trophozoite is 20-50µm in size
      - Rough exterior with several spine like
      projections(acanthopoda).
  Cyst
      - Spherical and 15µm in diameter.


 Both forms can be the source of infection
ACANTHAMOEBA




Trophozoite                     Cyst
 Feeding & dividing    Response to adversity
 Asexual               Dormant, resistant
 Cyst forming          Double-walled with pores
ACANTHAMOEBA
Pathogenicity and Clinical Features:
  Granulomatous Amebic Encephalitis (GAE) and
   disseminated infection primarily affect people with
   compromised immune systems.
  Commonly seen in immunocompromised patients,
   including those with neoplasia, systemic lupus
   erythematosus, human immunodeficiency virus
   and tuberculosis
 Incubation period:
  Unknown but estimated at weeks to months. The
   route of infection is aerosol or direct inoculation
   with hematogenous spread to the CNS.
ACANTHAMOEBA
Risk Factors:              Symptoms:
•   Alcoholism                   •   Headache
•   Drug abuse                   •   Confusion
•   Chemotherapy                 •   fever,
•   Corticosteroids              •   Lethargy
•   Organ transplantation        •   Nausea and vomiting
                                 •   Seizures
Signs:                          •   Photophobia
• Neck stiffness                 •   Neck stiffness.
• Focal neurological deficits    •   Patients may become
• Patients may also develop          frankly psychotic.
  raised intracranial pressure
Acanthamoeba Keratitis
   A progressive disease of the cornea, which
    is sight-threatening
 Commonly seen in:
    - immunocompetent patients.
      - However, infection does not
      confer immunity and reinfection   is
      common.
 Risk factors:
• poor contact lens hygiene
• corneal abrasion
• exposure of the eye to contaminated water
Acanthamoeba Keratitis
 Affected individual       Signs:
  may complain of:         • Conjunctival hyperemia
•   Eye pain               • Episcleritis
•   Eye redness            • Scleritis
•   Blurred vision         • Loosening of the corneal
•   Sensitivity to light     epithelium.
    (photophobia)          • Rarely, trophozoites can
•   Sensation of something
                             infiltrate the corneal
    in the eye
                             nerve and retina, leading
•   Excessive tearing
                             to chorioretinitis
Acanthamoeba Keratitis
Diagnosis
 CSF wet mount
    -usually lymphocyte
    predominance and low
    glucose (motile trophozoites)
 Culture-Agar plates seeded with
  E.coli
 Immunofluorescence           or
  polymerase chain reaction (PCR)
 Corneal scrape or biopsy
Acanthamoeba Keratitis
Prevention and Control
These guidelines should be followed by all contact lens users to help
reduce the risk of eye infections:
 Visit your eye care provider for regular eye
  examinations.
 Wear and replace contact lenses according to the
  schedule prescribed by your eye care provider.
 Remove contact lenses before any activity involving
  contact with water, including showering, using a hot
  tub, or swimming.
 Wash hands with soap and water and dry before
  handling contact lenses.
Acanthamoeba Keratitis
Prevention and Control
 Clean contact lenses according to instructions from your
  eye care provider and the manufacturer's guidelines.
  1. Never reuse or top off old solution. Use fresh cleaning or
     disinfecting solution each time lenses are cleaned and stored.
  2. Never use saline solution or rewetting drops to disinfect lenses.
     Neither solution is an effective or approved disinfectant.
  3. Be sure to clean, rub, and rinse your lenses each time you
     remove your lenses. Rubbing and rinsing your contact lenses will
     aid in removing harmful microbes and residues.
Acanthamoeba Keratitis
Prevention and Control
 Store reusable lenses in the proper storage case.
   1. Storage cases should be rubbed and rinsed with sterile contact
      lens solution (never use tap water), emptied, and left open to
      dry after each use.
   2. Replace storage cases at least once every three months.

