(56 days)
The MicroScan® Dried 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 Gram-Positive cocci. After inoculation, panels are incubated for 16 - 20 hours at 35°C +/- 1°C in a non-CO2 incubator, and read either visually or with MicroScan instrumentation, according to the Package Insert.
This particular submission is for a revised QC range of ≥ 0.25 mcg/ml for S. aureus ATCC 29213 with Penicillin.
The Gram-Positive organisms which may be used for Penicillin susceptibility testing in this panel are:
Staphylococci (except penicillinase-producing strains)
Streptococci (group A)
The MicroScan® Dried Gram-Positive MIC/Combo Panels with Penicillin are not intended for use with Streptococcus pneumoniae and viridans streptococci.
MicroScan® Dried Gram-Positive MIC/Combo Panels are designed for use in determining quantitative and acceptibility of colonies grown on solid media of rapidly growing aerobic and facultative Gram-Positive cocci.
The antimicrobial susceptibility tests are miniaturizations of the broth dilution usceptibility tost that have been diluted in broth and deliyated. Vanous anninorotat agents are diluted in broth to concentrations bridging the range of chilical interest: Tancis are rears are 16-20 hours, the minimum suspension of the organism. After incubation in a non-CO2 incubation the lowest antimi suspension of the organism. After incuration in a non- Organism is read by determining 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® Dried Gram-Positive MIC/Combo Panels:
Note: The provided document is a 510(k) summary and FDA clearance letter, which means it describes the device and its intended use, but does not contain the full study report with detailed acceptance criteria, sample sizes, and ground truth information. The information below is extracted from what is available in the provided text.
Description of the Acceptance Criteria and the Study
The submission focuses specifically on a revised Quality Control (QC) range for Penicillin (≥0.25 mcg/ml) for S. aureus ATCC 29213 when used with the MicroScan® Dried Gram-Positive MIC/Combo Panels.
The study aimed to demonstrate that the proposed MicroScan® Dried Gram-Positive MIC/Combo Panel with the revised QC range for Penicillin is substantially equivalent in performance to an NCCLS (National Committee for Clinical Laboratory Standards, now CLSI) frozen Reference.
The general principle of the device is to determine antimicrobial agent susceptibility by miniaturized broth dilution. Antimicrobial agents are diluted in broth, and a suspension of the organism is added. After incubation, the lowest antimicrobial concentration showing inhibition of growth (Minimum Inhibitory Concentration - MIC) is determined.
1. Table of Acceptance Criteria and Reported Device Performance
Based on the provided text, the specific acceptance criteria for the S. aureus ATCC 29213 with Penicillin QC range are mentioned as:
| Acceptance Criterion | Reported Device Performance |
|---|---|
| Revised QC range for Penicillin with S. aureus ATCC 29213 | ≥ 0.25 mcg/ml |
| Performance relative to NCCLS frozen Reference | The proposed MicroScan® Dried Gram-Positive MIC/Combo Panel "demonstrates equivalent performance when compared with an NCCLS frozen Reference." |
Specific quantitative acceptance metrics (e.g., essential agreement, category agreement percentages) are not provided in the summary. The statement "demonstrates equivalent performance" is a general claim based on the FDA's guidance document for such devices.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: Not specified in the provided document.
- Data Provenance: Not specified (e.g., country of origin, retrospective/prospective). The study refers to "assessments data in support of a revised Quality Control (QC) range," implying data collected for this purpose.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications of Experts
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified. (This type of study typically involves laboratory personnel, but their qualifications are not detailed here).
4. Adjudication Method for the Test Set
- Adjudication Method: Not specified. For QC range verification, it's typically a direct comparison, rather than an adjudication process between multiple human readers evaluating a result.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- Was an MRMC study done? No.
- Effect size of human reader improvement: Not applicable, as this is a device for automated/semi-automated susceptibility testing, not a diagnostic imaging aid for human readers.
6. Standalone (Algorithm Only) Performance Study
- Was a standalone study done? Yes, inherently. The "demonstrates equivalent performance" claim is for the device (algorithm/system) itself in comparison to a reference standard, without direct human intervention in the MIC determination process after inoculation. The panels can be read visually or with MicroScan instrumentation, but the comparison is directly between the MicroScan panel's result and the reference method.
7. Type of Ground Truth Used
- Type of Ground Truth: The ground truth was established using an NCCLS frozen Reference method. The document refers to the "FDA DRAFT document 'Guidance on Review Criteria for Assessments data...'" for Antimicrobial Susceptibility Devices, indicating that this reference method is a recognized standard for establishing ground truth in this context.
8. Sample Size for the Training Set
- Sample Size for Training Set: Not specified. The document focuses on demonstrating the performance of the pre-developed device with a specific QC range, rather than describing the development/training of the device itself.
9. How Ground Truth for the Training Set Was Established
- How Ground Truth Was Established (Training Set): Not applicable/not specified. The document describes a performance evaluation of an existing product with a revised QC range, not the initial development or training phase where a "training set ground truth" would typically be detailed. The device itself (broth dilution method) is a well-established technology; the submission is for a specific product and a revised QC parameter within it.
§ 866.1640 Antimicrobial susceptibility test powder.
(a)
Identification. An antimicrobial susceptibility test powder is a device that consists of an antimicrobial drug powder packaged in vials in specified amounts and intended for use in clinical laboratories for determining in vitro susceptibility of bacterial pathogens to these therapeutic agents. Test results are used to determine the antimicrobial agent of choice in the treatment of bacterial diseases.(b)
Classification. Class II (performance standards).