(230 days)
For use in determining antimicrobial agent susceptibility and/or identification to the species level of aerobic and facultatively anaerobic gram-negative bacilli.
This submission requests clearance of the following new Indication for Use:
Panels containing Cefpodoxime, Ceftazidime, Aztreonam Cefotaxime, or Ceftriaxone at 1 ug/ml can be used to screen for Escherichia coli, Klebsiella oxytoca, or K. pneumoniae strains suspected of producing extended-spectrum beta-lactamases (ESBLs).
An alternate method is required for confirmation testing.
Microdilution Minimum Inhibitory Concentration (MIC) Panels. MicroScan® Dried Gram Negative MIC/Combo Panels with Cefpodoxime, Ceftazidime, Aztreonam, Cefotaxime, Ceftriaxone.
This document describes the acceptance criteria and the study conducted for MicroScan® Dried Gram Negative MIC/Combo Panels with certain antimicrobial agents to detect suspected Extended-Spectrum Beta-Lactamases (ESBLs) in specific bacterial strains.
1. Table of Acceptance Criteria and Reported Device Performance
The provided text does not explicitly state acceptance criteria in a quantitative format (e.g., minimum sensitivity/specificity thresholds). However, it implies acceptable performance based on reproducibility and quality control. The efficacy study aimed to confirm acceptability by comparing panel results against molecular characterization data.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Efficacy for ESBL Detection | Comparability of panel susceptibility results against molecular characterization data for ESBL and non-ESBL producing strains and AmpC-type strains. The goal is to confirm the acceptability of the MicroScan panels for detecting suspected ESBLs. | The "Efficacy study was designed to confirm the acceptability of the MicroScan® Dried Gram Negative Cefpodoxime, Ceftazidime, Aztreonam, Cefotaxime, Ceftriaxone antimicrobial agents for detection of suspected ESBLs (E. coli, K. oxytoca, and K. pneumoniae) by comparing the panel susceptibility results against previously generated molecular characterization data." While the specific numerical agreement is not provided, the submission was cleared by the FDA, implying that the data presented demonstrated acceptable efficacy for the intended use of screening for suspected ESBLs. |
| Reproducibility (Inoculum and Instrument) | >95% agreement with the comparative system. | "Inoculum and instrument reproducibility testing with the MicroScan® Dried Gram Negative Cefpodoxime, Ceftazidime, Aztreonam, Cefotaxime, Ceftriaxone antimicrobial agents demonstrated acceptable reproducibility with >95% of the results in agreement with the comparative system, regardless of which inoculum method (i.e., Turbidity, Log, and Prompt), or instrument (autoScan®-4 and WalkAway® System) was used." |
| Quality Control | Acceptable Quality Control throughout each phase of the ESBL evaluation. | "The MicroScan® Dried Gram Negative Cefpodoxime, Ceftazidime, Aztreonam, Cefotaxime, Ceftriaxone antimicrobial agents demonstrated acceptable Quality Control throughout each phase of the ESBL evaluation." |
2. Sample Size Used for the Test Set and Data Provenance
- Test Set Sample Size: The document states that the efficacy testing was conducted with "ESBL and non-ESBL producing strains and AmpC-type strains." The exact number of strains used in the test set is not specified in the provided text.
- Data Provenance: Not explicitly stated. The document refers to "previously generated molecular characterization data," but the origin (e.g., country, specific labs) is not detailed. The study itself appears to be conducted by Dade MicroScan Inc. (USA). The study is retrospective in the sense that molecular characterization data was "previously generated," and the panel results were compared against this existing data.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
This information is not provided. The ground truth ("molecular characterization data") was "previously generated," but details on the experts involved in establishing this ground truth are absent.
4. Adjudication Method for the Test Set
This information is not provided. The comparison was against "previously generated molecular characterization data," implying a direct comparison rather than an adjudication process between human readers/interpreters within the scope of the device's performance evaluation.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size
No, an MRMC comparative effectiveness study, as typically understood for human readers, was not performed. This study focuses on the in vitro diagnostic device's ability to detect ESBLs by comparing its results to a ground truth (molecular characterization data), not on how human readers perform with or without AI assistance.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, this study represents a standalone performance evaluation of the MicroScan® Dried Gram Negative MIC/Combo Panels. The device itself (the panel and its interpretation via instrument) is being evaluated for its ability to detect ESBLs, independent of human interpretation or assistance beyond the standard operation of the instrument.
7. The Type of Ground Truth Used
The ground truth used was molecular characterization data. The document states, "...comparing the panel susceptibility results against previously generated molecular characterization data." This suggests genetic or biochemical testing to definitively identify ESBL-producing strains.
8. The Sample Size for the Training Set
The document does not mention a separate "training set" or detail for algorithm development or machine learning. The study focuses on evaluating the performance of existing panels for a new indication for use. Therefore, no sample size for an algorithm training set is applicable or provided.
9. How the Ground Truth for the Training Set Was Established
Since no training set for an algorithm is discussed, this information is not applicable. The "previously generated molecular characterization data" served as the reference standard for the test set evaluation.
§ 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).