1887

Abstract

keratitis (AK) is a corneal disease caused by members of a genus of free-living amoebae and is associated predominantly with contact lens (CL) use. This study reports 16 cases of culture-proven AK diagnosed in northern Italy. Genotype identification was carried out with a PCR assay based on sequence analysis of the 18S rRNA gene, and sensitivity and specificity were evaluated in comparison with traditional parasitological techniques. A 405 bp region of the 18S rRNA gene (ASA.S1) including diagnostic fragment 3 (DF3) was amplified using the genus-specific primers JDP1 and JDP2. Genotype assignment was based on phenetic analysis of the ASA.S1 subset of the nuclear small-subunit rRNA gene sequence excluding the highly variable DF3 region. Phylogenetic analysis was also performed on the sequences obtained. All patients complained of monolateral infection; 11 (68.75%) admitted improper CL disinfection. In 14/16 (87.5 %) subjects, corneal scrapings were stained with calcofluor white and haematoxylin and eosin and, in ten cases (62.5 %), microscopy was positive for cysts. culture on 3 % non-nutrient agar plates was obtained in all cases (100 %), whereas cloning and axenic growth were positive for 14 amoebic stocks (87.5 %). PCR analysis had 100 % sensitivity and specificity compared with axenic culture, showing positive amplification from 15 isolates. All strains belonged to the T4 genotype, the main AK-related genotype worldwide. These results confirmed the importance of a complete diagnostic protocol, including a PCR assay, for the clinical diagnosis of AK on biological samples. Genotyping allowed inclusion of all isolates in the T4 group, thus demonstrating the prevalence of this genotype in northern Italy.

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2010-11-01
2024-03-29
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References

