June 2021
Volume 62, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2021
Tear metabolite expression in bacterial keratitis: Outcomes of an untargeted approach
Gauri Shankar Shrestha; Ajay Kumar Vijay; Fiona Stapleton; Andrew JR White; Russell Pickford; Nicole Ann Carnt
Author Affiliations & Notes
  • Gauri Shankar Shrestha
    School of Optometry and Vision Science, The University of New South Wales, Sydney, New South Wales, Australia
    Ophthalmology, Institute of Medicine, Maharajgunj Medical Campus, Kathmandu, Bagmati, Nepal
  • Ajay Kumar Vijay
    School of Optometry and Vision Science, The University of New South Wales, Sydney, New South Wales, Australia
  • Fiona Stapleton
    School of Optometry and Vision Science, The University of New South Wales, Sydney, New South Wales, Australia
  • Andrew JR White
    Department of Ophthalmology, Westmead Hospital, University of Sydney, Sydney, New South Wales, Australia
    Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia
  • Russell Pickford
    Bioanalytical Mass Spectrometry Facility, UNSW Sydney, University of New South Wales, Sydney, New South Wales, Australia
  • Nicole Ann Carnt
    School of Optometry and Vision Science, The University of New South Wales, Sydney, New South Wales, Australia
    Westmead Institute for Medical Research, University of Sydney, Sydney, New South Wales, Australia
  • Footnotes
    Commercial Relationships   Gauri Shrestha, None; Ajay Kumar Vijay, None; Fiona Stapleton, None; Andrew White, None; Russell Pickford, None; Nicole Carnt, None
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science June 2021, Vol.62, 1948. doi:
  • Views
  • Share
  • Tools
    • Alerts
      User Alerts
      You are adding an alert for:
      Tear metabolite expression in bacterial keratitis: Outcomes of an untargeted approach
      You will receive an email whenever this article is corrected, updated, or cited in the literature. You can manage this and all other alerts in My Account
      The alert will be sent to:
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation
      Citation

      Gauri Shankar Shrestha, Ajay Kumar Vijay, Fiona Stapleton, Andrew JR White, Russell Pickford, Nicole Ann Carnt; Tear metabolite expression in bacterial keratitis: Outcomes of an untargeted approach. Invest. Ophthalmol. Vis. Sci. 2021;62(8):1948.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

      ×
    • Get Permissions
  • Supplements
Abstract

Purpose : To identify and characterise tear metabolites expression in participants with bacterial keratitis and compare these to expression in healthy controls.

Methods : Twelve tear samples were received from participants with bacterial keratitis (n = 6) at initial presentation and age (case: median age = 59; control: median age = 52; P = 0.44) and sex (case: male:female = 2:4; control: male:female = 3:3; P = 0.70) matched healthy controls (n = 6). Metabolites underwent methanol extraction from the tear samples, chromatographic separation using the Ultimate 3000 System, along with C18 Column, and Mass Spectrometry using QExactive HF. Compound discoverer software v3.1 was used for data analysis. Differential analysis was used to explore fold-change and ratio between cases and controls. The difference in m/z features was adjusted using the Benjamini-Hochberg (B-H) correction for false discovery rate (FDR) with q = 0.05.

Results : Of six cases with bacterial keratitis, two were culture negative and four were culture positive for S. lugdunensis, S. pneumonia, Multidrug-resistant S. aureus or M. lacunata. Of 47 metabolites differentially expressed, 25 were upregulated, and 22 were downregulated in the cases compared to controls. Phenylalanyl-lysin (Log2 fold-change = 11, Padj. < 0.0001) and adenine (Log2 fold-change = -6.4, Padj. < 0.0001) were the most upregulated or downregulated metabolites in the study, respectively. Purine, tryptophan and amino acid metabolism pathways were primarily observed in tears of participants with bacterial keratitis.

Conclusions : A wide range of tear metabolites was detected in tears of participants with bacterial keratitis. Biologically plausible differences between several metabolite classes such as amino acids, indoles, carbohydrates and nucleosides were observed in tears of participants with bacterial keratitis compared to healthy controls.

This is a 2021 ARVO Annual Meeting abstract.

 

Figure 1. Volcano-plot showing 41 metabolites significantly detected in C18 reverse-phase positive-ion mode. seven metabolites were detected in C18 reverse-phase negative-ion mode. Of 41 metabolites, 21 were upregulated and 18 were down-regulated in the tears of participants with bacterial keratitis than in the tears of healthy controls.
View OriginalDownload Slide

Figure 1. Volcano-plot showing 41 metabolites significantly detected in C18 reverse-phase positive-ion mode. seven metabolites were detected in C18 reverse-phase negative-ion mode. Of 41 metabolites, 21 were upregulated and 18 were down-regulated in the tears of participants with bacterial keratitis than in the tears of healthy controls.

Figure 1. Volcano-plot showing 41 metabolites significantly detected in C18 reverse-phase positive-ion mode. seven metabolites were detected in C18 reverse-phase negative-ion mode. Of 41 metabolites, 21 were upregulated and 18 were down-regulated in the tears of participants with bacterial keratitis than in the tears of healthy controls.

Figure 1. Volcano-plot showing 41 metabolites significantly detected in C18 reverse-phase positive-ion mode. seven metabolites were detected in C18 reverse-phase negative-ion mode. Of 41 metabolites, 21 were upregulated and 18 were down-regulated in the tears of participants with bacterial keratitis than in the tears of healthy controls.
View OriginalDownload Slide

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Attribution-NonCommercial-NoDerivatives
Copyright © 2025 Association for Research in Vision and Ophthalmology.
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×
This site uses cookies. By continuing to use our website, you are agreeing to our privacy policy.Accept