(65 days)
Thermo Scientific™ Oxoid™Antimicrobial Susceptibility Test (AST) Discs are used in the semi quantitative agar diffusion test method for in vitro susceptibility testing.
The Thermo Scientific Oxoid Meropenem/Vaborbactam Disc (30 can be used to determine susceptibility to Meropenem/Vaborbactam against the following bacteria for which Meropenem/Vaborbactam has been shown to be active both clinically and in vitro:
Escherichia coli
Klebsiella pneumoniae
Enterobacter cloacae species complex
Thermo Scientific Oxoid Meropenem/Vaborbactam Disc (30μg) MEV30 Antimicrobial Susceptibility Test Discs are 6mm. discs prepared by impregnating high quality absorbent paper with accurately determined amounts of Meropenem and Vaborbactam. The Disc is clearly marked on both sides with the code MEV30. The code designates the agent (Meropenem/Vaborbactam) and the drug content (30µg).
Oxoid discs are supplied in cartridges containing 50 discs each, there are 5 cartridges per pack. Each cartridge is individually sealed together with a desiccant capsule in a foil covered seethrough blister pack. Oxoid discs can be dispensed using an Oxoid Disc Dispenser.
Meropenem/Vaborbactam Disc (30μg) MEV30 Disc Content: Meropenem 20μg / Vaborbactam10μg.
The medical device under consideration is the Thermo Scientific Oxoid Meropenem/Vaborbactam Disc (30ug) MEV30, an Antimicrobial Susceptibility Test Disc.
Here's an analysis based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance:
The primary acceptance criterion appears to be Category Agreement (CA) with a predicate device.
| Acceptance Criterion (Implicit) | Reported Device Performance |
|---|---|
| High Category Agreement (CA) with predicate device | Enterobacteriaceae (Total=375): CA = 99.2% (372/375) |
| K. pneumoniae (184 isolates) | |
| Escherichia coli (121 isolates) | |
| Enterobacter cloacae spp. complex (35 isolates) | |
| Performance in accordance with antibiotic manufacturer recommendations | Product performance is in accordance with the recommendations of the manufacturer of the antibiotic. |
| Quality Control (QC) within acceptable ranges | Acceptable QC ranges established and tested (see Table 5.3) |
2. Sample Sizes Used for the Test Set and Data Provenance:
- Test Set Sample Size:
- 300 clinical isolates
- 75 challenge isolates
- Total: 375 isolates (Enterobacteriaceae specific, including K. pneumoniae, Escherichia coli, and Enterobacter cloacae spp. complex)
- Data Provenance: Not explicitly stated regarding country of origin or if prospective/retrospective. However, clinical isolates suggest real-world samples.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts:
This information is not provided in the document. The study compares the device against a "predicate device" and potentially "CLSI approved standards M02 and M100" for interpretation, rather than relying on human expert consensus for a de novo ground truth.
4. Adjudication Method for the Test Set:
This information is not provided. The study design focuses on direct comparison to a predicate device and adherence to established interpretive criteria.
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:
This is not applicable. The device is an antimicrobial susceptibility test disc, not an AI-powered diagnostic tool requiring human reader interpretation in the context of an MRMC study. Its performance is determined by the zone diameter measurement.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done:
This is not applicable in the context of a typical standalone algorithm study for AI. The "device" itself (the disc) provides a direct output (zone diameter) which is then interpreted against established criteria. It doesn't involve an algorithm in the AI sense. However, the study did evaluate the device's performance independently, comparing its output to a predicate device and established criteria.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.):
The ground truth for the performance study is implicitly based on the results obtained from the predicate device (HardyDisk Meropenem/Vaborbactam 20/10 µg (MEV30), K172621) and the established susceptibility interpretive criteria (CLSI approved standards M02 and M100, presented in Table 5.2). The predicate device's performance would have previously been established as accurate.
8. The Sample Size for the Training Set:
This is not applicable/not provided. The device is a physical diagnostic disc, not a machine learning model that requires a training set in the conventional sense.
9. How the Ground Truth for the Training Set Was Established:
This is not applicable. As explained above, there is no "training set" for this type of device.
Summary of the Study:
The study was a comparative evaluation of the Thermo Scientific Oxoid Meropenem/Vaborbactam Disc against a legally marketed predicate device (Hardy Meropenem Vaborbactam disk) for determining antimicrobial susceptibility.
- Objective: To demonstrate that the performance of the new disc is equivalent to the predicate device.
- Methodology:
- Comparison of zone diameter measurements for 375 isolates (300 clinical, 75 challenge) of Enterobacteriaceae (including K. pneumoniae, E. coli, and E. cloacae spp. complex).
- Assessment of Category Agreement (CA) between the new device and the predicate.
- Quality Control (QC) and reproducibility studies were also performed.
- Results: A Category Agreement of 99.2% was achieved for Enterobacteriaceae (372 out of 375 isolates) when compared to the predicate device. The zone diameter interpretive criteria and acceptable quality control ranges were established based on CLSI standards.
- Conclusion: The study concluded that the disc performance was equivalent to the predicate device and in accordance with the recommendations of the antibiotic manufacturer.
Limitations Noted in the Document:
- The ability of the disc to detect resistance in species other than K. pneumoniae is unknown due to an insufficient number of resistant strains at the time of testing.
- Performance for Enterobacteriaceae with specific resistance mechanisms (overexpression of efflux pumps and/or lower expression of porins) is unknown.
§ 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).