Parasitology Research

, Volume 106, Issue 6, pp 1371–1377 | Cite as

Investigations of an extraordinary endocytobiont in Acanthamoeba sp.: development and replication

  • Patrick ScheidEmail author
  • Bärbel Hauröder
  • Rolf Michel
Original Paper


In this article, the results of investigations concerning a parasitic endocytobiont within the host amoebae (Acanthamoeba sp.) are presented. The endocytobiont was recently isolated from the contact lens and the inflamed eye of a patient with keratitis. Light microscopy and electron microscopy were performed to provide morphological details: Light microscopy revealed the presence of ovoid microorganisms developing and proliferating within the cytoplasm of the amoebic trophozoites. Details of the unusual development of these endocytobionts within the amoebae could be studied and demonstrated by means of electron microscopy. Foldings and morphological reorganization of the microorganisms took place exclusively within the host cytoplasm. The intracellularly aggregating organisms led to the rupture of the Acanthamoeba trophozoites after proliferation. Numerous microorganisms were released, which were infectious and were subsequently ingested by hitherto uninfected acanthamoebic trophozoites. To evaluate the in vitro growth of the isolated endocytobionts (without their hosts), they were transferred to several different culture plates. There was no growth of these unique organisms on five different common cultural plates suitable for the growth of bacteria and fungi.


Keratitis Food Vacuole Francisella Tularensis Haemine Intracellular Organism 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



We like to thank Dr. Dave Lam for his support and Elke Schneider for her help and assistance in obtaining these impressive electron micrographs.


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Patrick Scheid
    • 1
    Email author
  • Bärbel Hauröder
    • 2
  • Rolf Michel
    • 1
  1. 1.Laboratory of Medical ParasitologyCentral Institute of the Bundeswehr Medical Service KoblenzKoblenzGermany
  2. 2.Laboratory of Electron MicroscopyCentral Institute of the Bundeswehr Medical ServiceKoblenzGermany

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