(87 days)
VITEK® 2 AST-Gram Positive Dalbavancin is designed for antimicrobial susceptibility testing of Gram positive microorganisms and is intended for use with the VITEK® 2 and VITEK® 2 Compact Systems as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents. VITEK® 2 AST-Gram Positive Dalbavancin is a quantitative test. Dalbavancin has been shown to be active against most strains of the microorganisms listed below, according to the FDA label for this antimicrobial.
The VITEK® 2 AST Cards are essentially miniaturized versions of the doubling dilution technique for determining the minimum inhibitory concentration (MIC) microdilution methodology. The isolate to be tested is diluted to a standardized concentration in 0.45 - 0.50% saline before being used to rehydrate the antimicrobial medium within the card. The VITEK® 2 automatically fills, seals and places the card into the incubator/reader. The VITEK® 2 Compact has a manual filling and sealing operation. The VITEK® 2 monitors the growth of each well in the card over a defined period of time (20-24 hours for Streptococi and 16-20 hours for Staphylococci and Enterococci). At the completion of the incubation cycle, a report is generated that contains the MIC value along with the interpretive category result for each antimicrobial contained on the card.
The provided text describes the VITEK® 2 AST-Gram Positive Dalbavancin (≤0.015 - ≥1 µg/mL) device, which is an antimicrobial susceptibility testing system.
Here's the breakdown of the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance:
The primary performance metric provided is "Overall Performance (with the reference method)" which is broken down into Essential Agreement (EA), Category Agreement (CA), and specific types of errors (VME, ME, mE).
| Metric | Acceptance Criteria (Implied by FDA Guidance) | Reported Device Performance |
|---|---|---|
| Essential Agreement (EA) | Not explicitly stated, but typically ≥ 90% | 98.1% |
| Category Agreement (CA) | Not explicitly stated, but typically ≥ 90% | 100.0% |
| Very Major Error (VME) | Not explicitly stated, but typically ≤ 1.5% | 0.0% |
| Major Error (ME) | Not explicitly stated, but typically ≤ 3.0% | 0.0% |
| Minor Error (mE) | Not explicitly stated, but typically ≤ 10% | N/A (listed as "N/A" for CA) |
Note: The acceptance criteria for EA, CA, VME, ME, and mE are inferred based on general FDA guidance for AST systems, as the specific numerical targets for acceptability are not directly stated in this document. The table in the document only provides values for %EA and %CA, and then VME, ME, mE which appear to apply to %CA. It's unclear if there are separate VME, ME, and mE targets for %EA based on the table's structure.
2. Sample Size Used for the Test Set and Data Provenance:
- Test Set Sample Size: Not explicitly stated as a single number. The study involved "fresh and stock clinical isolates, as well as a set of challenge strains." Without a total count, the exact sample size for the test set is unknown.
- Data Provenance: The document does not specify the country of origin of the data. It states the evaluations were "external." The isolates were "fresh and stock clinical isolates, as well as a set of challenge strains," indicating a mix of real-world and curated samples. It is a prospective study as it was "designed to confirm the acceptability."
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of those Experts:
- Number of Experts: Not applicable. The ground truth was established by a reference method, not by human experts.
4. Adjudication Method for the Test Set:
- Adjudication Method: Not applicable. The ground truth was established by the CLSI broth microdilution reference method, which is a standardized laboratory procedure, not an expert-based adjudication.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done:
- MRMC Study: No, an MRMC comparative effectiveness study was not done. This device is an automated antimicrobial susceptibility testing system, so human reader performance with or without AI assistance is not relevant.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done:
- Standalone Performance: Yes, the study assesses the standalone performance of the VITEK® 2 AST-Gram Positive Dalbavancin system (algorithm only), comparing its results directly to the CLSI broth microdilution reference method.
7. The Type of Ground Truth Used:
- Ground Truth Type: The ground truth was established using the CLSI broth microdilution reference method. This is considered a standardized, objective laboratory method.
8. The Sample Size for the Training Set:
- Training Set Sample Size: Not specified. The document describes an "external evaluation" for performance testing but does not provide details about a separate training set size or how the model was initially developed/trained.
9. How the Ground Truth for the Training Set was Established:
- Training Set Ground Truth: Not specified. Since a training set size is not provided, the method for establishing its ground truth is also not mentioned.
§ 866.1645 Fully automated short-term incubation cycle antimicrobial susceptibility system.
(a)
Identification. A fully automated short-term incubation cycle antimicrobial susceptibility system is a device that incorporates concentrations of antimicrobial agents into a system for the purpose of determining in vitro susceptibility of bacterial pathogens isolated from clinical specimens. Test results obtained from short-term (less than 16 hours) incubation are used to determine the antimicrobial agent of choice to treat bacterial diseases.(b)
Classification. Class II (special controls). The special control for this device is FDA's guidance document entitled “Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA.”