 Contact lens users with questions regarding which
  solutions are best for them should consult their eye care
  providers. They should also consult their eye care
  providers if they have any of the following symptoms: eye
  pain or redness, blurred vision, sensitivity to light,
  sensation of something in the eye, or excessive tearing.
Granulomatous Amebic Encephalitis

    A serious
     infection of the
     brain and spinal
     cord that typically
     occurs in persons
     with a
     compromised
     immune system.
Granulomatous Amebic Encephalitis

Symptoms include:
•   Mental status changes         body
•   Loss of coordination      •   Double vision
•   Fever                     •   Sensitivity to light
•   Muscular weakness or •        Other neurologic
    partial paralysis             problems
    affecting one side of the
ACANTHAMOEBA
Treatment:
 Granulomatous Amebic Encephalitis (GAE) is treated
  with pentamidine, usually in combination with one or
  more of the following:
  •   Ketoconazole
  •   Hydroxystilbamidine
  •   Paromomycin
  •   5-fluorocytosine polymyxin
  •   Sulfadiazine
  •   Trimethoprim-sulfamethoxazole
  •   Azithromycin
ACANTHAMOEBA
Treatment:
 Acanthamoeba keratitis
    - Therapy should include the cationic antiseptic
    agents,    of      which   chlorhexidine     or
    polyhexamethylene biguanide (PHMB) is the most
    effective.

 Ocular lesions
    - Enucleation of ulcer and corneal transplant
REFERENCES
•   Contact Lens News and Information. (2012, February 20). Contact Lens Solutions Ineffective
        Against Acanthamoeba, Study Finds. Retrieved August 10, 2012, from
        http://t3.gstatic.com/images?q=tbn:ANd9GcTB4chV7tr0UeG44UKnU9qSBv4IOy_0_vA
        JrnYHIvhM75iGwMF

•   Centers for Disease Control and Prevention (CDC). Acanthamoeba - Granulomatous Amebic
        Encephalitis     (GAE);    Keratitis.   Retrieved    August   11,    2012,   from
        http://www.cdc.gov/parasites/acanthamoeba/disease.html

•   Centers for Disease Control and Prevention (CDC). Laboratory Identification of Parasites of
        Public Health Concern; Free-Living Amebic Infections. Retrieved August 11, 2012, from
        http://www.dpd.cdc.gov/dpdx/HTML/FreeLivingAmebic.htm

•   Simon Kilvington, PhD. (2008). Physiological Response of         Acanthamoeba to
        Contact Lens Disinfectants [Powerpoint Format]. Retrieved August 11, 2012, from
        http://www.google.com.ph/url?sa=t&rct=j&q=physiological%20response%20of%20ac

•   Animal Planet. Monsters inside me. Acanthamoeba picture. Retrieved August 15, 2012,
        from http://animal.discovery.com/invertebrates/monsters-inside-me/acanthamoeba-
        keratitis/
REFERENCES
•   The University of Edinburgh. (2003, May 28). Acanthamoeba. Retrieved August 15, 2012,
        from http://www.bms.ed.ac.uk/research/others/smaciver/Comp1.jpg

•   Baylor College of Medicine. (2008, January, 30). Human Genome Sequencing Center; About
         Acanthamoeba       castellani   Neff.    Retrieved  August   15,    2012,    from
         http://www.hgsc.bcm.tmc.edu/microbial-detail.xsp?project_id=163

•   Naveed, Khan. (2009). Acanthamoeba Biology and Pathogenesis. Retrieved August 15,
        2012, from http://www.caister.com/supplementary/acanthamoeba/c10.html
THANK YOU!
• Edna Mae C. Genzola, RMT
• Katherine Royce L. Panizales, RMT
• Mary Jean D. Somcio, RMT

