16S rRNA sequencing in chronic dacryocystitis

The pathogenesis of chronic dacryocystitis (CDC) is associated with a variety of bacteria. Investigating microflora has the potential to provide a theoretical basis for preventing and treating CDC. 16S rRNA sequencing is a sequence-based bacterial analysis. The application of 16S rRNA sequencing in CDC is rarely reported. A case-control study of infected and healthy eyes diagnosed as CDC patients was conducted. Seventy-eight patients were divided into A (conjunctival sac secretions from healthy eyes), B (conjunctival sac secretions from affected eyes), and C (lacrimal sac secretions from affected eyes) groups. The flora of samples was analysed with 16S rRNA sequencing, and the data was analysed using QIIME, R, LefSE and other software. The potential functions were analysed by PICRUSt. A total of 1440 operational taxonomic units (OTUs) were obtained, 139 specific to group A, 220 specific to group B, and 239 specific to group C. There was no significant difference in α index between the three groups. The beta diversity and grouping analysis data indicated that the three groups of flora were similar in species richness and diversity, but there were some differences in composition. In group A, the abundance of <i>Pseudomonadaceae, Chlorobacteria, Moraceae, Staphylococcaceae, Bacillariophyceae, Immunobacterium spp</i>. and <i>Bacillus spp</i>. was higher; in group B, the abundance of <i>Burkholderiaceae, Sphingomonas, Rhizobia, Stalked Bacteria, Sphingomonadaceae, Enterobacteriaceae, Shortwaveomonas spp</i>. was higher; in group C, the abundance of <i>Streptococcus digestiveis, Propionibacterium, Enterobacteriaceae, Anaerobacteriaceae, Propionibacteriaceae, Bacillus spp. Neisseria spp</i>. and <i>Shortactomonas spp</i>. was higher. Six pathways were identified to assess the potential microbial functions. Alterations in the microbiota of the conjunctiva and lacrimal sac are associated with the pathogenesis of CDC, which may provide certain guidance for antibiotic treatment of CDC.

慢性泪囊炎（chronic dacryocystitis, CDC）的发病机制与多种细菌密切相关，对其菌群结构的探究可为该病的防治提供理论依据。16S rRNA测序（16S rRNA sequencing）是一种基于序列的细菌分析手段，目前其在CDC领域的应用报道较为匮乏。本研究开展了一项针对确诊CDC患者的感染眼与健康眼的病例对照研究，共纳入78例患者，将其样本分为三组：A组（健康眼结膜囊分泌物）、B组（患眼结膜囊分泌物）、C组（患眼泪囊分泌物）。通过16S rRNA测序对各组样本的菌群进行分析，并采用QIIME、R、LefSE等软件完成数据处理，同时借助PICRUSt预测菌群的潜在功能。本研究共获得1440个操作分类单元（operational taxonomic units, OTUs），其中A组特有139个，B组特有220个，C组特有239个。三组样本的α多样性指数无显著差异；β多样性与分组分析结果显示，三组菌群的物种丰富度与多样性水平相近，但群落组成存在一定差异。具体而言，A组中假单胞菌科（Pseudomonadaceae）、绿细菌门（Chlorobacteria）、桑科（Moraceae）、葡萄球菌科（Staphylococcaceae）、硅藻纲（Bacillariophyceae）、免疫杆菌属（Immunobacterium spp.）以及芽孢杆菌属（Bacillus spp.）的丰度更高；B组中伯克霍尔德菌科（Burkholderiaceae）、鞘氨醇单胞菌属（Sphingomonas）、根瘤菌属（Rhizobia）、有柄细菌（Stalked Bacteria）、鞘氨醇单胞菌科（Sphingomonadaceae）、肠杆菌科（Enterobacteriaceae）、短波单胞菌属（Shortwaveomonas spp.）的丰度更高；C组中消化链球菌（Streptococcus digestiveis）、丙酸杆菌属（Propionibacterium）、肠杆菌科（Enterobacteriaceae）、厌氧杆菌科（Anaerobacteriaceae）、丙酸杆菌科（Propionibacteriaceae）、芽孢杆菌属（Bacillus spp.）、奈瑟菌属（Neisseria spp.）以及短杆菌属（Shortactomonas spp.）的丰度更高。本研究共鉴定出6条通路用于评估潜在微生物功能。结膜与泪囊菌群的结构改变与CDC的发病机制密切相关，该研究结果可为CDC的抗生素临床治疗提供一定指导。