(52 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 Cefepime at concentrations of 0.015 to 8 mcg/ml to the test panel. The organisms which may be used for Cefepime susceptibility testing in this panel are: Streptococcus pneumoniae, Streptococcus pyogenes (Lancefield's Group A streptococci), Streptococcus agalactiae (Lancefield's Group B streptococci), 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 (MC) for the test organism is manually read by observing the lowest antimicrobial concentration showing inhibition of growth.
Here's a breakdown of the acceptance criteria and study information for the MicroScan® MICroSTREP plus™ Panel with Cefepime, based on the provided text:
Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Overall Essential Agreement | 96.3% for Cefepime when compared with the frozen Reference panel |
| Reproducibility | Acceptable reproducibility and precision with Cefepime |
| Quality Control | Acceptable results for Cefepime |
Study Details
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Sample size used for the test set and the data provenance:
- Test Set Size: Not explicitly stated as a number, but the evaluation was conducted with "fresh and stock Efficacy isolates and stock Challenge strains."
- Data Provenance: The external evaluation was conducted to compare performance with an "NCCLS frozen Reference Panel." The origin of the actual bacterial isolates (countries, etc.) is not specified, nor is whether the data was retrospective or prospective. It is implied to be prospective for the purpose of the study.
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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 comparing the device performance to an "NCCLS frozen Reference Panel," which acts as the gold standard, but details on how that reference panel's "ground truth" was initially established (e.g., how many experts, their qualifications, etc.) are absent.
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Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- This information is not provided in the document. The comparison was made directly against the NCCLS frozen Reference Panel, suggesting no explicit human adjudication process for the test results themselves beyond the visual reading specified for the device.
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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. This is not an AI device. It's an in vitro diagnostic device (microdilution panel) for antimicrobial susceptibility testing. The readings are described as "manually read by observing." Therefore, an MRMC study related to AI assistance is not applicable.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- No. The device requires human interaction ("manually read by observing the lowest antimicrobial concentration showing inhibition of growth"). It is not a standalone algorithm.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc):
- The ground truth was established by an NCCLS frozen Reference Panel. This reference panel serves as the accepted standard for determining minimum inhibitory concentrations (MICs). This is a form of reference standard comparative data, where the new device's results are compared to a well-established and validated method.
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The sample size for the training set:
- The document primarily describes an external evaluation or test set that compared the device to a reference panel. It does not explicitly mention a separate training set or its size. Microdilution panels like this are generally developed based on established microbiological principles rather than machine learning training sets.
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How the ground truth for the training set was established:
- Since a distinct "training set" in the context of machine learning is not described for this device, information on how its ground truth was established is not applicable/provided. The development of these types of panels typically relies on extensive historical microbiological data and standardized methodologies to determine appropriate antimicrobial concentrations and efficacy.
§ 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).