This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this link to a friend Similar articles in this journal Similar articles in PubMed Add article to my folders Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gaudio, P A Articles by Hughes, T E Search for Related Content PubMed PubMed Citation Articles by Gaudio, P A Articles by Hughes, T E

Polymerase chain reaction based detection of fungi in infected corneas

¹ Yale Eye Center, New Haven, CT, USA
² LV Prasad Eye Institute, Hyderabad, India

Correspondence to:
Correspondence to:
Thomas E Hughes, PhD, Yale Eye Center, 330 Cedar Street, New Haven, CT 06520, USA;
thomas.hughes{at}yale.edu

Aims: To evaluate a polymerase chain reaction (PCR) based assay to detect fungi in scrapings from infected corneas.

Methods: A PCR assay was developed to amplify a portion of the fungal 18S ribosome gene. Corneal scrapings from 30 patients with presumed infectious keratitis were evaluated using this assay, as well as by standard microbiological techniques, and the results were compared. Conjunctival swabs from each patient's healthy, fellow eye were also evaluated by PCR.

Results: PCR and fungal culture results matched (were both positive or both negative for fungi) in 22 (74%) of 30 scrapings from infected corneas. Three (10%) of 30 samples were PCR positive but fungal culture negative; two of these appeared clinically to represent fungal infections, and the third was clinically indeterminate. Four (13%) scrapings were positive by PCR but also by bacterial and not fungal culture. One specimen (3%) was PCR negative but fungal culture positive. Of the conjunctival swabs from each patient's healthy fellow eye, five (17%) of 30 were positive by PCR, and the opposite, infected eye of all five of these harboured a fungal infection.

Conclusions: PCR is promising as a means to diagnose fungal keratitis and offers some advantages over culture methods, including rapid analysis and the ability to analyse specimens far from where they are collected.

Keywords: molecular diagnostics; India; keratomycosis; field studies

This article has been cited by other articles:

				S. Vengayil, A. Panda, G. Satpathy, N. Nayak, S. Ghose, D. Patanaik, and S. Khokhar Polymerase Chain Reaction-Guided Diagnosis of Mycotic Keratitis: A Prospective Evaluation of Its Efficacy and Limitations Invest. Ophthalmol. Vis. Sci., January 1, 2009; 50(1): 152 - 156. [Abstract] [Full Text] [PDF]

				M J Bharathi, R Ramakrishnan, R Meenakshi, S Mittal, C Shivakumar, and M Srinivasan Microbiological diagnosis of infective keratitis: comparative evaluation of direct microscopy and culture results Br. J. Ophthalmol., October 1, 2006; 90(10): 1271 - 1276. [Abstract] [Full Text] [PDF]

				P. A. Thomas Current Perspectives on Ophthalmic Mycoses Clin. Microbiol. Rev., October 1, 2003; 16(4): 730 - 797. [Abstract] [Full Text] [PDF]

				Molecular diagnosis may help management of ocular infection J. Clin. Pathol., September 1, 2002; 55(9): 720 - 720. [Full Text] [PDF]