Rapid antimicrobial susceptibility testing from positive blood cultures: platform review
Microbiology Research (MDPI) · 2026
ReviewExternal link only
Curated peer-reviewed / authoritative reference. Open the source link for the full text.
Antimicrobial Resistance
Antimicrobial Susceptibility Testing (AST)
Phenotypic determination of which antimicrobials will work against a patient's isolate — the front line of the response to antimicrobial resistance.
Method
Disk diffusion, MIC (broth dilution / E-test)
Turnaround
Data to be updated
Specimen
Data to be updated
Sample volume
Data to be updated
Why This Test Matters
Antimicrobial resistance develops when pathogens evolve to survive drugs. Diagnostic delay forces prolonged empirical broad-spectrum therapy, which itself drives resistance. Rapid, accurate susceptibility data enable targeted therapy, support antimicrobial stewardship and improve outcomes.
Clinical Background
Resistance arises through mutation and horizontal gene transfer (e.g., mecA, vanA, carbapenemases). Empirical therapy is a clinical necessity in severe infection — but it must be narrowed as soon as laboratory evidence arrives.
The Diagnostic Challenge
Current Diagnostic Methods
Phenotypic AST measures actual growth inhibition: disk diffusion (zone of inhibition), MIC determination by broth/agar dilution or E-test. Molecular methods detect resistance genes (e.g., by PCR, LPA or WGS) and predict — but do not measure — resistance.
How the ID Labs Test Helps
ID Labs provides disk diffusion and MIC-based susceptibility testing with interpretation against current CLSI/EUCAST standards, and molecular resistance-marker detection where rapid answers are needed.
Test Methodology
MethodologyDisk diffusion, MIC (broth dilution / E-test)
TechnologyPhenotypic AST
InstrumentData to be updated
DetectionData to be updated
Specimen Information
Specimen requirements: data to be updated. Please contact ID Labs.
Specimen Container
Container information: data to be updated.
Targets / Analytes / Organisms
Validated target list: data to be updated. Please contact ID Labs for the current configuration.
Technical Performance
| Characteristic | Value | Source |
|---|---|---|
| Analytical / clinical performance | Performance characteristics: please contact ID Labs — data to be updated. | ID Labs Validated Performance |
Clinical Utilization
Advantages
- Directly measures drug activity against the patient's isolate
- Quantitative MIC guides dosing
- Interpreted against current international breakpoints
- Feeds antimicrobial stewardship programmes
Limitations
- Requires a cultured isolate (24–72 h after culture)
- Breakpoint interpretation depends on the current standard version
- Phenotypic and genotypic resistance are related but not always identical — a detected resistance gene predicts, but does not measure, resistance
- Quality control and inoculum standardisation are critical
Conventional vs Advanced Technology
| Phenotypic AST vs Molecular AMR detection | ||
|---|---|---|
| Feature | Phenotypic AST | Molecular resistance testing |
| Measures | Actual growth inhibition (MIC/zone) | Presence of resistance genes/mutations |
| Requires isolate | Yes | No — can run on direct specimens |
| Speed | Days (after culture) | Hours |
| Coverage | Any drug tested | Only known markers |
| Guides | Definitive therapy & dosing | Early escalation/de-escalation |
Publications & Scientific Evidence
Genotypic and phenotypic strategies for rapid antimicrobial susceptibility testing
Antibiotics (MDPI) · 2024
ReviewExternal link only
Curated peer-reviewed / authoritative reference. Open the source link for the full text.
Related Tests & Technologies
Discuss this test with our scientific team
Panel configuration, specimen logistics and turnaround details on request.
Information on this page is educational and does not replace professional clinical judgment. Performance values are labelled by source (ID Labs Specification / ID Labs Validated Performance / Manufacturer Specification / Published Scientific Evidence). Molecular results must be correlated clinically and, where appropriate, confirmed by culture and phenotypic susceptibility testing.