(65 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 Levofloxacin at concentrations of 0.12 to 16 mcg/ml to the test panel. The organisms which may be used for Levofloxacin susceptibility testing in this panel are; Streptococcus pneumoniae (including penicillin-resistant strains), Streptococcus pyogenes, Streptococcus (Group C/F), Streptococcus (Group G), Streptococcus agalactiae, 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 provided document describes the acceptance criteria and the study that proves the MicroScan® MICroSTREP plus™ Panel with Levofloxacin meets those criteria.
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (for Levofloxacin) | Reported Device Performance (Levofloxacin) |
|---|---|
| Overall Essential Agreement with NCCLS frozen Reference Panel | >99% Essential Agreement |
| Acceptable Reproducibility and Precision | Demonstrated acceptable reproducibility and precision |
| Acceptable Quality Control results | Demonstrated acceptable results |
2. Sample Size Used for the Test Set and Data Provenance:
The document states that the external evaluation was conducted with:
- "fresh and stock Efficacy isolates"
- "stock Challenge strains"
The exact sample size (number of isolates/strains) is not explicitly stated in the provided text.
The data provenance is described as "external evaluation," but the country of origin is not specified. It is a prospective study as it involves testing the new device.
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 of experts used or their qualifications for establishing the ground truth. It refers to comparing the device's performance with an "NCCLS frozen Reference Panel" and "manual reading" by observing the lowest antimicrobial concentration.
4. Adjudication Method for the Test Set:
The document does not explicitly describe an adjudication method. The comparison is made against an "NCCLS frozen Reference Panel," which implicitly suggests the reference panel values serve as the ground truth. The process is described as "manual reading by observing the lowest antimicrobial concentration showing inhibition of growth" for the test organism in both the reference and the new device.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study assesses the performance of a diagnostic device in comparison to a reference standard, not the improvement of human readers with AI assistance. The study focuses on the "MicroScan® MICroSTREP plus™ Panel," which is a laboratory test device, not an AI-assisted diagnostic tool for human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
The device described, the MicroScan® MICroSTREP plus™ Panel, is a laboratory test panel for antimicrobial susceptibility testing. Its performance is evaluated directly. The reading process is described as "manually read by observing the lowest antimicrobial concentration showing inhibition of growth." Therefore, the study presented here is the standalone performance of the test panel as interpreted manually, without any AI or algorithm that would operate independently.
7. The Type of Ground Truth Used:
The ground truth used for comparison was an NCCLS frozen Reference Panel. This serves as a standardized and accepted reference method for antimicrobial susceptibility testing.
8. The Sample Size for the Training Set:
The document does not describe a training set as this is a traditional laboratory diagnostic device, not an AI/machine learning model that requires explicit training data. The study focuses on the performance of the developed panel.
9. How the Ground Truth for the Training Set Was Established:
As there is no described training set for an AI/machine learning model, 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).