More Related Content

Acanthamoeba

  • 1. ACANTHAMOEBA FREE LIVING AMOEBA
  • 2. FREE-LIVING AMOEBA Amphizoic amoebae - They have also been called amphizoic amoebae because these amoebae have the ability to exist as free-living organisms in nature and only occasionally invade a host and live as parasites within host tissue.
  • 3. ACANTHAMOEBA A microscopic, free-living amoeba that can cause rare, but severe infections of the eye, skin, and central nervous system. Several species of Acanthamoeba, including A. culbertsoni, A. polyphaga, A. castellanii, A. astronyxis, A. hatchetti, A. rhysodes, A. divionensis, A. lugdunensis, and A. lenticulata are implicated in human disease.  The important species is A.culbertsoni
  • 4. ACANTHAMOEBA Acanthamoeba spp. have been found in: • soil • heating, ventilating, and • fresh, brackish, and sea air conditioning systems water • mammalian cell cultures • Sewage • Vegetables • swimming pools • human nostrils and • contact lens equipment; throats • medicinal pools • human and animal brain, • dental treatment units skin, and lung tissues. • dialysis machines
  • 5. ACANTHAMOEBA Has two stages, cysts and trophozoites, in its life cycle. No flagellated stage exists as part of the life cycle. The trophozoites replicate by mitosis.  When Acanthamoeba spp. enters the eye it can cause severe keratitis in otherwise healthy individuals, particularly contact lens users .  When it enters the respiratory system or through the skin, it can invade the central nervous system by hematogenous dissemination causing granulomatous amebic encephalitis (GAE) or disseminated disease, or skin lesions in individuals with compromised immune systems
  • 6. ACANTHAMOEBA LIFE CYCLE STAGES Free-living trophozoites and cysts occur in both the soil and freshwater.
  • 8. ACANTHAMOEBA There are two morphological forms:  Trophozoite - A trophozoite is 20-50µm in size - Rough exterior with several spine like projections(acanthopoda).  Cyst - Spherical and 15µm in diameter. Both forms can be the source of infection
  • 9. ACANTHAMOEBA Trophozoite Cyst  Feeding & dividing  Response to adversity  Asexual  Dormant, resistant  Cyst forming  Double-walled with pores
  • 10. ACANTHAMOEBA Pathogenicity and Clinical Features:  Granulomatous Amebic Encephalitis (GAE) and disseminated infection primarily affect people with compromised immune systems.  Commonly seen in immunocompromised patients, including those with neoplasia, systemic lupus erythematosus, human immunodeficiency virus and tuberculosis Incubation period:  Unknown but estimated at weeks to months. The route of infection is aerosol or direct inoculation with hematogenous spread to the CNS.
  • 11. ACANTHAMOEBA Risk Factors: Symptoms: • Alcoholism • Headache • Drug abuse • Confusion • Chemotherapy • fever, • Corticosteroids • Lethargy • Organ transplantation • Nausea and vomiting • Seizures Signs: • Photophobia • Neck stiffness • Neck stiffness. • Focal neurological deficits • Patients may become • Patients may also develop frankly psychotic. raised intracranial pressure
  • 12. Acanthamoeba Keratitis  A progressive disease of the cornea, which is sight-threatening  Commonly seen in: - immunocompetent patients. - However, infection does not confer immunity and reinfection is common.  Risk factors: • poor contact lens hygiene • corneal abrasion • exposure of the eye to contaminated water
  • 13. Acanthamoeba Keratitis  Affected individual  Signs: may complain of: • Conjunctival hyperemia • Eye pain • Episcleritis • Eye redness • Scleritis • Blurred vision • Loosening of the corneal • Sensitivity to light epithelium. (photophobia) • Rarely, trophozoites can • Sensation of something infiltrate the corneal in the eye nerve and retina, leading • Excessive tearing to chorioretinitis
  • 14. Acanthamoeba Keratitis Diagnosis  CSF wet mount -usually lymphocyte predominance and low glucose (motile trophozoites)  Culture-Agar plates seeded with E.coli  Immunofluorescence or polymerase chain reaction (PCR)  Corneal scrape or biopsy
