Alterations in the conjunctival surface bacterial microbiome in bacterial keratitis patients. (February 2021)

• Record Type: Journal Article
• Authors: Shivaji, Sisinthy; Jayasudha, Rajagopalaboopathi; Chakravarthy, Sama Kalyana; SaiAbhilash, Chinthala Reddy; Sai Prashanthi, Gumpili; Sharma, Savitri; Garg, Prashant; Murthy, Somasheila I.
• Is Part Of: Experimental eye research. Volume 203(2021)
• Publication Date: 2021-02
• Subjects: Bacterial keratitis -- Ocular bacterial microbiome -- Conjunctiva -- Cornea -- Dysbiosis -- NGS; HC Healthy controls -- BK Bacterial keratitis -- HC-SW Conjunctival swabs of healthy control -- BK-SW Conjunctival swabs of bacterial keratitis -- BK-CR Corneal scrapings of bacterial keratitis; Ophthalmology -- Periodicals; Eye -- Periodicals; Œil -- Périodiques; Ophthalmology; Periodicals; Electronic journals; 612.8405
• DOI: 10.1016/j.exer.2020.108418
• Languages: English
• ISSNs: 0014-4835

Abstract

Abstract: Microbial keratitis is an infectious disease of the eye, in which the cornea is inflamed. Under severe conditions, keratitis can lead to significant loss of vision and enucleation of the eye. Ocular trauma is the major risk factor causing keratitis and microorganisms viz ., bacteria, fungi, viruses are the causative agents. The current study characterized the conjunctival bacterial microbiomes of healthy individuals and individuals with bacterial keratitis (BK) and assessed whether ocular microbiome dysbiosis is prevalent in BK patients. Ocular bacterial microbiomes were generated from the conjunctival swabs of healthy controls (HC-SW) and conjunctival swabs (BK-SW) and corneal scrapings (BK-CR) of BK patients using V3–V4 amplicon sequencing and data analysed using QIIME and R software. The Alpha diversity indices, diversity and abundance of different phyla and genera, heat map analysis, NMDS plots and inferred functional pathway analysis clearly discriminated the bacterial microbiomes of conjunctival swabs of healthy controls from that of BK patients. Preponderance of negative interactions in the hub genera were observed in BK-CR and BK-SW compared to HC-SW. In addition, a consistent increase in the abundance of pathogenic bacteria, as inferred from published literature, was observed in the conjunctiva of BK patients compared to HC and this may be related to causing or exacerbating ocular surface inflammation. This is the first study demonstrating dysbiosis in the ocular bacterial microbiome of conjunctiva of bacterial keratitis patients compared to the eye of healthy controls. The bacterial microbiome associated with the corneal scrapings of keratitis individuals is also described for the first time. Highlights: Demonstrates dysbiosis in the ocular bacterial microbiome in BK patients. Pathogenic bacteria are predominant in ocular surface of BK patients. Increase in pathogenic bacteria in BK patients may support inflammation.