(99 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 on the Synergies plus" Gram-Negative MIC/Combo Panels.
The Gram-Negative organisms which may be used for Ampicillin susceptibility testing in this panel are:
Escherichia coli Salmonella spp.
The MicroScan® Synergies plus™ Gram-Negative with Ampicillin is not intended for use with:
Citrobacter spp. Enterobacter spp. Klebsiella spp. Providencia spp. Proteus mirabilis Proteus vulgaris 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 SI 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® SV 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.
The document describes the performance of the MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panels with Ampicillin for determining antimicrobial susceptibility.
1. Acceptance Criteria and Reported Device Performance
The study compares the performance of the MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panel with Ampicillin against an NCCLS frozen Reference Panel.
| Acceptance Criteria (Stated Goal in "Guidance on Review Criteria for Assessment of Antimicrobial Susceptibility Devices") | Reported Device Performance (MicroScan® Synergies plus™ Gram-Negative with Ampicillin) |
|---|---|
| Overall Essential Agreement (EA) with reference method | 97.6% EA |
| Reproducibility and Precision | Acceptable for Turbidity inoculum prep method and WalkAway SI System |
| Quality Control results | Acceptable for Ampicillin |
Note: The specific numeric acceptance criteria for Essential Agreement, Reproducibility, and Quality Control are not explicitly stated in the provided text but are implied to have been met by the device's reported performance.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: The document mentions that the external evaluation was conducted with "fresh and stock Efficacy isolates and stock Challenge strains." However, the exact number of isolates or strains used for the test set is not specified in the provided text.
- Data Provenance: The data provenance is not explicitly stated in terms of country of origin. The evaluation was an "external evaluation," implying it was conducted outside the manufacturer's internal testing. It appears to be a prospective evaluation comparing the new device against a reference method.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
This information is not provided in the document. The ground truth was established by an "NCCLS frozen Reference Panel" and "Expected Results determined prior to the evaluation" for challenge strains, but details on human experts involved or their qualifications are absent.
4. Adjudication Method for the Test Set
The adjudication method is not explicitly stated. The comparison was made against an "NCCLS frozen Reference Panel" and "Expected Results" for challenge strains. It's likely that the reference panel itself serves as the 'ground truth' rather than a human adjudication process in the traditional sense for image interpretation.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study is focused on the standalone performance of the automated antimicrobial susceptibility testing device compared to a reference method, not on human reader performance with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was Done
Yes, a standalone performance study was done. The report describes the evaluation of the MicroScan® Synergies plus™ Gram-Negative MIC/Combo Panel with Ampicillin (an automated device that determines MIC) against an "NCCLS frozen Reference Panel." This evaluation assesses the device's ability to accurately determine antimicrobial susceptibility concentrations without human intervention in the interpretation of the results.
7. The Type of Ground Truth Used
The ground truth used was primarily an NCCLS frozen Reference Panel. For challenge strains, "Expected Results" determined prior to the evaluation were used. These methods are considered established laboratory reference standards for antimicrobial susceptibility testing.
8. The Sample Size for the Training Set
The document does not provide any information about a separate training set or its sample size. This type of device evaluation typically focuses on validation against a reference method rather than a machine learning training paradigm.
9. How the Ground Truth for the Training Set Was Established
As no training set is mentioned, this information is not available.
§ 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.”