Abstract
Purpose :
Post-fever retinitis (PFR) is an inflammatory disease of the retina which manifests between 2 to 4 weeks after the fever. The major challenge is to identify the infectious etiology associated with PFR patients. Routine diagnostic approaches are not very successful. The present study is an attempt to identify the microorganisms associated with PFR by metagenomic approach.
Methods :
Metagenome was generated for DNA/cDNA extracted from vitreous body of individuals suffering from PFR (PFR, n=6) on the Illumina HiSeq2500 platform using paired-end sequencing. Non infectious vitreous sample served as control (C, n=10). More than 91% of the reads qualified Q25. The quality filtered raw reads were mapped to human genome and unmapped reads were considered to identify bacteria, fungi and viral taxonomy distribution among the samples. Comparative metagenome analysis of control with PFR samples was performed by MEGAN V5.11.3 by applying standard statistical analysis.
Results :
Metagenome sequencing revealed presence of bacteria, fungi and viruses in PFR and control samples. Unique or rare microorganisms associated with PFR were identified by filtering the metagenome of PFR with the core microbiome generated for the control samples. Further, RAPsearch2 analysis revealed presence of viral species of family Herpesviridiae, bacterial species such as Staphylococcus aureus, Streptococcus spp., Alcanivorax hongdengensis, Enterobacter cloacae, Peptoclostridium difficile,Klebsiella pneumonia and Chlamydia psittaci and the fungi such as Candida spp., and Saccharomyces cerevisiae.
Conclusions :
Principal coordinates analysis and 2D heatmap analysis revealed distinct cluster for PFR and control samples suggestive of variations in their microbiome composition. MEGAN based rare microbiome analysis identified putative pathogens in PRF samples (Table. 1).
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.