April 2014
Volume 55, Issue 13
Free
ARVO Annual Meeting Abstract  |   April 2014
Lipase production by ocular bacteria
Author Affiliations & Notes
  • Hua Zhu
    Brien Holden Vision Institute, Sydney, NSW, Australia
    Schoold of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
  • Keizo Watanabe
    Department of Ophthalmology,, Kinki University Faculty of Medicine, Osaka, Japan
  • Judith Flanagan
    Brien Holden Vision Institute, Sydney, NSW, Australia
    Schoold of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
  • Rani S Bandara
    Brien Holden Vision Institute, Sydney, NSW, Australia
  • Brien A Holden
    Brien Holden Vision Institute, Sydney, NSW, Australia
    Schoold of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
  • Eric Papas
    Brien Holden Vision Institute, Sydney, NSW, Australia
    Schoold of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
  • Footnotes
    Commercial Relationships Hua Zhu, None; Keizo Watanabe, None; Judith Flanagan, None; Rani Bandara, None; Brien Holden, None; Eric Papas, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science April 2014, Vol.55, 3676. doi:https://doi.org/
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Hua Zhu, Keizo Watanabe, Judith Flanagan, Rani S Bandara, Brien A Holden, Eric Papas; Lipase production by ocular bacteria. Invest. Ophthalmol. Vis. Sci. 2014;55(13):3676. doi: https://doi.org/.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose: Our previous study found that higher density of commensal bacteria on the eyelid is associated with clinical measures of decreased meibum quality and function. Changes in commensal bacterial profiles can result in altered expression of bacterial products such as lipases. Bacterial lipases might alter tear lipid spectrum and cause the increase of free fatty acids that are irritants to eyelid epithelia and may induce inflammation and hyperkeratinisation of meibomian orifice, contributing to development of blepharitis or meibomian gland dysfunction. The aim of the current study was to determine the levels of lipase production by various species of ocular bacteria.

Methods: Forty-eight isolates of most commonly isolated ocular commensal species Staphylococcus epidermidis (20 isolates), Propionibacterium acnes (8 isolates), and Staphylococcus aureus (20 isolates) were examined. Each test strain was cultured in 10 mL Tryptic Soy Broth at 37 oC for S. epidermidis and S. aureus, or in an anaerobic jar for P. acnes. After 24 h incubation, optical density of each culture was measured, and culture supernatants collected. Lipase activity in culture supernatant was determined by using a commercial lipase assay kit or tributyrin assay. Lipase activity for each test strain was normalized against bacterial growth. Bonferroni multiple comparison test in ANOVA was applied to compare the average lipase production among different species.

Results: All the test bacterial strains produced lipases. The levels of lipase production by different species were varied. The average of lipase production by S. aureus strains (2.37 ± 0.54 log units) was significantly higher than that of S. epidermidis (2.02 ± 0.37 log U, p = 0.038) and P. acnes (1.76 ± 0.14 log U, p = 0.004). Variation between strains in lipase production was also observed. The levels of lipase production ranged from 28 to 1711 U with median level of 266 U for S. aureus, from 38 to 543 U with median of 73 U for S. epidermidis, and from 30 to 87 U with median of 58 U for P. acnes.

Conclusions: The greatest bacterial lipolytic activity was found in the S. aureus ocular clinical isolates, and the levels of lipase production within this species were found to be strain specific. Whether high lipase production species or strains dominate to ocular microbiota in blepharitis or MGD related dry eye syndrome remains to be determined.

Keywords: 486 cornea: tears/tear film/dry eye  
×
×

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.

×