Evaluation of polymerase chain reaction for the detection of adenoviruses in conjunctival swab specimens using degenerate primers in comparison with direct immunofluorescence

Abstract

Purpose: To investigate a rapid and sensitive polymerase chain reaction (PCR)-based assay for the detection of adenoviral infections in conjunctival swabs.

Methods: Degenerate primers derived from the adenoviral hexon gene were designed for amplification of a 302-bp product by PCR. In 15 ocular swab specimens, using a simple sample preparation method, PCR was compared with a commercially available direct immunofluorescence test.

Results: Fourteen samples of patients with clinically diagnosed adenoviral keratoconjunctivitis, when screened by direct immunofluorescence, were positive for adenoviral protein. In all samples positive by immunofluorescence, the 302-bp product was amplifiable. The sample negative by direct immunofluorescence was positive using PCR.

Conclusion: PCR using degenerate primers proved to have several advantages over current diagnostic techniques. It offers considerable improvement in sensitivity over immunoassays and speed over tissue culture isolation and is a highly potential tool for the diagnosis of adenoviral ocular infections.