  • 15. Acanthamoeba Keratitis Prevention and Control These guidelines should be followed by all contact lens users to help reduce the risk of eye infections:  Visit your eye care provider for regular eye examinations.  Wear and replace contact lenses according to the schedule prescribed by your eye care provider.  Remove contact lenses before any activity involving contact with water, including showering, using a hot tub, or swimming.  Wash hands with soap and water and dry before handling contact lenses.
  • 16. Acanthamoeba Keratitis Prevention and Control  Clean contact lenses according to instructions from your eye care provider and the manufacturer's guidelines. 1. Never reuse or top off old solution. Use fresh cleaning or disinfecting solution each time lenses are cleaned and stored. 2. Never use saline solution or rewetting drops to disinfect lenses. Neither solution is an effective or approved disinfectant. 3. Be sure to clean, rub, and rinse your lenses each time you remove your lenses. Rubbing and rinsing your contact lenses will aid in removing harmful microbes and residues.
  • 17. Acanthamoeba Keratitis Prevention and Control  Store reusable lenses in the proper storage case. 1. Storage cases should be rubbed and rinsed with sterile contact lens solution (never use tap water), emptied, and left open to dry after each use. 2. Replace storage cases at least once every three months.  Contact lens users with questions regarding which solutions are best for them should consult their eye care providers. They should also consult their eye care providers if they have any of the following symptoms: eye pain or redness, blurred vision, sensitivity to light, sensation of something in the eye, or excessive tearing.
  • 18. Granulomatous Amebic Encephalitis  A serious infection of the brain and spinal cord that typically occurs in persons with a compromised immune system.
  • 19. Granulomatous Amebic Encephalitis Symptoms include: • Mental status changes body • Loss of coordination • Double vision • Fever • Sensitivity to light • Muscular weakness or • Other neurologic partial paralysis problems affecting one side of the
  • 20. ACANTHAMOEBA Treatment:  Granulomatous Amebic Encephalitis (GAE) is treated with pentamidine, usually in combination with one or more of the following: • Ketoconazole • Hydroxystilbamidine • Paromomycin • 5-fluorocytosine polymyxin • Sulfadiazine • Trimethoprim-sulfamethoxazole • Azithromycin
  • 21. ACANTHAMOEBA Treatment:  Acanthamoeba keratitis - Therapy should include the cationic antiseptic agents, of which chlorhexidine or polyhexamethylene biguanide (PHMB) is the most effective.  Ocular lesions - Enucleation of ulcer and corneal transplant
  • 22. REFERENCES • Contact Lens News and Information. (2012, February 20). Contact Lens Solutions Ineffective Against Acanthamoeba, Study Finds. Retrieved August 10, 2012, from http://t3.gstatic.com/images?q=tbn:ANd9GcTB4chV7tr0UeG44UKnU9qSBv4IOy_0_vA JrnYHIvhM75iGwMF • Centers for Disease Control and Prevention (CDC). Acanthamoeba - Granulomatous Amebic Encephalitis (GAE); Keratitis. Retrieved August 11, 2012, from http://www.cdc.gov/parasites/acanthamoeba/disease.html • Centers for Disease Control and Prevention (CDC). Laboratory Identification of Parasites of Public Health Concern; Free-Living Amebic Infections. Retrieved August 11, 2012, from http://www.dpd.cdc.gov/dpdx/HTML/FreeLivingAmebic.htm • Simon Kilvington, PhD. (2008). Physiological Response of Acanthamoeba to Contact Lens Disinfectants [Powerpoint Format]. Retrieved August 11, 2012, from http://www.google.com.ph/url?sa=t&rct=j&q=physiological%20response%20of%20ac • Animal Planet. Monsters inside me. Acanthamoeba picture. Retrieved August 15, 2012, from http://animal.discovery.com/invertebrates/monsters-inside-me/acanthamoeba- keratitis/
  • 23. REFERENCES • The University of Edinburgh. (2003, May 28). Acanthamoeba. Retrieved August 15, 2012, from http://www.bms.ed.ac.uk/research/others/smaciver/Comp1.jpg • Baylor College of Medicine. (2008, January, 30). Human Genome Sequencing Center; About Acanthamoeba castellani Neff. Retrieved August 15, 2012, from http://www.hgsc.bcm.tmc.edu/microbial-detail.xsp?project_id=163 • Naveed, Khan. (2009). Acanthamoeba Biology and Pathogenesis. Retrieved August 15, 2012, from http://www.caister.com/supplementary/acanthamoeba/c10.html
  • 24. THANK YOU! • Edna Mae C. Genzola, RMT • Katherine Royce L. Panizales, RMT • Mary Jean D. Somcio, RMT