Jayasudha Rajagopalaboopathi, Chakravarthy Sama Kalyana, Prashanthi Gumpili Sai, Sharma Savitri, Garg Prashant, Murthy Somasheila I, Shivaji Sisinthy
Prof. Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India.
The Cornea Institute, L V Prasad Eye Institute, Hyderabad, India.
Front Ophthalmol (Lausanne). 2022 May 5;2:894739. doi: 10.3389/fopht.2022.894739. eCollection 2022.
Inflammation of the cornea is known as keratitis, and bacteria, fungi, protozoans, and viruses are the etiological agents of this disease. Delayed treatment of keratitis could result in loss of vision and, under certain severity conditions, the removal of an eye and its associated structures. In the current study, the ocular surface (conjunctiva and cornea) mycobiomes of individuals with bacterial keratitis were compared with the ocular mycobiome (conjunctiva) of healthy individuals, free of any ocular morbidity. Mycobiomes were generated through NGS approach using conjunctival swabs and corneal scrapings as the source of DNA from which ITS2 was amplified and sequenced, as a proxy to identify fungi. The results indicated significant changes in the alpha-diversity indices and in the abundance at the phylum and genera level. Hierarchical clustering using a heatmap showed that the mycobiomes were different. Furthermore, NMDS plots also differentiated the mycobiomes in the three cohorts, implying dysbiosis in the mycobiomes of the conjunctivae and corneal scrapings of bacterial keratitis individuals compared to control individuals. A preponderance of negative interactions in the hub genera in the conjunctival swabs of bacterial keratitis individuals compared to healthy controls further re-emphasized the differences in the mycobiomes. The dysbiotic changes at the genera level in conjunctivae and corneal scrapings of bacterial keratitis individuals are discussed with respect to their possible role in causing or exacerbating ocular surface inflammation. These results demonstrate dysbiosis in the ocular mycobiome in bacterial keratitis patients compared to healthy controls for the first time.
角膜炎症被称为角膜炎，细菌、真菌、原生动物和病毒是这种疾病的病原体。角膜炎治疗延迟可能导致视力丧失，在某些严重情况下，还会导致眼球及其相关结构被摘除。在本研究中，将细菌性角膜炎患者的眼表（结膜和角膜）真菌群落与无任何眼部疾病的健康个体的眼部真菌群落（结膜）进行了比较。通过NGS方法，以结膜拭子和角膜刮片作为DNA来源，扩增并测序ITS2，以此作为鉴定真菌的替代方法，从而生成真菌群落。结果表明，α多样性指数以及门和属水平的丰度存在显著变化。使用热图进行的层次聚类显示真菌群落不同。此外，NMDS图也区分了三个队列中的真菌群落，这意味着与对照个体相比，细菌性角膜炎患者结膜和角膜刮片的真菌群落存在失调。与健康对照相比，细菌性角膜炎患者结膜拭子中枢纽属的负相互作用占优势，这进一步强调了真菌群落的差异。讨论了细菌性角膜炎患者结膜和角膜刮片中属水平的失调变化在引起或加重眼表炎症方面可能发挥的作用。这些结果首次证明，与健康对照相比，细菌性角膜炎患者的眼部真菌群落存在失调。
