PBC Separator with Selux AST System

The PBC Separator with Selux AST System is an automated inoculum preparation instrument that processes positive blood culture samples using lysis, centrifugation, and optical density measurements to create a standardized bacterial suspension. This suspension is then used with the Selux AST System to perform antimicrobial susceptibility testing on gram-negative and gram-positive bacteria, providing quantitative minimum inhibitory concentration (MIC) results under 7 hours from sample to result.

The subject device uses identical lysis, centrifugation, and sequential optical density measurement technology as the predicate to generate McFarland-equivalent suspensions. The only difference is expanded intended use to include both gram-negative and gram-positive organisms with additional antimicrobial agents and organism combinations, while maintaining the same output (liquid bacterial suspension), AST platform (Selux AST System), and operational principles as the predicate.

Not stated in this summary. The document references FDA-cleared continuous monitoring blood culture systems (BD BACTEC, bioMérieux BacT/ALERT 3D, bioMérieux Virtuo) and comparison to reference broth microdilution methods, but does not cite specific ISO, IEC, or ASTM consensus standards.

Substantial equivalence is established through identical core technology and principles: both devices use the same lysis, centrifugation, and optical density tuning methodology applied to positive blood cultures for the same intended purpose (inoculum preparation for AST). The candidate device demonstrates comparable or superior performance to the predicate across reproducibility (≥94% worst-case inter-site), clinical performance (99.5% essential agreement for Linezolid, 97.1% for Daptomycin), and compatibility with 11 blood culture bottle types. The expansion to gram-positive organisms represents a logical extension using the same hardware and process, supported by rigorous validation data showing >89.9% essential agreement across interferent testing and strong clinical correlation. Risk and safety profiles remain unchanged from the predicate.