Abstract
In the study presented here, PCR, microscopic examination and culture of corneal samples were compared as methods of confirming the clinical diagnosis of Acanthamoeba keratitis, a serious ocular infection that is difficult to diagnose and threatens eyesight. The three methods were applied to isolates obtained from 513 patients with clinical signs or risk factors suggesting Acanthamoeba infection. Acanthamoeba keratitis was diagnosed in 12 of these patients. Combined PCR assays were more sensitive (94%) than either microscopic examination (33%) or culture (7%). The Acanthamoeba isolates were characterized using DNA sequence analysis of the nuclear small-subunit rRNA gene, and T4 was the predominant genotype found.
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Stothard DR, Hay J, Schroeder-Diedrich JM, Seal DV, Byers TJ (1999) Fluorescent oligonucleotide probes for clinical and environmental detection of Acanthamoeba and the T4 18S rRNA gene sequence type. J Clin Microbiol 37:2687–2693
Mathers WD, Nelson SE, Lane JL, Wilson ME, Allen RC, Folberg R (2000) Confirmation of confocal microscopy diagnosis of Acanthamoeba keratitis using polymerase chain reaction analysis. Arch Ophthalmol 118:178–183
Lehmann OJ, Green SM, Morlet N, Kilvington S, Keys MF, Matheson MM, Dart JK, McGill JI, Watt PJ (1998) Polymerase chain reaction analysis of corneal epithelial and tear samples in the diagnosis of Acanthamoeba keratitis. Invest Ophthalmol Vis Sci 39:1261–1265
Pasricha G, Sharma S, Garg P, Aggarwal RK (2003) Use of 18S rRNA gene-based PCR assay for diagnosis of Acanthamoeba keratitis in non-contact lens wearers in India. J Clin Microbiol 41:3206–3211
Schroeder JM, Booton GC, Hay J, Niszl IA, Seal DV, Markus MB, Fuerst PA, Byers TJ (2001) Use of subgenic 18S ribosomal DNA PCR and sequencing for genus and genotype identification of Acanthamoeba from humans with keratitis and from sewage sludge. J Clin Microbiol 39:1903–1911
Booton GC, Kelly DJ, Chu YW, Seal DV, Houang E, Lam DS, Byers TJ, Fuerst PA (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. J Clin Microbiol 40:1621–1625
Stothard DR, Schroeder-Diedrich JM, Awwad MH, Gast RJ, Ledee DR, Rodriguez-Zaragoza S, Dean CL, Fuerst PA, Byers TJ (1998) The evolutionary history of the genus Acanthamoeba and the identification of eight new 18S rRNA gene sequence types. J Eukaryot Microbiol 45:45–54
Walochnik J, Obwaller A, Aspock H (2000) Correlations between morphological, molecular biological, and physiological characteristics in clinical and nonclinical isolates of Acanthamoeba spp. Appl Environ Microbiol 66:4408–4413
Booton GC, Visvesvara GS, Byers TJ, Kelly DJ, Fuerst PA (2005) Identification and distribution of Acanthamoeba species genotypes associated with nonkeratitis infections. J Clin Microbiol 43:1689–1693
Visvesvara GS (1991) Classification of Acanthamoeba. Rev Infect Dis 13(Suppl 5):369–372
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The experiments performed in this study comply with the current laws of France.
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Yera, H., Zamfir, O., Bourcier, T. et al. 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 (2007). https://doi.org/10.1007/s10096-007-0268-6
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DOI: https://doi.org/10.1007/s10096-007-0268-6