(13 days)
MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panel is used to determine quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic Gram-Negative bacilli (Enterobacteriaceae, glucose non-fermenters, and non-Enterobacteriaceae glucose (Enterouters) After inoculation, panels are read on the WalkAway® S/ System or equivalent (upgraded WalkAway® 40 or WalkAway® 96) according to the Package Insert.
This particular submission is for the antimicrobial Imipenem on the Synergies plus™ Gram-Negative MIC/Combo Panels.
MicroScan® rapID/S plus™ Gram-Negative MIC/Combo Panels are designed for use in determining quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic gram-negative bacilli. The MicroScan® rapID/S plus™ Cram-Negative MIC/Combo Panels are read on the WalkAway® S7 System or equivalent (upgraded WalkAway® 40 or WalkAway® 96 instruments).
The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test that have been diluted in Mueller-Hinton Broth to concentrations bridging the range of clinical interest and are presented in micro-titer wells in dried form. rapID/S plus™ panels are inoculated with a standardized suspension of the organism and incubated at 35℃ in the WalkAway® SI System or equivalent for 4.5 - 18 hours. The minimum inhibitory concentration (MIC) for the test organism is determined by the lowest antimicrobial concentration showing inhibition of growth.
Here's an analysis of the provided text regarding the acceptance criteria and study for the MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panels with Imipenem:
1. Table of Acceptance Criteria and Reported Device Performance
| Metric | Acceptance Criteria (Implicit from FDA Guidance) | Reported Device Performance |
|---|---|---|
| Essential Agreement | > 90% (based on typical FDA guidance) | > 96% |
| Reproducibility | Acceptable (implied by "acceptable reproducibility and precision") | Acceptable |
| Quality Control Testing | Acceptable (implied by "acceptable results") | Acceptable |
Note: The document explicitly states "overall Essential Agreement of greater than 96% for Imipenem when compared with the frozen Reference panel." While the specific numerical acceptance criteria (e.g., >90%) aren't explicitly stated in the provided text for all metrics, the "Guidance on Review Criteria for Assessment of Antimicrobial Susceptibility Devices" dated March 8, 2000, which is referenced, would contain these. For Essential Agreement, >90% is a common benchmark for such devices.
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: Not explicitly stated. The document mentions "external evaluation was conducted with fresh and stock Efficacy isolates and stock Challenge strains." However, the exact number of isolates/strains used is not provided.
- Data Provenance: The document does not specify the country of origin. It indicates the data was collected through "external evaluation," implying it was not solely internal to the manufacturer. It also mentions "fresh and stock Efficacy isolates and stock Challenge strains," suggesting a mix of real-world isolates and controlled laboratory strains. The term "external evaluation" points to it being prospective data collection for the purpose of the submission.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts
This information is not provided in the document. The ground truth was established by an "NCCLS frozen Reference panel," which is a standardized method, not directly a human expert consensus.
4. Adjudication Method for the Test Set
This information is not applicable in the traditional sense, as the ground truth was an "NCCLS frozen Reference panel," which serves as the gold standard for comparison, rather than requiring human adjudication of discordant results.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study was not done. This study focused on the performance of the device itself against a reference method, not on human reader improvement with or without AI assistance. The device is an automated system for reading susceptibility panels.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance study was done. The goal was to demonstrate that the MicroScan® rapID/S plus™ Gram-Negative MIC/Combo Panel, read on the WalkAway® S7 System, could accurately determine antimicrobial susceptibility. This is an "algorithm only" performance because the device itself automates the reading and interpretation of the MIC panels.
7. Type of Ground Truth Used
The type of ground truth used was an "NCCLS frozen Reference Panel." NCCLS (now CLSI - Clinical and Laboratory Standards Institute) reference panels are standardized methods considered the gold standard for antimicrobial susceptibility testing.
8. Sample Size for the Training Set
This information is not provided in the document. The document describes the evaluation of the device, not the development or training of any underlying algorithms. Since the device is a microdilution system read by an instrument, it doesn't typically involve a "training set" in the machine learning sense for its core function, though instrument calibrations would require data.
9. How the Ground Truth for the Training Set Was Established
This information is not provided as a "training set" in the AI/ML context is not mentioned. If referring to the development/calibration of the overall system, it would likely involve similar methods as the test set: comparison to NCCLS/CLSI reference methods and established microbiological standards.
§ 866.1645 Fully automated short-term incubation cycle antimicrobial susceptibility system.
(a)
Identification. A fully automated short-term incubation cycle antimicrobial susceptibility system is a device that incorporates concentrations of antimicrobial agents into a system for the purpose of determining in vitro susceptibility of bacterial pathogens isolated from clinical specimens. Test results obtained from short-term (less than 16 hours) incubation are used to determine the antimicrobial agent of choice to treat bacterial diseases.(b)
Classification. Class II (special controls). The special control for this device is FDA's guidance document entitled “Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA.”