(68 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 Spartloxacin to Pasco panels at concentrations of 4-0.03 mcg/ml for use in determining the susceptibility of S. pneumoniae.
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 a breakdown of the acceptance criteria and study details based on the provided text:
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 (Sparfloxacin on Pasco MIC/ID Panels) |
|---|---|
| Acceptable Essential Agreement (EA) | S. pneumoniae (101 strains): 99.4% EA |
| Non-pneumococcal streptococci (130 strains): Initial testing: 98.5% EA; Retesting: 99.3% EA | |
| No Major (M) Errors | S. pneumoniae: No major errors |
| Non-pneumococcal streptococci: No major errors | |
| No Very Major (VM) Errors | S. pneumoniae: No very major errors |
| Non-pneumococcal streptococci: No very major errors | |
| Minor Errors (implied low number or resolution upon retest) | S. pneumoniae: No minor errors |
| Non-pneumococcal streptococci: One minor error resolved upon retest; 6 random minor errors noted (all within EA) | |
| Acceptable Category Agreement (CA) | S. pneumoniae: 100% CA |
| Non-pneumococcal streptococci: 100% CA | |
| QC endpoints for QC organism within recommended NCCLS acceptable range | S. pneumoniae ATCC 49619: Within recommended NCCLS acceptable range for both reference and Pasco panels |
| Reproducibility (% within +/- 1 dilution) | 12 organisms at each site: 100% within acceptable +/- 1 dilution |
2. Sample Sizes and Data Provenance
- Test Set Sample Size:
- 101 strains of S. pneumoniae
- 130 strains of non-pneumococcal streptococci
- 12 organisms for reproducibility testing (at each of two sites)
- Data Provenance: The study was conducted at "two sites" using "CDC challenge strains and clinical isolates." This indicates the data includes both well-characterized laboratory strains and real-world patient samples. The specific country of origin is not explicitly stated, but "CDC" (Centers for Disease Control and Prevention) suggests a US context. The study is prospective in design for the comparative testing of the Pasco panel against a reference method.
3. Number of Experts and Qualifications
The document does not explicitly state the number of experts used to establish the ground truth or their specific qualifications for this particular study. It refers to "reference panel" and "CDC challenge strains," implying established methods for determining susceptibility.
4. Adjudication Method
The document does not describe a specific adjudication method like "2+1" or "3+1." The results are presented as direct comparisons to a "reference panel." For the one minor error in non-pneumococcal streptococci, it states it was "resolved upon retest," which implies a form of re-evaluation, but not necessarily a multi-expert adjudication process.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No. This study is an in vitro diagnostic study comparing a device's performance to a reference method, not an MRMC study assessing human reader improvement with or without AI assistance.
6. Standalone Performance
Yes, this study describes the standalone performance of the Pasco MIC and MIC/ID panels (with Sparfloxacin) in determining antimicrobial susceptibility. The performance metrics (Essential Agreement, Category Agreement, error rates) are inherent to the device's ability to produce results.
7. Type of Ground Truth Used
The ground truth was established by a "reference panel" and using "CDC challenge strains." This implies a reference method or gold standard test for antimicrobial susceptibility testing, which provides the true MIC values or category results against which the Pasco panel's performance is measured.
8. Sample Size for the Training Set
The document does not explicitly mention a "training set" or its sample size. This type of antimicrobial susceptibility device typically relies on established manufacturing procedures and analytical validation rather than a separate machine learning training phase. The "routine manufacturing procedures" and quality control (QC) processes ensure the consistency and accuracy of the pre-prepared panels.
9. How Ground Truth for Training Set Was Established
As no specific "training set" or machine learning model is described, the concept of establishing ground truth for a training set is not applicable here. The device's underlying principles are based on microbiological growth inhibition and biochemical reactions, where the "ground truth" for developing and manufacturing the panels themselves likely stems from extensive historical microbiological data, reference methods, and quality control specifications (e.g., NCCLS standards).
§ 866.1620 Antimicrobial susceptibility test disc.
(a)
Identification. An antimicrobial susceptibility test disc is a device that consists of antimicrobic-impregnated paper discs used to measure by a disc-agar diffusion technique or a disc-broth elution technique the in vitro susceptibility of most clinically important bacterial pathogens to antimicrobial agents. In the disc-agar diffusion technique, bacterial susceptibility is ascertained by directly measuring the magnitude of a zone of bacterial inhibition around the disc on an agar surface. The disc-broth elution technique is associated with an automated rapid susceptibility test system and employs a fluid medium in which susceptibility is ascertained by photometrically measuring changes in bacterial growth resulting when antimicrobial material is eluted from the disc into the fluid medium. Test results are used to determine the antimicrobial agent of choice in the treatment of bacterial diseases.(b)
Classification. Class II (performance standards).