Search

Aim: To measure the bacterial genome in ocular fluids and to analyse the clinical relevance of infectious endophthalmitis., Methods: Nineteen ocular fluid samples (eight aqueous humour and 11 vitreous fluid samples) were collected from 19 patients with suspected bacterial endophthalmitis. Fifty ocular samples from uveitis patients were also collected along with 40 samples from patients without ocular inflammation and used as controls. Bacterial ribosomal DNA (16S rDNA) was measured by a quantitative PCR assay., Results: Bacterial 16S rDNA was detected in patients with clinically suspected bacterial endophthalmitis (18/19, 95%). With the exception of one case, high copy numbers of bacterial DNA were detected (1.7×10(3)-1.7×10(9) copies/ml) in these patients. There were 10 samples (53%) with positive bacterial cultures while there were nine samples (47%) with positive Gram-staining. Real-time PCR detected bacterial 16S rDNA in three (6%) of the 50 samples from the control uveitis patients. In addition, none of the samples from the control patients without intraocular inflammation were positive., Conclusions: Quantitative broad-range PCR of bacterial 16S rDNA is a useful tool for diagnosing bacterial endophthalmitis.

Purpose: To measure the genomic DNA from Epstein-Barr virus (EBV) in ocular fluids and to analyze the clinical relevance of EBV in uveitis., Methods: Intraocular fluids (30 aqueous humor and 30 vitreous fluid samples) were taken from 55 patients with uveitis after informed consent was obtained. Samples were assayed for EBV DNA using qualitative multiplex polymerase chain reaction (PCR) and quantitative real-time PCR. Antibodies to EBV were examined using a complement fixation test., Results: EBV DNA was detected in 17 of 60 samples (28%) and 16 of 55 patients (29%) using multiplex PCR. However, only three of the 17 samples showed significantly high copy numbers of EBV DNA with real-time PCR. EBV DNA was not detected in the serum of all patients. EBV-specific antibodies were positive in the serum of all patients, but not in the vitreous fluid. Vitreous anti-EBV antibodies were positive only in patients displaying genomic DNA of EBV in the vitreous samples., Conclusions: EBV DNA was detected by qualitative PCR in ocular fluids of many uveitis patients, but only a small proportion of patients showed high viral loads on quantitative real-time PCR, indicating that replication of the virus takes place only in a few patients.

Aim: To measure the genomic DNA of human herpes viruses (HHV) in the ocular fluids and to analyse the clinical relevance of HHV in uveitis., Methods: After informed consent was obtained, a total of 111 ocular fluid samples (68 aqueous humour and 43 vitreous fluid samples) were collected from 100 patients with uveitis. The samples were assayed for HHV-DNA (HHV1-8) by using two different polymerase chain reaction (PCR) assays, qualitative PCR (multiplex PCR) and quantitative PCR (real-time PCR)., Results: In all of the patients with acute retinal necrosis (n = 16) that were tested, either the HSV1 (n = 2), HSV2 (n = 3), or VZV (n = 11) genome was detected. In all patients, high copy numbers of the viral DNA were also noted, indicating the presence of viral replication. In another 10 patients with anterior uveitis with iris atrophy, the VZV genome was detected. When using multiplex PCR, EBV-DNA was detected in 19 of 111 samples (17%). However, real-time PCR analysis of EBV-DNA indicated that there were only six of the 19 samples that had significantly high copy numbers. The cytomegalovirus (CMV) genome was detected in three patients with anterior uveitis of immunocompetent patients and in one immunocompromised CMV retinitis patient. In addition, one patient with severe unilateral panuveitis had a high copy number of HHV6-DNA. There was no HHV7- or HHV8-DNA detected in any of the samples., Conclusions: A qualitative multiplex PCR is useful in the screening of viral infections. However, the clinical relevance of the virus infection needs to be evaluated by quantitative real-time PCR.