(58 days)
PASCO MIC AND MIC/ID PANELS are used for quantitatively measuring (with the exception of the Breakpoint/ID panel which provides qualitative measurement or category results) the susceptibility of rapidly growing aerobic and facultative anaerobic bacterial pathogens to a battery of antimicrobial agents and determining the biochemical identification of those organisms. This 510(k) notification is for the addition of the antimicrobial Linezolid at concentrations of 0.25 - 8 mcg/ml to Pasco Panels. Linezolid has been shown to be active in vitro against most strains of microorganisms listed below, as described in the FDA-approved package insert for this antimicrobic. Active In Vitro and in Clinical Infectious Against: Aerobic Gram-positive microorganisms Enterococcus faecium (vancomycin-resistant strains only) Staphylococcus aureus (including methicillin-resistant strains) Active In Vitro but their clinical significance is unknown Aerobic Gram-positive microorganisms Enterococcus faecalis (including vancomycin-resistant strains) Enterococcus faecium (vancomycin-susceptible strains) Staphylococcus epidermidis (including methicillin-resistant strains) Staphylococcus haemolyticus
Pasco Panels are used for quantitatively measuring the susceptibility of rapidly growing aerobic and facultative anaerobic bacterial pathogens to a battery of antimicrobial agents and determining the biochemical identification of those organisms. Varying concentrations of antimicrobial agents (usually in two-fold dilutions) are dispensed into the Pasco microdilution panels and the panels are then frozen. Panels are thawed prior to use, inoculated with the test organisms, incubated the traditional 16-24 hours and panels are then observed for visible growth or color changes as described in the package insert. The lowest concentration of each antimicrobial agent with no apparent visible growth of the test organism is recorded as the minimum inhibitory concentration (MIC). Changes in pH and production of specific metabolites from growth in biochemical substrates are interpreted as described in the package insert for conventional tubed media.
Here's an analysis of the provided 510(k) summary regarding the PASCO MIC and MIC/ID Panels for Linezolid, structured to address your specific questions:
1. A table of acceptance criteria and the reported device performance
The document doesn't explicitly state quantitative acceptance criteria in a dedicated section. However, based on the conclusions and terminology used, the implicit acceptance criteria for this type of device (Antimicrobial Susceptibility Test) are high levels of "Essential Agreement" (EA) and "Category Agreement" (CA), and the absence of "very major," "major," or "minor" errors. Reproducibility is also a key criterion.
| Acceptance Criteria (Implicit) | Reported Device Performance |
|---|---|
| Essential Agreement (EA) | 99.9% |
| Category Agreement (CA) | 100% |
| Very Major Errors (VM) | 0 |
| Major Errors (M) | 0 |
| Minor Errors (m) | 0 |
| Reproducibility (Inter-site) | 100% |
| Reproducibility (Intra-site) | 100% |
| QC Endpoints for NCCLS organisms | Acceptable |
2. Sample size used for the test set and the data provenance
- Sample Size for Test Set:
- 413 challenge and clinical Staphylococcus spp.
- 365 challenge and clinical Enterococcus spp.
- For reproducibility testing: 10 organisms at each of 3 sites, tested in triplicate on 3 separate days (10 organisms * 3 sites * 3 days * 3 replicates = 270 individual tests for reproducibility).
- Data Provenance:
- The data includes "Challenge strains, fresh clinical isolates, stock clinical isolates and QC strains."
- Testing was conducted at "three test sites."
- The document does not specify the country of origin, but given the FDA submission, it's presumed to be within the US or compliant with US regulatory standards.
- The study appears to be prospective for the clinical isolates, as they were tested concurrently with both the Pasco methodology and reference methodology. Stock and challenge strains would also be part of a prospectively planned study.
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 summary. For Antimicrobial Susceptibility Testing (AST) devices, the ground truth is typically established by a recognized reference method (e.g., broth microdilution or agar dilution as per CLSI/NCCLS standards) rather than individual expert adjudication of results. The document states, "Challenge strains, fresh clinical isolates, stock clinical isolates and QC strains were tested concurrently using both Pasco methodology and reference methodology." The reference methodology serves as the ground truth.
4. Adjudication method for the test set
There was no human adjudication described for the test set results in the way one might see for imaging or pathology studies. Instead, the device's results were directly compared against a "reference methodology." The agreement percentages (EA, CA) and error rates (VM, M, m) indicate a direct comparison and calculation rather than an adjudicated consensus.
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
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This type of study is typically relevant for interpretative diagnostic devices where human reading is involved and the device provides assistance (e.g., AI in radiology). The Pasco device automates the measurement of MIC and identification, and the comparison is between the device and a reference method, not human readers. Therefore, the concept of "human readers improve with AI vs without AI assistance" does not apply here.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, a standalone performance evaluation was conducted. The Pasco device, described as giving specific quantitative MIC values and biochemical identification, is itself the "algorithm" or automated system. The reported performance metrics (EA, CA, error rates, reproducibility) are for the device's output compared to a reference standard, without human intervention in the interpretation of the device's primary output. The "human-in-the-loop" here would be laboratory personnel performing the setup and reading of the reference methodology and interpreting the final results for patient care, but the device's performance itself is standalone.
7. The type of ground truth used
The ground truth used was a reference methodology for antimicrobial susceptibility testing. The document states, "Challenge strains, fresh clinical isolates, stock clinical isolates and QC strains were tested concurrently using both Pasco methodology and reference methodology". For AST, the reference method (e.g., broth microdilution as per CLSI standards) is the gold standard for determining MICs.
8. The sample size for the training set
The document does not specify a separate training set or its sample size. This type of 510(k) submission for a diagnostic device usually focuses on verification and validation (V&V) testing (what you've termed the "test set") against a known standard. Device development (which might involve 'training' in a broad sense, especially for pattern recognition or instrument calibration) is usually internal to the manufacturer and not explicitly detailed as a 'training set' in the 510(k) summary in the same way an AI/ML model's training set would be.
9. How the ground truth for the training set was established
Since a separate "training set" with ground truth establishment is not mentioned for this type of device submission, this question is not applicable based on the provided information. The ground truth for the test set (reference methodology) is detailed above.
§ 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).