|
|
||||||||
1From the Departments of Ophthalmology and 7Microbiology, University Hospital Center (CHU) de Grenoble, Université Joseph Fourier, Grenoble, France; the 2Department of Ophthalmology, Hôpital Edouard Herriot, and 4Centre National de Référence des Staphylocoques, Faculté Laennec, Université Lyon 1, Lyon, France; 3INSERM (Institut National de la Santé et de la Recherche Médicale), U851, Lyon, France; 5Laboratoire de Bactériologie, Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, Bron, France; the 6Departments of Ophthalmology and 10Microbiology, CHU de Saint-Etienne, Saint-Etienne University, Saint-Etienne, France; and the 8Departments of Ophthalmology and 9Microbiology, CHU de Dijon, Dijon University, Dijon, France.
PURPOSE. To evaluate eubacterial PCR compared with conventional cultures for detection and identification of bacterial agents in ocular samples from patients with acute postcataract endophthalmitis.
METHODS. Broad-range eubacterial PCR amplification was used, followed by direct DNA sequencing in ocular samples (aqueous humor, vitreous samples from tap or vitrectomy) from 100 consecutive patients presenting with acute postcataract endophthalmitis. Bacterial cultures were performed on the same ocular samples by using traditional methods (brain-heart infusion broth).
RESULTS. At the time of admission, the detection rate was not significantly different between cultures and PCR (38.2% for cultures versus 34.6% for PCR in aqueous humor samples; 54% versus 57% in vitreous from a vitreous tap). In contrast, in the vitreous obtained from vitrectomy, after intravitreous injection of antibiotics, PCR detected bacteria in 70% of the cases, compared with 9% in cultures. By combining PCR and cultures, bacterial identification was obtained in 47% of aqueous humor samples at admission, in 68% of vitreous samples from a vitreous tap at admission, and in 72% of vitreous samples from pars plana vitrectomy. Gram-positive bacteria predominated (94.3%). The concordance between cultures and PCR was 100%. The contamination rate was 2%.
CONCLUSIONS. Cultures and eubacterial PCR are complementary techniques for bacterial identification in eyes with acute postcataract endophthalmitis. PCR technique was needed for identification of the involved microbial pathogen in 25% of all the cases. Eubacterial PCR is more effective than cultures in detecting bacteria in vitreous samples from patients with previous intravitreous administration of antibiotics.
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |