High-throughput quantitative method for assessing coaggregation among oral bacterial species.

Area of Science:

• Microbiology
• Biofilm formation
• Bacterial interactions

Background:

• Coaggregation between bacterial species is crucial for the development of multi-species biofilms.
• Previous limitations in quantifying coaggregation have hindered mechanistic studies.
• Oral bacteria like Streptococcus gordonii, Streptococcus oralis, and Actinomyces oris exhibit well-characterized coaggregation patterns.

Purpose of the Study:

• To develop and compare two quantitative methods for screening and analyzing bacterial coaggregation.
• To assess the utility of a microplate reader and FlowCam(™) real-time imaging for coaggregation studies.
• To provide tools for high-throughput screening and in-depth analysis of autoaggregation and coaggregation.

Main Methods:

• A microplate-based assay was used to quantify cell density for coaggregation scoring 60 minutes postmixing.
• High-speed real-time imaging with FlowCam(™) was employed to measure the rate of coaggregation over time.
• Results from both methods were compared against visual coaggregation scores and microscopic observations using oral bacteria.

Main Results:

• Both microplate and FlowCam(™) methods showed strong correlation with visual coaggregation scores.
• The microplate assay proved effective for high-throughput screening of coaggregating bacterial pairs.
• The FlowCam(™) assay provided detailed quantification of coaggregation rates and aggregate formation.

Conclusions:

• Two complementary quantitative methods, a microplate assay and FlowCam(™) imaging, have been successfully demonstrated for bacterial coaggregation studies.
• These assays overcome previous limitations in rapid and reproducible quantification, facilitating mechanistic investigations.
• The developed methods enable both high-throughput screening and in-depth analysis, paving the way for future research on large bacterial panels.