HALO384: a halo-based potency prediction algorithm for high-throughput detection of antimicrobial agents

Area of Science:

• Microbiology
• Drug Discovery
• Bioassay Development

Background:

• Screening chemical libraries for bioactive compounds is crucial for drug discovery.
• Existing methods for microbial bioactivity screening can be slow and costly.
• Accurate estimation of compound potency (EC50) is essential for identifying effective drug candidates.

Purpose of the Study:

• To develop and validate a high-throughput (HT) agar-based halo assay for rapid screening of microbial bioactivity.
• To establish a pattern recognition algorithm for analyzing halo shapes in optical density measurements.
• To assess the correlation between halo assay results and traditional EC50 measurements.

Main Methods:

• Development of a pattern recognition algorithm to detect halo-like shapes in plate reader optical density (OD) measurements.
• Implementation of an agar-based halo assay for high-throughput screening of chemical libraries.
• Screening of a 21,120-member drug-like compound library in Saccharomyces cerevisiae.
• Validation of the assay with the pathogenic bacterium Vibrio cholerae.

Main Results:

• The HT halo assay accurately estimates compound potency (EC50) based on total growth inhibition within detected halos.
• The novel halo recognition method significantly outperforms previous single-point OD reading methods.
• Screening identified novel bioactive scaffolds with varying potencies in Saccharomyces cerevisiae.
• A good correlation was observed between liquid culture EC50 values and halo scores in Vibrio cholerae.

Conclusions:

• The HT agar-based halo assay offers a rapid, inexpensive, and effective method for screening bioactivity in microorganisms.
• This assay facilitates the discovery of novel bioactive compounds and scaffolds.
• The method is applicable to both yeast and pathogenic bacteria, broadening its utility in microbial research and drug discovery.