Skip to main content
Article thumbnail
Location of Repository

Isolation of Acanthamoeba isolates belonging to T2, T3, T4 and T7 genotypes from environmental samples in Ankara, Turkey

By A. Kiliç, M. Tanyuksel, J. Sissons, S. Jayasekera and Naveed Ahmed Khan


Acanthamoeba keratitis is a blinding infection that is becoming increasingly important in human health. Early diagnosis is a prerequisite for successful treatment and requires identification of Acanthamoeba at the genotypic level. The genus Acanthamoeba consists of both pathogenic and non-pathogenic species and has been recently classified into 13 different genotypes, T1-T12 and T14. More importantly, 95% of Acanthamoeba isolates that produce keratitis belong to T4 genotypes. In this study, we attempted to determine whether predominance of T4 isolates in Acanthamoeba keratitis is due to greater virulence or greater prevalence. We isolated 18 Acanthamoeba isolates from environmental samples in Ankara, Turkey and determined their pathogenic potential by means osmotolerance, temperature tolerance and in vitro cytotoxicity assays using corneal epithelial cells. Ribosomal DNA sequencing revealed that 10 isolates belong to T2, 5 belong to T3, 2 belong to T4 and one belongs to T7 genotype. As expected, T3 and T4 isolates exhibited the most pathogenic traits and were osmotolerant, temperature tolerant and exhibited severe corneal epithelial cell cytotoxicity indicating their pathogenic potential. Overall these data indicate that high frequency of T4 isolates in keratitis cases may well be due to their greater virulence. This is the first report presenting environmental distribution of Acanthamoeba in Ankara, Turkey

Topics: bcs
Publisher: Springer
Year: 2004
OAI identifier:

Suggested articles


  1. (2002). 18S ribosomal DNA typing and tracking of Acanthamoeba species isolates from corneal scrape specimens, contact lenses, lens cases, and home water supplies of Acanthamoeba keratitis patients in Hong Kong. doi
  2. (2001). Acanthamoeba can be differentiated clinically by the polymerase chain reaction and simple plating assays. doi
  3. (2003). Acanthamoeba interactions with human brain microvascular endothelial cells. doi
  4. (2003). Acanthamoeba spp. as agents of disease in humans. doi
  5. (1994). Acanthamoeba: biology, ecology and human disease. doi
  6. (1996). Amebic keratitis in a wearer of disposable contact lenses due to a mixed Vahlkampfia and Hartmannella infection. doi
  7. (2001). Anti-Acanthamoeba IgG, IgM, and IgA immunoreactivities in correlation to strain pathogenicity. doi
  8. (2004). Correlations between morphological, molecular biological, and physiological characteristics in clinical and nonclinical isolates of Acanthamoeba spp. doi
  9. (2001). Development of an Acanthamoeba-specific reverse dot-blot and the discovery of a new ribotype. doi
  10. (2003). Epidemiological typing of Acanthamoeba strains isolated from keratitis cases in Belgium. Bulletin de la Société Belge d’Ophthalmologie,
  11. (2003). Genotypic, phenotypic, biochemical, physiological and pathogenicity-based categorisation of Acanthamoeba strains. doi
  12. (1983). Growth characteristics, cytopathic effect in cell culture and virulence in mice of 36 type strains belonging to 19 different Acanthamoeba spp.
  13. (2002). Molecular and physiological differentiation between pathogenic and non-pathogenic Acanthamoeba. doi
  14. (2002). Molecular tools for speciation and epidemiological studies of Acanthamoeba. doi
  15. (2003). Pathogenesis of Acanthamoeba infections. doi
  16. (2001). Pathogenicity, morphology and differentiation of Acanthamoeba. doi
  17. (1996). PCR and RFLP variation of conserved region of small subunit ribosomal DNA among Acanthamoeba isolates assigned to either A. castellanii or A. polyphaga. doi
  18. (1996). PCR and RFLP variation of conserved region of small subunit ribosomal DNA among Acanthamoebaisolates assigned to either A.castellanii or A.polyphaga. doi
  19. (1989). PHYLIP – phylogeny inference package, doi
  20. (1997). Prevalence of pathogenic Acanthamoeba (Protozoa: Amoebidae) in the atmosphere of the city of San Luis Potosi, doi
  21. (2000). Proteases as markers of differentiation of pathogenic and nonpathogenic Acanthamoeba. doi
  22. (2001). Standardized method of measuring Acanthamoeba antibodies in sera from healthy human subjects. doi
  23. (2000). Substance P-induced cadherin expression and its signal transduction in a cloned human corneal epithelial cell line. doi
  24. (1989). The epidemiology of Acanthamoeba keratitis in the United States.
  25. (1998). The evolutionary history of the genus Acanthamoeba and the identification of eight new 18S rRNA gene sequence types. doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.