(33 days)
Pasco MIC and MIC/ID 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.
This 510(k) notification is for the addition of the antimicrobial Telithromycin at concentrations of 0.015 - 4 mcg/ml to Pasco Panels for use in testing Streptococcus pneumoniae and Streptococcus spp. other than Streptococcus pneumoniae. Telithromycin 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
Streptococcus pneumoniae (including multi-drug resistant isolates (MDRSP))
Active In Vitro but their clinical significance is unknown:
Aerobic gram-positive microorganisms
Streptococcus pyogenes (erythromycin susceptible isolates only) Streptococci (Lancefield groups C and G) Viridans group streptococci
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.
The provided 510(k) summary describes the acceptance criteria and study results for the Pasco MIC and MIC/ID Panels for Telithromycin.
1. Table of Acceptance Criteria and Reported Device Performance
| Measure | Acceptance Criteria (Implied by context of Antimicrobial Susceptibility Test (AST) Systems Guidance) | Reported Device Performance (Target organisms: Streptococcus pneumoniae and Streptococcus spp. other than S. pneumoniae) |
|---|---|---|
| Essential Agreement (EA) | Acceptable (typically >90% for AST systems) | 99.00% |
| Category Agreement (CA) | Acceptable (typically >90% for AST systems) | 100% |
| Very Major (VM) Errors | None (critical to prevent under-reporting resistance) | 0 |
| Major (M) Errors | None (critical to prevent over-reporting resistance) | 0 |
| Minor Errors | Acceptable (less critical than VM/M errors, but still tracked) | 0 |
| QC Endpoints | Acceptable for NCCLS recommended QC organisms | Acceptable |
| Inter-site Reproducibility (MIC results) | Acceptable (e.g., within 1 dilution for 95% or more) | 100% |
| Intra-site Reproducibility (MIC results) | Acceptable (e.g., within 1 dilution for 95% or more) | 100% |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: 570 challenge and clinical Streptococcus pneumoniae and Streptococcus spp. other than S. pneumoniae strains.
- Data Provenance: The data included "challenge strains, fresh clinical isolates, stock clinical isolates and QC strains." Testing was conducted at "three test sites." The specific country of origin is not explicitly stated, but given the submission to the FDA, it is highly likely to be U.S.-based or follow U.S. regulatory guidelines for data collection. The use of "fresh clinical isolates" suggests a prospective component, alongside "stock clinical isolates" which could be considered retrospective if they were banked prior to the study design.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
The document does not specify the number of experts used or their qualifications for establishing the ground truth. For antimicrobial susceptibility testing, the "ground truth" is typically established by a reference methodology performed by trained laboratory personnel, rather than expert clinicians or radiologists.
4. Adjudication Method for the Test Set
The document does not explicitly describe an adjudication method. In AST studies, ground truth is usually determined by established reference methodologies (e.g., broth microdilution according to CLSI/NCCLS guidelines) and confirmed by quality control strains, rather than an expert consensus adjudication process. The comparison is directly between the new device's results and the reference method's results.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not performed. This type of study is more common for diagnostic imaging devices where human interpretation is a key component. The Pasco MIC and MIC/ID Panels are automated or semi-automated devices for reading antimicrobial susceptibility, and the "readers" are the devices themselves or laboratory technicians following standardized procedures, not typically "human readers" in the sense of a MRMC study.
6. Standalone Performance Study
Yes, a standalone performance study was done. The entire study describes the performance of the Pasco MIC and MIC/ID Panels (the algorithm/device) against a reference methodology without human interpretation influencing the measurement of MICs. The "Essential Agreement" and "Category Agreement" metrics, along with error rates, reproducibility, and QC endpoints, are all measures of the device's standalone performance.
7. Type of Ground Truth Used
The ground truth used was established by reference methodology. The text states: "Challenge strains, fresh clinical isolates, stock clinical isolates and QC strains were tested concurrently using both Pasco methodology and reference methodology...". For AST, reference methodology typically refers to a standardized method like broth microdilution as defined by clinical and laboratory standards organizations (e.g., NCCLS/CLSI).
8. Sample Size for the Training Set
The document does not specify a separate "training set" sample size or discuss how the device was trained. For AST devices like these, particularly older ones, the "training" equivalent often involves calibrating the instrument/methodology to match established reference methods and NCCLS (now CLSI) guidelines, rather than machine learning on a distinct training dataset. The development and validation process would involve internal testing and optimization before the formal pre-market notification study.
9. How the Ground Truth for the Training Set Was Established
As no separate training set is explicitly mentioned or detailed as being used in the context of device "training" (as understood in modern AI/ML terms), the document does not provide information on how ground truth for such a set might have been established. Any internal development and calibration would have also relied on established reference methods and QC strains.
§ 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).