Abstract
Purpose :
To investigate the bacterial flora of the lacrimal sac and conjunctiva in patients with chronic dacryocystitis by 16S rRNA metagenomic analysis.
Methods :
Four patients (4 females, mean age 70.5 ± 9.1 years) with unilateral chronic dacryocystitis who visited the Department of Ophthalmology, Nagasaki University Hospital between March 2022 and March 2023 were included in this study. DNA was extracted from lacrimal sac contents and conjunctival swab fluid collected from both sides, and 16S rRNA metagenomic analysis of conjunctival bacterial flora was performed by next-generation sequencing to analyze the composition of bacterial flora.
Results :
The detected bacteria were classified into 24 phyla. The percentages of the top four genera, Firmicutes, Proteobacteria, Actinobacteria, and Proteobacteria, were 62.6%, 32.0%, 4.6%, and 0. 6% in the affected lacrimal sac, 16.2%, 65.1%, 16.1%, and 1.6% in the healthy lacrimal sac, 36.6%, 56.6%, 5.9%, and 0.6% in the affected conjunctiva, and 2.5%, 89.1%, 7.0%, and 0.9% in the healthy conjunctiva, respectively. The species were further classified into 449 genera. The top 10 genera were Burkholderia, Staphylococcus, Pseudomonas, unknown genus (Neisseriaceae), Propionibacterium, Agrobacterium, Delftia, Streptococcus, Saccharopolyspora, and Janthinobacterium. Alpha diversity at the genus level was highest in the healthy lacrimal sac and was significantly higher than in the affected lacrimal sac, affected conjunctiva, and healthy conjunctiva (Shannon index).
Conclusions :
The bacterial flora of chronic dacryocystitis was investigated by 16S rRNA metagenomic analysis, which showed that Firmicutes and Proteobacteria were abundant in the contents of chronic dacryocystitis, but their proportion was different from that of the healthy lacrimal sac. Alpha diversity was significantly lower in the affected than in the healthy lacrimal sac.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.