(32 days)
Pasco MIC and MIC/ID panels are used for quantitatively measuring (with the exception of the Breakpoint/ID panel which provides qualitative measurement of 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 Gemifloxacin at concentrations of 0.015 - 4 mcg/ml to Pasco Panels for use in testing Streptococcus pneumoniae and Streptococcus spp. other than S. pneumoniae. Gemifloxacin 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 penicillin-resistant strains)
Active In Vitro but their clinical significance is unknown
Aerobic Gram-positive microorganisms
Streptococcus pvogenes
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 the study conducted to demonstrate the substantial equivalence of the Pasco MIC and MIC/ID Panels for Gemifloxacin.
Here's a breakdown of the requested information:
1. Table of Acceptance Criteria and Reported Device Performance:
| Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Essential Agreement (EA) | High percentage (e.g., typically >90% to establish substantial equivalence based on FDA guidance for AST systems) | 99.7% for Streptococcus pneumoniae and Streptococcus spp. other than S. pneumoniae |
| Major (M) Errors | No significant number (typically very few or none are acceptable) | None observed |
| Very Major (VM) Errors | No significant number (typically very few or none are acceptable) | None observed |
| Category Agreement (CA) | Acceptable percentage (e.g., typically >90% based on FDA guidance for AST systems) | 99.0% |
| Minor Discrepancies | Low number, ideally within EA | 7 random minor discrepancies, all within EA with the exception of one. |
| Reproducibility (Inter-site) | High percentage (e.g., 95-100%) | 100% |
| Reproducibility (Intra-site) | High percentage (e.g., 95-100%) | 100% |
| QC Endpoints | Acceptable according to NCCLS recommended QC organisms | Acceptable for S. pneumoniae ATCC 49619 |
Explanation of Implied Acceptance Criteria: The document refers to "Substantial Equivalence as outlined in the FDA document 'Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA'." This guidance typically sets high thresholds for agreement (Essential Agreement, Category Agreement) and low thresholds for errors (Major and Very Major errors) for AST systems to be considered substantially equivalent.
2. Sample Size Used for the Test Set and the Data Provenance:
- Sample Size (Test Set): 570 challenge and clinical isolates (Streptococcus pneumoniae and Streptococcus spp. other than S. pneumoniae).
- Data Provenance: The study used "Challenge strains, fresh clinical isolates, stock clinical isolates and QC strains." The country of origin is not explicitly stated in this document but is generally assumed to be within the US for FDA submissions unless otherwise specified. The study included both retrospective (stock clinical isolates) and prospective (fresh clinical isolates) data components, along with pre-defined challenge and QC strains.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and the Qualifications of Those Experts:
- The document does not explicitly state the number of experts or their qualifications for establishing the ground truth.
- However, the "reference methodology" is used to establish the ground truth. This "reference methodology" for antimicrobial susceptibility testing typically refers to standardized methods like broth microdilution or agar dilution as described by CLSI (formerly NCCLS), which are overseen and interpreted by trained laboratory professionals (e.g., clinical microbiologists, medical technologists with expertise in AST).
4. Adjudication Method for the Test Set:
- The document does not explicitly describe an adjudication method for reconciling discrepancies between different readers or methods.
- The comparison is made between the "Pasco methodology" and "reference methodology." Any discrepancies (like minor discrepancies) are reported, but a formal adjudication process (e.g., a third expert review) is not detailed.
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 MRMC study was done. This submission is for an Antimicrobial Susceptibility Test (AST) panel, which is a laboratory diagnostic device, not an AI-driven imaging or diagnostic aid for human readers. It measures bacterial susceptibility directly. Therefore, the concept of "human readers improve with AI" is not applicable here.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
- This is a standalone device study. The "Pasco methodology" (the device under review) is compared directly to a "reference methodology." The performance metrics (EA, CA, errors, reproducibility) are derived from the device's output and compared to the ground truth established by the reference method. There is no mention of a human-in-the-loop component for the device's performance evaluation as it is an automated or semi-automated system for determining MICs.
7. The Type of Ground Truth Used:
- Expert Consensus / Reference Method Data: The ground truth was established by "reference methodology." For AST, this typically means a validated, gold-standard laboratory susceptibility testing method (e.g., broth microdilution or agar dilution according to CLSI guidelines), which serves as the consensus reference for determining true MIC values and susceptibility categories.
8. The Sample Size for the Training Set:
- Not Applicable / Not Explicitly Stated: This type of device (AST panel) does not typically involve a "training set" in the context of machine learning or AI models with algorithms that learn from data. The device's performance is based on its physical/chemical design and measurement principles, not on algorithmic learning from a large dataset. The "challenge strains, fresh clinical isolates, stock clinical isolates and QC strains" mentioned are part of the test set used for validation.
9. How the Ground Truth for the Training Set Was Established:
- Not Applicable: As there is no "training set" in the context of an AI/ML algorithm for this AST device, this question is not relevant. The ground truth for the test set was established by the "reference methodology" as described in point 7.
§ 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).