Abstract
Purpose:
To evaluate diagnostic advantage of including liquid media along with solid media in the laboratory diagnosis of infective endophthalmitis.
Methods:
Nine hundred and fourteen cases of clinically diagnosed infective endophthalmitis cases comprising of endogenous, post-operative and post-traumatic endophthalmitis were investigated over a period of 2 years, 5 months. Anterior chamber fluid and/or vitreous fluid from all cases were submitted to the microbiology laboratory and processed aseptically within one hour. Samples that were collected beyond laboratory working hours were inoculated on all media in the operating room and submitted to the laboratory on the following day. All samples were examined by direct microscopy (10% potassium hydroxide with 0.1% calcofluor white mount, Gram stain and Giemsa stain) and were subjected to culture (5% sheep blood agar, chocolate agar, Sabouraud dextrose agar, potato dextrose agar, brain heart infusion and thioglycollate broth). Cases whose samples were cultured in both liquid and solid media were included in the study. The results of microscopy and culture results in both liquid and solid media were analyzed for their impact on management of the patients. Further a detailed retrospective analysis was done of cases that showed positive results either in liquid media alone or a growth in liquid media prior to other media.
Results:
Out of the 914 intraocular samples included in the study, 227 (24.83%) were culture positive with significant growth, while 687 (75.16%) were culture negative. The culture positive cases comprised of 198 (87.22%) bacterial, 20 (8.81%) fungal and 8 (3.52%) polymicrobial infections. Coagulase negative Staphylococcus was isolated in 49/227 cases (21.58%), being the most common organism. Positive culture results were established in 23 (10.13%) patients on the basis of growth in liquid media alone. Among them, 15 showed growth exclusively in liquid media while 8 showed growth in liquid media prior to that on solid media. In 7 of 23 patients, the treatment was modified by the clinician based on the antibiotic susceptibility report and microorganism grown in liquid media.
Conclusions:
Inclusion of liquid culture media along with solid media for the culture of intraocular fluids increases the probability of early diagnosis of endophthalmitis and in turn early institution of targeted therapy.
Keywords: 513 endophthalmitis •
763 vitreous