(70 days)
For in vitro diagnostic use:
System U3™ is a qualitative technique for antimicrobial susceptibility testing of nonfastidious Gram negative and Gram positive aerobic bacteria, such as Enterobacteriaceae, Pseudomonas, Staphylococcus and Enterococcus species. The system comprises an antibiotic gradient with MIC break-point concentrations and is used to determine the susceptibility categories of microorganisms to different antimicrobial agents, as tested on agar media using overnight incubation.
This 510(k) application is for System U3/Trimethoprim/sulfamethoxazole susceptibility testing based on the MIC breakpoints of Susceptible ≤ 2 µg/ml and Resistant ≥ 4 µg/ml for use with non-fastidious Gram negative and Gram positive aerobic bacteria.
The system comprises an antibiotic gradient with MIC break-point concentrations and is used to determine the susceptibility categories of microorganisms to different antimicrobial agents, as tested on agar media using overnight incubation.
This document is a 510(k) premarket notification decision letter from the FDA for the "System U3™ for Trimethoprim/sulfamethoxazole." It primarily focuses on the regulatory approval and substantial equivalence to a predicate device, rather than detailed performance and study information of the device itself.
Therefore, much of the requested information regarding acceptance criteria, study details, sample sizes, expert qualifications, and ground truth establishment is not available in this document. This letter confirms approval and outlines regulatory responsibilities but does not contain the technical study data.
However, I can extract the following:
1. A table of acceptance criteria and the reported device performance:
Based on the "Indications For Use" section, the acceptance criteria relates to the determination of susceptibility categories using specific MIC breakpoints for Trimethoprim/sulfamethoxazole. No specific performance metrics (like sensitivity, specificity, accuracy) or a table comparing them to acceptance criteria are provided in this regulatory letter.
| Acceptance Criteria (MIC Breakpoints) | Reported Device Performance |
|---|---|
| Susceptible ≤ 2 µg/ml | Not reported in this document |
| Resistant ≥ 4 µg/ml | Not reported in this document |
The document states: "This 510(k) application is for System U3/Trimethoprim/sulfamethoxazole susceptibility testing based on the MIC breakpoints of Susceptible ≤ 2 µg/ml and Resistant ≥ 4 µg/ml for use with non-fastidious Gram negative and Gram positive aerobic bacteria." This defines the criteria the device aims to meet.
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective):
- Sample size for the test set: Not available in this document.
- Data provenance: Not available in this document.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not available in this document.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:
- Not available in this document.
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:
- Not applicable/Not available. This device is an in vitro diagnostic for antimicrobial susceptibility testing, not an AI-assisted imaging device that would typically involve human readers interpreting images.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- This device, System U3™, is described as a "qualitative technique for antimicrobial susceptibility testing" and an "antibiotic gradient with MIC break-point concentrations." It functions as an in vitro diagnostic test. It's likely designed for standalone performance in a laboratory setting to determine susceptibility, meaning the result is read directly from the test. However, the exact "standalone performance" metrics (like accuracy vs. a gold standard) are not provided in this regulatory letter.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For antimicrobial susceptibility testing, the "ground truth" (or reference method) typically involves a standardized reference method for MIC determination, such as broth microdilution or agar dilution, against which the device's results are compared. The document does not specify the exact ground truth method used in the studies supporting this 510(k) submission.
8. The sample size for the training set:
- Not available in this document. This document pertains to a 510(k) submission, not typically a machine learning device that requires "training sets" in the same way. Performance data would usually come from validation studies.
9. How the ground truth for the training set was established:
- Not applicable/Not available, as this is not an AI/machine learning device that would have a "training set" in the conventional sense. The ground truth for validation (if discussed) would likely be established using a reference method for antimicrobial susceptibility testing.
§ 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).