What is the typical turnaround time difference between conventional culture-based AST and rapid diagnostic tests for bloodstream infections?

• A. Conventional AST typically requires 24-48 hours after culture positivity; rapid diagnostics can provide results within 1-6 hours of culture positivity.
• B. Conventional AST 3-4 days; rapid 5-7 days.
• C. Conventional AST 1-2 hours; rapid 24 hours.
• D. Conventional AST same as rapid.

Answer: (A)

Turnaround time for bloodstream infection testing hinges on how quickly you can move from a positive culture to a usable susceptibility result. Conventional culture-based AST requires the organism to be grown and then tested for susceptibility, which typically takes about 24 to 48 hours after the culture becomes positive. Rapid diagnostic tests use faster approaches—molecular methods, rapid identification, and quick phenotypic assays—so they can deliver susceptibility information within roughly 1 to 6 hours after culture positivity. The big takeaway is that rapid diagnostics substantially cut down the time to an actionable result compared with conventional methods, enabling earlier targeted therapy.