Simple large-scale quantitative phenotyping and antimicrobial susceptibility testing with Q-PHAST.

Area of Science:

• Microbiology
• Genomics
• Bioinformatics

Background:

• Characterizing antimicrobial susceptibility and phenotypes in microbial isolates is crucial for research and clinical settings.
• High-throughput robotic systems offer efficiency but are often cost-prohibitive for standard laboratories.

Purpose of the Study:

• To develop a cost-effective, scalable solution for quantitative phenotyping and antimicrobial susceptibility testing (AST) in standard microbiology laboratories.
• To enable non-experts with limited resources to perform accurate, large-scale microbial strain analysis.

Main Methods:

• Developed Q-PHAST (Quantitative PHenotyping and Antimicrobial Susceptibility Testing) using affordable materials and open-source software.
• Utilized deep 96-well plates for colony growth, with diluted aliquots spotted onto experimental plates with specific substances.
• Employed inexpensive flatbed scanners for real-time growth monitoring (images every 15 min) and analyzed data with a Python-based software.

Main Results:

• Q-PHAST provides accurate quantitative measures of microbial growth, fitness (e.g., doubling rate), and susceptibility (e.g., minimum inhibitory concentration).
• The system requires minimal hands-on time (<120 min/day for 3 days) and delivers ready-to-use results.
• Enables parallel phenotyping of hundreds of microbial strains, making advanced analysis accessible.

Conclusions:

• Q-PHAST offers a unique, affordable, and accessible solution for large-scale microbial phenotyping and antimicrobial susceptibility testing.
• This method empowers standard microbiology laboratories to conduct high-throughput quantitative analyses without prohibitive costs.
• Facilitates broader research and clinical applications by democratizing access to advanced microbial characterization techniques.