(77 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 fermenters. After inoculation, panels are read on the WalkAway® SI System or equivalent (upgraded WalkAway® 40 or WalkAway® 96) according to the Package Insert.
This particular submission is for the antimicrobial Ampicillin/Sulbactam on the Synergies Gram-Negative MIC/Combo Panels. plus
The Gram-Negative organisms which may be used for Ampicillin/Sulbactam susceptibility testing in this panel are:
Escherichia coli Klebsiella spo Proteus mirabilis Proteus vulgaris Providencia rettgeri Providencia stuartii
The MicroScan® Synergies plus™ Gram-Negative with Ampicillin/Sulbactam is not intended for use with:
Acinetobacter calcoaceticus Citrobacter spp. Enterobacter spp. Morganella morganii Salmonella spp. Shigella spp.
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™ Gram-Negative MIC/Combo Panels are read on the WalkAway® S/ 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 and rehydrated with a standardized suspension of the organism and incubated at 35°C in the WalkAway® S/ System or equivalent for 4.5 - 18 hours. The minimum inhibitory concentration (MC) for the test organism is determined by the lowest antimicrobial concentration showing inhibition of growth.
Here's a breakdown of the acceptance criteria and study information for the MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panels with Ampicillin/Sulbactam, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Essential Agreement (EA) | 92.5% for Ampicillin/Sulbactam |
| Reproducibility | Acceptable reproducibility |
| Precision | Acceptable precision |
| Quality Control (QC) | Acceptable results |
Note: The document refers to the "FDA DRAFT document 'Guidance on Review Criteria for Assessment of Antimicrobial Susceptibility Devices', dated March 8, 2000" for the definition of "substantially equivalent performance" and implies these criteria are derived from that guidance. Specific numerical acceptance thresholds for reproducibility, precision, and QC are not explicitly stated in the provided text, only that the performance was "acceptable."
2. Sample Size Used for the Test Set and Data Provenance
The document mentions "external evaluation was conducted with fresh and stock Efficacy isolates and stock Challenge strains." However, the exact sample size (number of isolates/strains) used for the test set is not specified.
The provenance of the data is not explicitly stated regarding country of origin. The study appears to be a prospective evaluation in the sense that fresh and stock isolates were evaluated against a reference method.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document states that the performance was compared "with an NCCLS frozen Reference Panel." The "Expected Results" for challenge strains were "determined prior to the evaluation." This implies that the ground truth was established by a recognized reference method (NCCLS frozen panel) and potentially by expert consensus for the challenge strains.
The number and qualifications of experts involved in establishing the ground truth are not specified in this document.
4. Adjudication Method for the Test Set
The document does not explicitly state an adjudication method (e.g., 2+1, 3+1). The comparison was made against an "NCCLS frozen Reference Panel" and "Expected Results," suggesting a direct comparison rather than a multi-reader adjudication process for discrepancies.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a multi-reader multi-case (MRMC) comparative effectiveness study focusing on human readers improving with AI vs. without AI assistance was not mentioned or performed. This device is an automated antimicrobial susceptibility testing system, not an AI-assisted diagnostic imaging tool that typically involves human interpretation.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance evaluation was conducted. The study assessed the performance of the "MicroScan® rapID/S plus™ Gram-Negative MIC/Combo panel" (the device under review, later referred to as Synergies plus™) against a reference method. The device is described as an automated system that reads panels on the WalkAway® S/ System or equivalent. This independent evaluation of the device's accuracy represents a standalone performance assessment.
7. The Type of Ground Truth Used
The ground truth was established using:
- NCCLS frozen Reference Panel: This is a recognized standard for antimicrobial susceptibility testing, representing a highly reliable reference method.
- "Expected Results" for Challenge Strains: These were determined prior to the evaluation, likely through established laboratory methods and expert consensus or confirmation of known resistance/susceptibility patterns.
8. The Sample Size for the Training Set
The document does not provide information about a training set size. Antimicrobial susceptibility testing devices like this typically use established methods and reference panels for validation rather than machine learning models that require a distinct training set. The "fresh and stock Efficacy isolates and stock Challenge strains" were used for the external evaluation/test set.
9. How the Ground Truth for the Training Set Was Established
As no training set is explicitly mentioned or relevant to this type of device validation based on traditional microbiology methods, this information is not applicable and not provided in the document.
§ 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.”