(84 days)
PASCO MIC AND MIC/ID PANELS are used for quantitatively measuring (with the exception of the Breakpoint/D 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 Clindamycin to Pasco panels at concentrations of 0.015-2 mcg/ml for use in determining the susceptibility of S. pneumoniae and non-pneumococcal streptococci.
Varying concentrations of antimicrobial agents (usually in two-fold dilutions) are dispensed into the Pasco 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 text regarding the acceptance criteria and study for the Pasco MIC and MIC/ID Panels (Clindamycin):
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria (from FDA draft document "Review Criteria For Assessment Of Antimicrobial Susceptibility Devices" - May 1991) | Reported Device Performance (Clindamycin) |
|---|---|
| Essential Agreement (EA) for S. pneumoniae strains: Acceptable | 90.3% |
| Major (M) Errors for S. pneumoniae strains: Not observed | No Major Errors |
| Very Major (VM) Errors for S. pneumoniae strains: Not observed | No Very Major Errors |
| Minor Errors for S. pneumoniae strains: Not observed (likely implied acceptable if within EA) | No Minor Errors |
| Category Agreement (CA) for S. pneumoniae strains: Not explicitly stated as a numerical criteria, but 100% with 1 random minor error was observed. | 100% (with 1 random minor error within EA) |
| Essential Agreement (EA) for non-pneumococcal streptococci strains: Acceptable | 97.8% |
| Major (M) Errors for non-pneumococcal streptococci strains: Not observed | No Major Errors |
| Very Major (VM) Errors for non-pneumococcal streptococci strains: Not observed | No Very Major Errors |
| Minor Errors for non-pneumococcal streptococci strains: Not observed | No Minor Errors |
| Category Agreement (CA) for non-pneumococcal streptococci strains: Not explicitly stated as a numerical criteria, but 100% with no random minor errors was observed. | 100% (with no random minor errors) |
| Overall Essential Agreement for streptococci: Not explicitly stated, but 93.8% was reported. | 93.8% |
| QC Endpoints for S. pneumoniae ATCC 49619: Within recommended NCCLS acceptable range | Within recommended NCCLS acceptable range |
| Reproducibility: Not explicitly stated as a numerical criteria, but "100% within the acceptable plus or minus 1 dilution" was observed. | 100% within the acceptable plus or minus 1 dilution |
2. Sample Size Used for the Test Set and Data Provenance:
- Test Set Sample Sizes:
- S. pneumoniae strains: 101
- Non-pneumococcal streptococci strains: 130
- QC organism (S. pneumoniae ATCC 49619): used throughout testing (number of individual tests not specified, but likely repeated measurements)
- Reproducibility testing: 12 organisms at each of two sites, with 7 organisms producing on-scale endpoints.
- Data Provenance: The study was conducted using "CDC challenge strains and clinical isolates," suggesting a mix of standardized laboratory strains and real-world patient samples. The testing was performed at "two sites." The country of origin is not explicitly stated, but given the FDA submission, it is highly likely to be the USA. The study appears to be prospective comparative testing, as new panels were prepared and then tested against a reference panel.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications:
The document does not provide information on the number or qualifications of experts used to establish the ground truth. Ground truth in antimicrobial susceptibility testing for a device like this would typically involve a reference method (e.g., broth microdilution or agar dilution) interpreted by trained laboratory personnel.
4. Adjudication Method for the Test Set:
The document does not specify an adjudication method. In this context, it's less about expert adjudication of discrepancies (as might be seen in image interpretation) and more about the comparison of results from the investigational device against the established reference method standard. Discrepancies would be categorized as Major, Very Major, or Minor errors based on predefined criteria, rather than a human adjudication process.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
A MRMC comparative effectiveness study was not performed. This type of study is more common for diagnostic devices that rely on human interpretation (e.g., radiology AI). The Pasco device is an automated in vitro diagnostic for antimicrobial susceptibility, so human reader performance with and without AI assistance is not applicable.
6. Standalone Performance:
Yes, a standalone performance study was done. The entire summary of substantial equivalence testing describes the performance of the Pasco panels (the algorithm/device) compared to a reference standard. The metrics like Essential Agreement, Major/Very Major/Minor errors, Category Agreement, QC endpoints, and Reproducibility are all measures of the device's standalone performance.
7. Type of Ground Truth Used:
The ground truth used was based on comparison to a reference panel. Specifically, "Comparative testing of the Pasco test panel to a reference panel was performed." In microbiology, this usually implies a validated, standard antimicrobial susceptibility testing method (e.g., a CLSI-compliant broth microdilution method) as the gold standard for determining the true MIC and category.
8. Sample Size for the Training Set:
The document does not mention a training set. This is a traditional microbiology device (panels with antimicrobial agents), not a machine learning or AI-driven diagnostic device that typically requires a large training dataset for model development. The "device" here refers to the pre-prepared panels, and its performance is evaluated against established methods.
9. How the Ground Truth for the Training Set Was Established:
As there is no mention of a training set (see point 8), 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).