(82 days)
PASCO MC 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 Quinupristin to Pasco panels at concentrations of 8-0.03 mcg/ml for use in determining the susseptibility of Staphylococcus aureus (methicillin-susceptible strains only) and Enterococcus faecium (Vancomycin-resistant and multidrug resistant strains only).
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 requested information based on the provided text, focusing on the study conducted for Quinupristin in Pasco MIC and MIC/ID Panels:
1. Table of Acceptance Criteria and Reported Device Performance
| Performance Metric | Acceptance Criteria (Implicit from "acceptable" and context) | Reported Device Performance (Gram-Positive Strains) | Reported Device Performance (Gram-Negative Strains) |
|---|---|---|---|
| Essential Agreement (EA) | Acceptable agreement (no explicit %) | 100% | 99.7% (initial), 100% (retesting) |
| Major Errors (M) | No major errors | 0 | 0 |
| Very Major Errors (VM) | No very major errors | 0 | 0 |
| Minor Errors (m) | Acceptable minor errors (within EA) | 4 (within EA) | 1 (within EA) |
| Category Agreement (CA) | Acceptable agreement (no explicit %) | 100% | 100% |
| Reproducibility (% within +/- 1 dilution) | Acceptable (no explicit %) | 99.5% (overall) | 99.5% (overall) |
| QC Endpoints | Within recommended acceptable ranges listed in product information and NCCLS | Within acceptable ranges | Within acceptable ranges |
Note: The document states that performance "supports Substantial Equivalence as outlined in the FDA draft document 'Review Criteria For Assessment Of Antimicrobial Susceptibility Devices' (May 1991)." This FDA document would contain the specific numerical acceptance criteria. Without access to that specific document, the exact numerical thresholds for "acceptable" essential agreement, category agreement, and minor error rates are not explicitly stated in the provided text, but the reported performance achieved "acceptable" status.
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size:
- Gram-positive strains: 321
- Gram-negative strains: 334
- Reproducibility testing: 12 organisms at each of two sites (total could be inferred as 24, but specific count for the 99.5% calculation of "5 organisms with on-scale endpoints" is not definitively stated).
- Data Provenance:
- Country of Origin: Not explicitly stated, but the submission is to the FDA (United States) and Pasco Laboratories is in Wheat Ridge, Colorado, suggesting US data.
- Retrospective or Prospective: The test panels were "prepared in-house at Pasco using routine manufacturing procedures" and "Comparative testing... was performed at two sites using CDC challenge strains and clinical isolates." This indicates a prospective study where new test panels were created and tested with specific strains.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
- Number of Experts: Not explicitly stated.
- Qualifications of Experts: Not explicitly stated.
4. Adjudication Method for the Test Set
- Adjudication Method: Not explicitly described. The comparison was to a "reference panel," implying a comparison to an established method (the "ground truth"). The text doesn't detail how discrepancies between the test panel and reference panel were resolved or adjudicated beyond the listed error types (Major, Very Major, Minor).
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
- MRMC Study: No. This document describes the performance of an Antimicrobial Susceptibility Test device (a laboratory test) against a reference method, not an AI-assisted diagnostic imaging or interpretation system involving human readers. Therefore, an MRMC study with AI assistance is not applicable here.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
- Standalone Performance: Yes, in a sense. The Pasco MIC and MIC/ID Panels are designed to automatically determine the MIC based on visible growth or color changes, and then those results are interpreted. The comparative testing described is essentially a standalone performance evaluation of the device's ability to accurately determine MIC and category results compared to a reference method. It's an algorithm/device-only performance in the context of the assay's output.
7. The Type of Ground Truth Used
- Type of Ground Truth: "Reference panel." This refers to a comparison against an established, validated method for determining antimicrobial susceptibility, implicitly considered the gold standard for this type of testing. "CDC challenge strains" were also used, which are characterized strains with known susceptibilities, further strengthening the ground truth.
8. The Sample Size for the Training Set
- Training Set Sample Size: Not explicitly stated. The document describes the testing of the device for a specific antimicrobial (Quinupristin), not the development or training of the device itself. The Pasco MIC and MIC/ID panels are established devices, and this submission is for the addition of a new antimicrobial. Therefore, it's unlikely a "training set" in the machine learning sense was used for this specific submission. The "routine manufacturing procedures" and "CDC challenge strains" suggest a validation and verification process, not an iterative training process for an algorithm.
9. How the Ground Truth for the Training Set Was Established
- Ground Truth for Training Set: Not applicable, as no training set (in the machine learning sense) is described for this specific submission. The established "reference panel" and "CDC challenge strains" would serve as the basis for validating the performance of newly included antimicrobial agents.
§ 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).