The role of a panfungal PCR in the etiological diagnosis of endophthalmitis in a tertiary care ophthalmology hospital in Eastern India

Anjan Mukherjee*, Soumen Pramanik, Sudipta Das, Rupak Ray, Krishnendu Nandi, S.S.Paul

Abstract: 

The incidence of fungal endophthalmitis, a devastating sight threatening condition has increased dramatically in the recent years. It is important to identify fungal endophthalmitis accurately in order to initiate appropriate treatment. However, this job is often difficult by the use of conventional techniques like microscopy and culture. Molecular diagnosis plays a helpful role in this scenario as it has a higher analytical sensitivity in comparison to conventional techniques. The main aim of the study was to evaluate the role of a panfungal PCR in comparison to conventional microbiological techniques in reaching an etiological diagnosis of endophthalmitis. In our institution, all vitreous aspirate samples collected from suspected endophthalmitis patients are sent to the microbiology laboratory for etiological diagnosis. For the present study, vitreous aspirate samples from all patients with a clinical diagnosis of endophthalmitis where microscopy, culture as well as molecular tests were requested during the study period (from June 2012 to October 2013) were included in the analysis. The samples were collected from patients following standard procedure. Half of the vitreous was used for microscopy and inoculated in brain heart infusion broth and the other half was sent in a sterile glass vial. All samples were transported rapidly to the laboratory avoiding delay as much as possible. Apart of the sample was examined microscopically (Gram stain smear and KOH/calcofluor mount) and was plated into various media (for aerobic, anerobic bacteria and fungi) and incubated under appropriate conditions and duration. The remaining sample was used for DNA extraction and subsequent PCR. A total of 112 vitreous samples were included in the analysis. Out of these samples, eight (8/112-7.14%) showed fungal elements under microscope in KOH/calcofluor white preparation. The same eight also grew fungi in culture. In PCR, a much larger number 20/112 (17.86%) were positive for the panfungal genome. Being highly sensitive, PCR was able to confirm a fungal etiology in a significantly higher number of endophthalmitis cases thereby helping in the process of clinical decision making (like initiation of steroid etc.). The result is all the more significant as in many of these cases, a clinical suspicion of fungal etiology was not documented. Therefore, our findings show that in order to establish an etiological diagnosis of endophthalmitis, sensitive molecular tests like PCR must be used in conjunction with microscopy and culture. ‘Corresponding author E-mail: docanj [email protected]
2014

abstract No: 

OP-016

Full conference title: 

Society for Indian Human and Animal Mycologists 2014