16S Ribosomal RNA PCR Versus Conventional Diagnostic Culture in the Investigation of Suspected Bacterial Keratitis

PurposeThe purpose of this study was to compare conventional diagnostic culture (CDC) to 16S ribosomal RNA polymerase chain reaction (PCR) analysis for diagnosing bacterial keratitis.MethodsSamples collected from 100 consecutive patients presenting to the Royal Liverpool University Hospital with bacterial keratitis were processed using CDC and 16S PCR analysis.ResultsThe overall detection rate using both methods was 36%. Of these, 72.2% (26/36) were detected by PCR and 63.9% (23/36) isolated by CDC (P = 0.62). Using a combination of both PCR and CDC increased the detection rate for pathogenic bacteria by 13% compared to using CDC alone (P = 0.04). In CDC negative samples, 16S PCR identified more pathogens than CDC in 16S PCR negative samples. Neither order of sample collection nor prior antimicrobial use affected the detection rate.Conclusions16S rRNA gene PCR performed in addition to CDC on corneal samples from patients with clinically suspected bacterial keratitis led to additional pathogen detection.Translational relevance16S rRNA gene PCR should be developed to become an additional part of clinical service for patients with bacterial keratitis rather than used in isolation