(54 days)
The MicroScan® Synergies plus™ Gram-Positive 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-positive staphylococci and enterococci. After inoculation, panels are incubated for 4.5 - 18 hours at 35℃ +/- 1℃, in a WalkAway® SZ, or equivalent, and read by the MicroScan® Instrumentation. Additionally, the panels may be incubated in a non-CO2 incubator and the Antimicrobial Susceptibility Testing (AST) portions can be read visually, according to the Package Insert.
This particular submission is for the addition of the antimicrobial Levofloxacin, at concentrations of 0.03 to 16 ug/ml, to the test panel.
The gram-positive organisms which may be used for Levofloxacin susceptibility testing in this panel are:
Enterococcus faecalis Staphylococcus aureus (methicillin-susceptible strains) Staphylococcus epidermidis (methicillin-susceptible strains) Staphylococcus saprophyticus Staphylococcus haemolyticus
MicroScan® Synergies plus™ Gram-Positive MIC/Combo Panels, utilizing both the MicroScan® Rapid MIC and Synergies plus™ Gram-Positive Antimicrobial Susceptibility Testing (AST) technologies, are for use in determining quantitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic gram-positive staphylococci and enterococci.
The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test that have been dried in water and dehydrated. Various antimicrobial agents are diluted in water, buffer, or minute amounts of clinical interest. Panels are rehydrated with Synergies plus™ Pos Broth, after inoculation with a standardized suspension of the organism. After incubation, for 4.5 - 18 hours, the minimum inhibitory concentration in the wells is determined by determining the lowest antimicrobial concentration showing inhibition of growth.
Here's a summary of the acceptance criteria and the study details for the MicroScan® Synergies plus™ Gram-Positive MIC/Combo Panels with Levofloxacin, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
| Metric | Acceptance Criteria | Reported Device Performance (Levofloxacin) |
|---|---|---|
| Essential Agreement | >95% (FDA Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Class II Special Controls Guidance Document, Jan 5, 2003) | >98% |
| Reproducibility | Acceptable (Specific quantitative criteria not provided in summary, but assumed to meet standard for "acceptable reproducibility and precision") | Acceptable |
| Quality Control | Acceptable | Acceptable |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Description: The external evaluation was conducted with fresh and stock Efficacy isolates and stock Challenge strains.
- Sample Size: The exact number of isolates/strains used for the test set is not explicitly stated in the provided summary. However, it's mentioned that the study was designed to confirm performance by comparing it with a frozen Reference panel.
- Data Provenance: The document does not specify the country of origin of the data. It is a prospective evaluation, as new antimicrobial (Levofloxacin) data was generated for the panel.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number or qualifications of experts used to establish the ground truth. The comparison was made against a "frozen Reference panel," which implies a standardized method of determining ground truth.
4. Adjudication Method for the Test Set
The document does not explicitly state an adjudication method. The comparison was against a "frozen Reference panel," indicating a direct comparison rather than a human consensus-based adjudication process for each individual test result.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No MRMC comparative effectiveness study is mentioned. This device is an automated antimicrobial susceptibility testing panel, and the study focuses on its standalone analytical performance against a reference method, not on human reader performance or improvement with 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 entire evaluation described in the summary is focused on the performance of the MicroScan® Synergies plus™ Gram-Positive MIC/Combo Panel with Levofloxacin, comparing its results to a standardized reference method. The device automates the determination of MICs.
7. The Type of Ground Truth Used
The ground truth used was established by a "frozen Reference panel." This implies a reference standard or method for determining antimicrobial susceptibility, likely involving a recognized laborious and precise method that serves as the gold standard for comparison (e.g., agar dilution or broth microdilution performed under highly controlled conditions by a reputable laboratory).
8. The Sample Size for the Training Set
The document does not specify a training set sample size. This type of device relies on established principles of broth microdilution and the "new antimicrobial" (Levofloxacin) is being added to an existing, validated panel. Therefore, a separate "training set" in the context of machine learning might not be directly applicable, or if internal development involved a training set, it is not detailed in this 510(k) summary.
9. How the Ground Truth for the Training Set Was Established
Since a training set is not explicitly mentioned or detailed, the method for establishing its ground truth is not provided.
§ 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.”