(63 days)
To determine bacterial antimicrobial agent susceptibility. The MicroScan® MICroSTREP plus™ Panel is used to determine quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of aerobic streptococci, including Streptococcus pneumoniae. After inoculation, panels are incubated for 20-24 hours at 35°C +/- 1°C in a non-CO2 incubator, and read visually according to the Package Insert. This particular submission is for the addition of the antimicrobial Clarithromycin at concentrations of 0.015 to 2 mcg/ml to the test panel. The organisms which may be used for Clarithromycin susceptibility testing in this panel are: Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Streptococci (Groups C, F, G), viridans group streptococci.
The MicroScan® MICroSTREP plus™ Panel is used to determine quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of aerobic streptococci, including Streptococcus pneumoniae. After inoculation, panels are incubated for 20-24 hours at 35°C +/- 1°C in a non-CO2 incubator, and read visually according to the Package Insert. The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test. Various antimicrobial agents are diluted in water, buffer or minute concentrations of broth to concentrations bridging the range of clinical interest. Panels are rehydrated with 115 ul Mueller-Hinton broth supplemented with 2-5% lysed horse blood (LHB) and buffered with 50 mM HEPES, after inoculation of the broth with a standardized suspension of the organism in saline. After incubation in a non-CO2 incubator for 20-24 hours, the minimum inhibitory concentration (MIC) for the test organism is manually read by observing the lowest antimicrobial concentration showing inhibition of growth.
The MicroScan® MICroSTREP plus™ Panel is intended to determine bacterial susceptibility to Clarithromycin for aerobic streptococci, including Streptococcus pneumoniae. The study compared the performance of the MicroScan® MICroSTREP plus™ Panel with an NCCLS frozen Reference Panel.
Here's a breakdown of the requested information:
1. Table of acceptance criteria and the reported device performance
| Acceptance Criteria | Reported Device Performance (Clarithromycin) |
|---|---|
| Overall Essential Agreement (compared to NCCLS frozen Reference panel) | 98.6% |
| Reproducibility | Acceptable |
| Precision | Acceptable |
| Quality Control | Acceptable |
2. Sample size used for the test set and the data provenance
- Sample Size: Not explicitly stated as a numerical value, but the study used "fresh and stock Efficacy isolates and stock Challenge strains" for external evaluation.
- Data Provenance: The document does not specify the country of origin of the data. The study was a comparison against an NCCLS frozen Reference Panel, which typically implies standardized, controlled conditions. It's prospective in the sense that new tests were run using these isolates, but the "stock isolates" could have a retrospective element in their origin.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
This information is not provided in the document. The ground truth was established by an "NCCLS frozen Reference Panel," which implicitly suggests a recognized standard method, but details about experts or their qualifications for establishing this reference are not given.
4. Adjudication method for the test set
This information is not explicitly stated. The comparison was made against an "NCCLS frozen Reference Panel," suggesting a direct comparison to a gold standard rather than expert adjudication of discrepancies.
5. 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
A multi-reader multi-case (MRMC) comparative effectiveness study was not done. This device is an automated in vitro diagnostic susceptibility panel, not an AI-assisted human reading system. There is no human-in-the-loop component described in the reading process that would involve different readers or AI assistance. The panels are "read visually according to the Package Insert" after incubation.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
Yes, essentially a standalone performance study was done for the device. The device's performance (MICroSTREP plus™ Panel) was directly compared against a reference standard (NCCLS frozen Reference panel), without human intervention in interpreting the results from either system, beyond a visual read of the device's output. The "algorithm" in this context refers to the chemical and biological process within the panel that determines susceptibility, and its output is then visually interpreted.
7. The type of ground truth used
The ground truth used was based on an NCCLS frozen Reference Panel. This represents a recognized gold standard method for antimicrobial susceptibility testing.
8. The sample size for the training set
The document does not mention a training set. The descriptions relate to evaluation/test sets for demonstrating performance and equivalence. This is typical for in vitro diagnostic devices based on established biological/chemical principles, rather than machine learning models that require explicit training.
9. How the ground truth for the training set was established
As no training set is mentioned, this question is not applicable.
§ 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).