Metagenomic Profile of the Lacrimal Sac Microbial Communities in Congenital Nasolacrimal Duct Obstruction: The Lacriome Paper 7.

Abstract

Purpose: To study the metagenomics of microbes isolated from the lacrimal sacs of patients with congenital nasolacrimal duct obstruction (CNLDO).

Methods: A prospective study was performed on 10 consecutive lacrimal sac samples obtained for the metagenomic analysis from the patients with CNLDO who underwent endoscopic dacryocystorhinostomy at a tertiary care dacryology service. Immediately after a full-length lacrimal sac marsupialization, the samples were collected and transported on ice to the laboratory. A whole shotgun metagenome sequencing was performed on the Illumina platform following DNA extraction and library preparation. The downstream processing and bioinformatics of the samples were performed using multiple software packaged in the SqueezeMeta pipeline, and the functional annotation was performed using the MetaCerberus, v1.3.1.

Results: The taxonomic hit distribution across the samples showed that bacteria were the most common isolates, followed by fungi and viruses. The major bacterial phyla identified across the samples of CNLDO were proteobacteria, firmicutes, actinobacteria, and bacteroidetes. The prevalent organisms include Haemophilus influenzae, Streptococcus pneumoniae, Stenotrophomonas maltophilia, Achromobacter xylosoxidans, Staphylococcus aureus, and Ochrobactrum anthropi, among others. The predominant fungal species identified include Botrytis cinerea, Aspergillus oryzae, and Fusarium fujikuroi. Several species of pandoravirus were the common viruses recognized.

Conclusions: This is the first whole metagenome sequencing of the lacrimal sac contents from patients with CNLDO, which showed that the sacs harbored diverse microbial communities of bacteria, fungi, and viruses. Further work is needed to decipher the polymicrobial interactions and their relationship with CNLDO.