(57 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 Trimethoprim/Sulfamethoxazole at concentrations of 0.06/1.15 to 8/152 mcg/ml to the test panel. The organisms which may be used for Trimethoprim/ Sulfamethoxazole susceptibility testing in this panel are: Streptococcus pneumoniae.
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 (MC) for the test organism is manually read by observing the lowest antimicrobial concentration showing inhibition of growth.
Here's an analysis of the provided 510(k) summary, detailing the acceptance criteria and study information:
Device Performance and Acceptance Criteria
| Acceptance Criterion | Reported Device Performance (MICroSTREP plus™ Panel with Trimethoprim/Sulfamethoxazole) |
|---|---|
| Essential Agreement | 100% Essential Agreement with NCCLS frozen Reference Panel |
| Reproducibility | Acceptable reproducibility and precision |
| Quality Control | Acceptable results |
Note: The specific numerical thresholds for "acceptable" reproducibility and quality control are not provided in the summary, but it's stated that the device met these criteria. Essential Agreement is a common metric for AST devices, comparing the MIC results of the test device to a reference method.
Study Information
1. Sample Size Used for the Test Set and Data Provenance:
* Sample Size: Not explicitly stated as a numerical count of isolates. The document mentions "fresh and stock Efficacy isolates and stock Challenge strains." However, further specifics on the quantity of each type are not provided.
* Data Provenance: The study was an "external evaluation," implying data was collected independently from the device manufacturer. No country of origin is specified, but the use of "NCCLS frozen Reference Panel" suggests a standard recognized in the US (National Committee for Clinical Laboratory Standards, now CLSI). The isolates were a mix of "fresh and stock" and "challenge strains," indicating both recently isolated clinical strains and well-characterized laboratory strains. The study design is implied to be prospective for collecting "fresh... Efficacy isolates" and potentially retrospective for "stock Efficacy isolates and stock Challenge strains" sourced from a frozen bank.
2. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications:
* Not applicable. The ground truth was established using an NCCLS frozen Reference Panel, not through human experts interpreting results from the device under evaluation.
3. Adjudication Method for the Test Set:
* Not applicable. The comparison was to a reference standard with established results (the NCCLS frozen Reference Panel), not to human interpretations requiring adjudication.
4. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
* No, an MRMC study was not done. This study solely evaluated the performance of the device against a reference standard, not the improvement of human readers with AI assistance. The device is a diagnostic panel for susceptibility testing, not an AI-assisted interpretation tool for human readers.
5. Standalone Performance (Algorithm Only Without Human-in-the-Loop Performance):
* Yes, this was a standalone performance study for the device. The device (MicroScan® MICroSTREP plus™ Panel) was evaluated by comparing its visually-read results to an NCCLS frozen Reference Panel. While human observation is involved in reading the MIC, the evaluation focuses on the panel's ability to produce accurate results independently, not on aiding human interpretation with an AI algorithm.
6. Type of Ground Truth Used:
* The ground truth was established by an NCCLS frozen Reference Panel. This panel would have pre-determined and validated Minimum Inhibitory Concentration (MIC) values for the tested antimicrobial agents against specific bacterial strains. This is a highly standardized and accepted method for determining ground truth in antimicrobial susceptibility testing.
7. Sample Size for the Training Set:
* Not applicable. The provided document details a 510(k) submission for a diagnostic panel, which is a physical consumable for laboratory testing. It is not an AI/ML algorithm that requires a training set.
8. How the Ground Truth for the Training Set Was Established:
* Not applicable, as there is no training set for this device.
§ 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).