  1. Alizadeh H., Neelam S., Hurt M., Niederkorn J. Y. 2005; Role of contact lens wear, bacterial flora, and mannose-induced pathogenic protease in the pathogenesis of amoebic keratitis. Infect Immun 73:1061–1068 [CrossRef]
    [Google Scholar]
  2. Booton G. C., Visvesvara G. S., Byers T. J., Kelley D. J., Fuerst P. A. 2005; Identification and distribution of Acanthamoeba species genotypes associated with nonkeratitis infections. J Clin Microbiol 43:1689–1693 [CrossRef]
    [Google Scholar]
  3. Cohen E. J. 2009; Contact lens solutions: part of the problem. Arch Ophthalmol 127:1544–1546 [CrossRef]
    [Google Scholar]
  4. Di Cave D., Monno R., Bottalico P., Guerriero S., D'Amelio S., D'Orazi C., Berrilli F. 2009; Acanthamoeba T4 and T15 genotypes associated with keratitis infections in Italy. Eur J Clin Microbiol Infect Dis 28:607–612 [CrossRef]
    [Google Scholar]
  5. Hammersmith K. M. 2006; Diagnosis and management of Acanthamoeba keratitis. Curr Opin Ophthalmol 17:327–331 [CrossRef]
    [Google Scholar]
  6. Johnston S. P., Sriram R., Qvarnstrom Y., Roy S., Verani J., Yoder Y., Lorick S., Roberts J., Beach M. J., Visvesvara G. 2009; Resistance of Acanthamoeba cysts to disinfection in multiple contact lens solutions. J Clin Microbiol 47:2040–2045 [CrossRef]
    [Google Scholar]
  7. Joslin C. E., Tu E. Y., Shoff M. E., Booton G. C., Fuerst P. A., McMahon T. T., Anderson R. J., Dworkin M. S., Sugar J. other authors 2007; The association of contact lens solution use and Acanthamoeba keratitis. Am J Ophthalmol 144:169–180 [CrossRef]
    [Google Scholar]
  8. Khan N. A. 2006; Acanthamoeba biology and increasing importance in human health. FEMS Microbiol Rev 30:564–595 [CrossRef]
    [Google Scholar]
  9. Khan N. A. 2009 Acanthamoeba. Biology and Pathogenesis Norwich, UK: Caister Academic Press;
    [Google Scholar]
  10. Ledee D. R., Iovieno A., Miller D., Mandal N., Diaz M., Fell J., Fini M. E., Alfonso E. C. 2009; Molecular identification of T4 and R5 genotypes in isolates from Acanthamoeba keratitis patients. J Clin Microbiol 47:1458–1462 [CrossRef]
    [Google Scholar]
  11. Lindsay R. G., Watters G., Johnson R., Ormonde S. E., Snibson G. R. 2007; Acanthamoeba keratitis and contact lens wear. Clin Exp Optom 90:351–360 [CrossRef]
    [Google Scholar]
  12. Maghsood A. H., Sissons J., Rezaian M., Nolder D., Warhurst D., Khan N. A. 2005; Acanthamoeba genotype T4 from the UK and Iran and isolation of the T2 genotype from clinical isolates. J Med Microbiol 54:755–759 [CrossRef]
    [Google Scholar]
  13. Marciano-Cabral F., Cabral G. 2003; Acanthamoeba spp. as agents of disease in humans. Clin Microbiol Rev 16:273–307 [CrossRef]
    [Google Scholar]
  14. McAllum P., Bahar I., Kaiserman I., Srinivasan S., Slomovic A., Rootman D. 2009; Temporal and seasonal trends in Acanthamoeba keratitis. Cornea 28:7–10 [CrossRef]
    [Google Scholar]
  15. Moura H., Wallace S., Visvesvara G. S. 1992; Acanthamoeba healyi n. sp. and the isoenzyme and immunoblot profiles of Acanthamoeba spp., groups 1 and 3. J Protozool 39:573–583 [CrossRef]
    [Google Scholar]
  16. Pussard M., Pons R. 1977; Morphologie de la paroi kystique et taxonomie du genre Acanthamoeba (Protozoa, Amoebida). Protistologica (Paris) 13:557–610 (in French)
    [Google Scholar]
  17. Qvarnstrom Y., Visvesvara G. S., Sriram R., da Silva A. 2006; Multiplex real-time PCR assay for simultaneous detection of Acanthamoeba spp., Balamuthia mandrillaris , and Naegleria fowleri . J Clin Microbiol 44:3589–3595 [CrossRef]
    [Google Scholar]
  18. Schroeder J. M., Booton G. C., Ha J., Niszl I. A., Seal D. V., Markus M. B., Fuerst P. A., Byers T. J. 2001; Use of subgenic 18S ribosomal DNA PCR and sequencing for genus and genotype identification of acanthamoebae from humans with keratitis and from sewage sludge. J Clin Microbiol 39:1903–1911 [CrossRef]
    [Google Scholar]
  19. Schuster F. L. 2002; Cultivation of pathogenic and opportunistic free-living amebas. Clin Microbiol Rev 15:342–354 [CrossRef]
    [Google Scholar]
  20. Schuster F. L., Visvesvara G. 2004; Free-living amoebae as opportunistic and non-opportunistic pathogens in humans and animals. Int J Parasitol 34:1001–1027 [CrossRef]
    [Google Scholar]
  21. Seal D. V. 2003; Acanthamoeba keratitis: update-incidence, molecular epidemiology and new drugs for treatment. Eye (Lond) 17:893–905 [CrossRef]
    [Google Scholar]
  22. Sharma S., Garg P., Rao G. N. 2000; Patient characteristics, diagnosis and treatment of non-contact lens related Acanthamoeba keratitis. Br J Ophthalmol 84:1103–1108 [CrossRef]
    [Google Scholar]
  23. Stapleton F., Ozkan J., Jalbert I., Holden B. A., Petsoglou C., McClellan K. 2009; Contact lens-related Acanthamoeba keratitis. Optom Vis Sci 86:E1196–E1201 [CrossRef]
    [Google Scholar]
  24. Stehr-Green J. K., Bailey T. M., Brandt F. H., Carr J. H., Bond W. W., Visvesvara G. S. 1987; Acanthamoeba keratitis in soft contact lens wearers. A case–control study. JAMA 258:57–60 [CrossRef]
    [Google Scholar]
  25. Verani J. R., Lorich S. A., Yoder J. S., Beach M. J., Braden C. R., Roberts J. M., Conover C. S., Chen S., McConnell K. A. other authors 2009; National outbreak of Acanthamoeba keratitis associated with the use of a contact lens solution, United States. Emerg Infect Dis 15:1236–1242 [CrossRef]
    [Google Scholar]
  26. Visvesvara G. S., Moura H., Schuster F. L. 2007; Pathogenic and opportunistic free-living amoebae: Acanthamoeba spp., Balamuthia mandrillaris , Naegleria fowleri , and Sappinia diploidea . FEMS Immunol Med Microbiol 50:1–26 [CrossRef]
    [Google Scholar]
  27. Yera H., Zamfir O., Bourcier T., Ancelle T., Batellier L., Dupouy-Camet J., Chaumeil C. 2007; Comparison of PCR, microscopic examination and culture for the early diagnosis and characterization of Acanthamoeba isolates from ocular infections. Eur J Clin Microbiol Infect Dis 26:221–224 [CrossRef]
    [Google Scholar]
  28. Zhao G., Sun S., Zhao J., Xie L. 2010; Genotyping of Acanthamoeba isolates and clinical characteristics of patients with Acanthamoeba keratitis in China. J Med Microbiol 59:462–466 [CrossRef]
    [Google Scholar]
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