Evaluation of the BIOGRAM antimicrobial susceptibility test system

Area of Science:

• Clinical Microbiology
• Infectious Diseases
• Diagnostic Technology

Background:

• Accurate antimicrobial susceptibility testing (AST) is crucial for guiding effective antibiotic treatment.
• Disk diffusion methods offer a standardized approach to AST, but interpretation can be complex.
• The BIOGRAM system aims to automate MIC interpretation from disk diffusion zone diameters.

Purpose of the Study:

• To evaluate the performance of the BIOGRAM system for determining Minimum Inhibitory Concentrations (MICs).
• To compare BIOGRAM results against the established broth microdilution reference method.
• To assess BIOGRAM's accuracy with a diverse range of clinically relevant bacterial pathogens.

Main Methods:

• The BIOGRAM system was challenged with 511 clinical isolates.
• Isolates included Enterobacteriaceae, nonfermentative gram-negative bacteria, staphylococci, and enterococci.
• Results were compared to broth microdilution, with 10,085 organism-drug combinations evaluated.

Main Results:

• BIOGRAM demonstrated high overall agreement with the broth microdilution method.
• An overall correlation of 95.9% was achieved.
• Appropriate control organisms were used throughout the testing series.

Conclusions:

• The BIOGRAM system provides accurate MIC determination from disk diffusion zone diameters.
• BIOGRAM is a reliable tool for antimicrobial susceptibility testing in clinical microbiology.
• The system shows excellent correlation with the reference broth microdilution method, supporting its clinical utility.