Journal of Parasitic Diseases

, Volume 40, Issue 2, pp 369–373 | Cite as

Viability and morphological changes of Acanthamoeba spp. cysts after treatment with Effective microorganisms (EM)

  • Tanitta Sampaotong
  • Usa Lek-Uthai
  • Jantima Roongruangchai
  • Kosol Roongruangchai
Original Article


Acanthamoeba is a free-living opportunistic protozoan parasite that is found in diverse environments. It can cause keratitis, mostly related to inappropriate use of contact lenses, as well as life threatening diseases including encephalitis, disseminated sinusitis, and skin ulcers. This study investigated morphological changes and fine structures of the cyst form of Acanthamoeba spp. after treatment with effective microorganisms (EM™) using light and scanning electron microscopies. Acanthamoeba cysts treated with 1:2, 1:4, 1:6, and undiluted EM™ showed higher percentages of non-viable cysts than those treated with 1:8, 1:10, 1:100, 1:200, and 1:400 EM™ and at 5 days post-treatment developed from cystic stage to trophozoite stage. Acanthamoeba cysts treated at concentrations of 1:2, 1:4, 1:6, and undiluted EM™ exhibited cytoplasmic clumping and shrinkage of amoeba cells away from cyst walls. The effective EM™ concentration lethal to Acanthamoeba spp. cyst could provide information to monitor the environmental control system.


Acanthamoeba spp. Effective microorganisms Viability and morphological changes 



We gratefully acknowledge the help and support provided by the staff of the Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University. This work was partially supported for publication by the China Medical Board, Faculty of Public Health, Mahidol University, Bangkok, Thailand (Usa Lek-Uthai).


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Copyright information

© Indian Society for Parasitology 2014

Authors and Affiliations

  • Tanitta Sampaotong
    • 1
    • 2
  • Usa Lek-Uthai
    • 2
  • Jantima Roongruangchai
    • 3
  • Kosol Roongruangchai
    • 4
  1. 1.Faculty of Graduate StudiesMahidol UniversityBangkokThailand
  2. 2.Department of Parasitology and Entomology, Faculty of Public HealthMahidol UniversityBangkokThailand
  3. 3.Department of Anatomy, Faculty of Medicine, Siriraj HospitalMahidol UniversityBangkokThailand
  4. 4.Department of Parasitology, Faculty of Medicine, Siriraj HospitalMahidol UniversityBangkokThailand

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