(68 days)
The MicroScan® Dried 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. 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 the addition of the antimicrobial amoxicillin/ K. clavulanate at concentrations of 0.25/0.12 to 128/64 mcg/ml to the test panel.
The gram-negative organisms which may be used for amoxicillin/K. clavulanate susceptibility testing in this panel are:
Enterobacter species
Escherichia coli
Klebsiella species
Proteus mirabilis
MicroScan® Dried Gram-Negative MIC/Combo Panels are designed for use in determining quantitative MICIOSCalle Direct Stan-Negative MICH of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic Gram-Negative bacilli.
The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test that have The allumic louial stiscopulary tosts are minicationic agents are diluted in broth to concentrations bridging the range of clinical interest. Parlous are relydrated with water after inoculation with a standardized suspension of the organism. After incubation in a non-CO- incubator for 16-20 hours, the minimum inizitory suspension of the organism. There measurement is read by determining the lowest antimicrobial concentration showing inhibition of growth.
Here's a breakdown of the acceptance criteria and the study details for the MicroScan® Dried Gram-Negative MIC/Combo Panels with Amoxicillin/K. Clavulanate, based on the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria (Predicate Equivalent) | Reported Device Performance |
|---|---|
| Substantially equivalent performance compared with an NCCLS frozen Reference Panel, as defined in the FDA document "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA" (specific metric not explicitly stated, but implies high agreement). | The Dried Gram-Negative Panel achieved an overall Essential Agreement of >99% for amoxicillin/K. clavulanate when compared with the frozen Reference panel. |
| Acceptable reproducibility and precision for amoxicillin/K. clavulanate, regardless of inoculum method (Turbidity and Prompt) or instrument (autoSCAN-4 and WalkAway®). | Inoculum and instrument reproducibility testing demonstrated acceptable reproducibility and precision with amoxicillin/K. clavulanate, regardless of which inoculum method (i.e., Turbidity and Prompt), or instrument (autoSCAN-4 and WalkAway®) was used. (Specific metrics for "acceptable" are not provided in the summary but were evidently met). |
| Acceptable Quality Control (QC) results for amoxicillin/K. clavulanate. | Quality Control testing demonstrated acceptable results for amoxicillin/K. clavulanate. (Specific metrics for "acceptable" are not provided). |
Study Details
This submission describes a comparative study to demonstrate substantial equivalence to a predicate device (NCCLS frozen Reference Panel) for the addition of a new antimicrobial, amoxicillin/K. clavulanate, to an existing panel.
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Sample Size Used for the Test Set and Data Provenance:
- Sample Size: Not explicitly stated as a numerical value (i.e., number of isolates or tests). The study used "fresh and stock Efficacy isolates and stock Challenge strains."
- Data Provenance: Not explicitly stated (e.g., country of origin). The data is described as from "external evaluation," implying it was conducted outside of Dade MicroScan Inc.'s immediate environment, likely at clinical or reference laboratories. The study is retrospective, as it uses "stock Efficacy isolates and stock Challenge strains" in addition to fresh isolates.
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Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified. However, the ground truth is established by the NCCLS frozen Reference panel, which inherently suggests expert consensus in its development and validation, as NCCLS (now CLSI) is a recognized standard-setting body in clinical laboratory testing.
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Adjudication Method for the Test Set:
- Adjudication Method: Not explicitly described in terms like "2+1" or "3+1." The evaluation compares the device's performance directly against the "NCCLS frozen Reference panel." This implies the reference panel is the ground truth against which the device results are compared, rather than a separate adjudication process among experts for each test case.
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If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No, an MRMC comparative effectiveness study was not done. This study focuses on the performance of a device for antimicrobial susceptibility testing, not on human reader performance or AI assistance in reading, and thus, an effect size of human improvement with AI is not applicable here. The device is read either visually or with MicroScan instrumentation.
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If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, a standalone performance evaluation was implicitly done, and is the primary focus. The device (MicroScan® Dried Gram-Negative MIC/Combo Panel) itself is being evaluated for its ability to determine MIC values compared to a reference method. While human readers can interpret the results visually, the "device performance" itself refers to the panel's accuracy in producing the MIC, independent of the human interpretation stage for the Essential Agreement metric. The mention of "MicroScan instrumentation" also points to automated reading capabilities, which would be standalone.
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The Type of Ground Truth Used:
- The ground truth used is the NCCLS frozen Reference Panel. This represents a highly standardized and validated method that serves as a gold standard (or a very strong reference standard) for antimicrobial susceptibility testing, implicitly based on established microbiological principles and expert consensus within the NCCLS (now CLSI) framework.
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The Sample Size for the Training Set:
- Not applicable / Not provided. The document describes a performance evaluation (validation/test set) against a reference standard. It does not describe a machine learning algorithm that would require a distinct "training set" in the conventional sense. The "fresh and stock Efficacy isolates and stock Challenge strains" constitute the test set for performance comparison.
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How the Ground Truth for the Training Set was Established:
- Not applicable. As no distinct training set for an AI/ML model is described, there's no ground truth establishment for such a set. The performance is assessed against the NCCLS frozen Reference Panel as the ground truth.
§ 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).