背景:蠕形螨性眼睑炎(DB)是一种常见的眼表疾病。蠕形螨感染后睫毛根中细菌群落的特征仍然未知。了解DB患者睫毛毛囊细菌群落特征,可为指导DB的诊断和治疗提供有价值的见解。
方法:本研究纳入了25例DB患者(DB组)和21例非DB志愿者(对照组)。对右眼上眼睑的睫毛进行了采样,和16S核糖体DNA(rDNA)测序以确定侵染1个月内微生物16SrDNA基因的V3-V4区域。分析比较两组的测序数据。使用从DB组中的12名DB患者中获得的蠕形螨评估了伯克霍尔德菌对蠕形螨的存活的影响。
结果:在DB组和对照组中总共鉴定出31个门和862个属。两组中五个最丰富的门是变形杆菌,Firmicutes,放线菌,拟杆菌和蓝细菌。DB组放线菌丰度明显高于对照组。在属一级,两组中最丰富的五个属是假单胞菌属,伯克霍尔德菌-卡瓦列尼亚-帕拉布尔霍尔德菌,劳氏菌和不动杆菌;对照组中严格梭状芽胞杆菌1丰富,DB组中棒状杆菌1丰富。与对照组相比,在DB组中,伯克霍尔德菌-卡波列菌-Paraburkholderia的丰度低2.36倍.线性判别分析效应大小(LEfSe)分析显示伯克霍尔德菌-卡波隆菌-帕拉布尔霍尔德菌,SC_I_84_未分类,非粘细菌和丁香弧菌是对照组的主要生物标志物,副杆菌属和落叶草科NK4A136组是DB组的主要生物标志物。为了探索这些最佳标记模型的性能,进行了接收机工作特性曲线分析,伯克霍尔德菌-卡波列菌-帕拉布尔霍尔德菌的平均曲线下面积为0.7448。从正常人睫毛中分离出的洋葱伯克霍尔德菌被发酵,将从患者睫毛中分离的蠕形螨与发酵上清液一起培养。结果表明,发酵上清液能显著降低蠕形螨的存活时间,表明这种细菌对蠕形螨的潜在治疗价值。
结论:DB患者的睫毛中细菌群落的组成与健康志愿者的睫毛中细菌群落的组成不同,显示感染睫毛的细菌多样性减少。这种减少可能与DB的发生和发展有关。发现洋葱伯克霍尔德菌培养基上清液抑制睫毛毛囊中蠕形螨的生长,为蠕形螨感染的临床治疗提供了具有潜在应用的新见解。
BACKGROUND: Demodex blepharitis (DB) is a common disease of the ocular surface. The characteristics of the bacterial community in eyelash roots after Demodex infestation are still unknown. Knowledge of the characteristics of the bacterial community of eyelash follicles in patients with DB can provide valuable insights for guiding the diagnosis and treatment of DB.
METHODS: Twenty-five patients with DB (DB group) and 21 non-DB volunteers (control group) were enrolled in the study. Eyelashes from the upper eyelid of the right eye were sampled, and 16S ribosomal DNA (rDNA) sequencing was performed to determine the V3-V4 regions of the microbial 16S rDNA gene within 1 month of infestation. The sequencing data of the two groups were analyzed and compared. The effect of the bacterium Burkholderia on the survival of Demodex mites was evaluated using Demodex obtained from 12 patients with DB other that the patients in the DB group.
RESULTS: A total of 31 phyla and 862 genera were identified in the DB and control groups. The five most abundant phyla in the two groups were Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Cyanobacteria. The abundance of Actinomycetes was significantly higher in the DB group than in the control group. At the genus level, the five most abundant genera in the two groups were Pseudomonas, Burkholderia-Caballeronia-Paraburkholderia, Rolstonia and Acinetobacter; Clostridium sensu stricto 1 was abundant in the control group and Corynebacterium_1 was abundant in the DB group. Compared with the control group, the abundance of Burkholderia-Caballeronia-Paraburkholderia was 2.36-fold lower in the DB group. Linear discriminant analysis Effect Size (LEfSe) analysis revealed Burkholderia-Caballeronia-Paraburkholderia, SC_I_84_unclassified, Nonmyxobacteria and Succinvibrio to be the major biomarkers in the control group and Catenibacterium and Lachnospiraceae NK4A136 group to be the major biomarkers in the DB group. To explore the performance of these optimal marker models, receiver operational characteristic curve analysis was performed, and the average area under the curve value of Burkholderia-Caballeronia-Paraburkholderia was 0.7448. Burkholderia cepacia isolated from normal human eyelashes was fermented, and the Demodex mites isolated from patient eyelashes were cultured together with its fermented supernatant. The results showed that the fermentation supernatant could significantly reduce the survival time of the Demodex mites, suggesting the potential therapeutic value of this bacterium against Demodex.
CONCLUSIONS: The composition of the bacterial community in the eyelashes of DB patients differed from that in eyelashes of healthy volunteers, revealing a decrease in bacterial diversity in infested eyelashes. This decrease may be related to the occurrence and development of DB. The supernatant of Burkholderia cepacia culture medium was found to inhibit the growth of Demodex in eyelash hair follicles, providing a new insight with potential applications for the clinical treatment of Demodex infestation.