Conjunctival Commensal Isolation and Identification in Mice.

Area of Science:

• Ophthalmology
• Microbiology
• Immunology

Background:

• The ocular surface was historically considered sterile.
• Recent findings suggest a low-level, persistent commensal bacterial presence.
• Identifying these bacteria is challenging due to low abundance and methodological limitations.

Purpose of the Study:

• To develop a robust and sensitive method for isolating and identifying bacterial species from the ocular surface.
• To overcome limitations of existing culture-based and DNA sequencing methods.
• To enable the study of commensal diversity in ocular health and disease.

Main Methods:

• A novel swab-based technique using a thin, in-laboratory-made swab targeting the lower conjunctiva.
• Incorporation of an amplification step for aerobic and facultative anaerobic bacterial genera.
• Building upon standard microbiological culturing techniques for enhanced sensitivity.

Main Results:

• Successful isolation and identification of common conjunctival species, including Corynebacterium spp., Coagulase-Negative Staphylococcus spp., and Streptococcus spp.
• Demonstrated the robustness and sensitivity of the developed protocol.
• Established a method suitable for defining commensal diversity in mice under various disease conditions.

Conclusions:

• The new method provides a reliable approach for studying the ocular surface microbiome.
• This technique enhances the ability to detect and characterize low-abundance commensal bacteria.
• The protocol is valuable for research into ocular health, disease, and the impact of different conditions on the conjunctival microbiome.