Abstract
Purpose:
All mucosal sites in the human body host a dynamic microbiome. The ocular surface microbiome has been incompletely characterized. We applied Biome Representational in Silico Karyotyping (BRiSK), a representational deep DNA sequencing technique, to the upper and lower lid conjunctiva of both eyes of 9 healthy subjects.
Methods:
Conjunctiva were swabbed using forensic DNA recovery swabs. DNA was purified and subjected to PCR for human actin gene, 16S rDNA PCR, and analyzed by BRiSK. 33 bp DNA sequence tags from BRiSK were compared to a comprehensive database for species identification. Suspected organisms' presence was confirmed by independent PCR.
Results:
High quality DNA was obtained from 27 of 36 samples as judged by actin PCR and BRiSK karyoptype. Significant 16S amplification was observed in only 5 samples, from 3 individuals. BRiSK revealed multiple sequence tags corresponding to the small anellovirus Torque Teno virus (TTV) in 5 samples from 3 individuals. Only one sample was positive for both 16S and TTV. PCR for TTV was strongly positive in 10 samples from five individuals, including all 5 samples positive by BRiSK. TTV was bilateral in four individuals, and found predominantly in samples from the upper lid.
Conclusions:
The ocular surface microbiome of the healthy conjunctiva contains limited amounts of bacteria. Torque teno virus DNA is found frequently and abundantly on the ocular surface of healthy subjects.
Keywords: 474 conjunctiva •
593 microbial pathogenesis: clinical studies •
475 conjunctivitis