Search Results
Found 1 results
510(k) Data Aggregation
(90 days)
VITEK® 2 AST-Gram Negative Tobramycin is designed for antimicrobial susceptibility testing of Gram negative bacilli 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 Negative Tobramycin is a qualitative test. Tobramycin has been shown to be active against most strains of the microorganisms listed below, according to the FDA label for this antimicrobial.
Active in vitro and in clinical infections: Citrobacter spp. Enterobacter spp. Escherichia coli Klebsiella spp. Morganella morganii Pseudomonas aeruginosa Proteus mirabilis Proteus vulgaris Providencia spp. Serratia spp.
The VITEK® 2 Antimicrobial Susceptibility Test (AST) is intended to be used with the VITEK® 2 Systems for the automated quantitative or qualitative susceptibility testing of isolated colonies for the most clinically significant aerobic gram-negative bacilli, Staphylococus spp., Enterococcus spp., Streptococcus spp. and clinically significant yeast.
The antimicrobial presented in VITEK® 2 AST-GN Cards is in concentrations equivalent by efficacy to standard method concentrations in mcg/ml. 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 (up to 18 hours). 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 document describes the VITEK® 2 AST-Gram Negative Tobramycin device, an automated antimicrobial susceptibility testing system.
Here's an analysis based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are implied by the "acceptable performance" thresholds mentioned in the document, which align with FDA guidance for AST systems.
| Performance Metric | Acceptance Criteria (Implied by context of FDA Guidance) | Reported Device Performance (VITEK® 2 AST-GN Tobramycin) |
|---|---|---|
| Overall Essential Agreement | Not explicitly stated but generally high (e.g., >90%) | 98.5% |
| Overall Category Agreement | Not explicitly stated but generally high (e.g., >90%) | 96.9% |
| Reproducibility | "Acceptable results" (specific % not given) | "Acceptable results" |
| Quality Control | "Acceptable results" (specific % not given) | "Acceptable results" |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size: Not explicitly stated as a single number. The study used "fresh and stock clinical isolates, as well as a set of challenge strains." The exact number of isolates for each category is not specified.
- Data Provenance: Not explicitly stated (e.g., country of origin, specific hospitals). The data is from an "external evaluation." It is implicitly prospective or a mix of retrospective (stock isolates) and prospective (fresh clinical isolates).
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
Not applicable. The ground truth for antimicrobial susceptibility testing is established by a reference laboratory method (CLSI broth microdilution), not by human experts interpreting images or clinical data.
4. Adjudication Method for the Test Set
Not applicable. The ground truth is determined by a standardized reference methodology (CLSI broth microdilution), so there is no need for expert adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
Not applicable. This is an in vitro diagnostic device for antimicrobial susceptibility testing, not a device that involves human readers interpreting cases (e.g., radiology images). Therefore, an MRMC study comparing human reader performance with and without AI assistance is not relevant.
6. Standalone Performance Study (Algorithm Only Without Human-in-the-Loop Performance)
Yes, a standalone performance study was done. The VITEK® 2 AST-GN Tobramycin device's performance (Essential Agreement and Category Agreement) was compared directly against the CLSI broth microdilution reference method. This is a measure of the device's algorithmic performance without human interpretation or intervention beyond sample preparation and loading.
7. Type of Ground Truth Used
The ground truth used was the CLSI broth microdilution reference method, which is a laboratory standard for determining minimum inhibitory concentrations (MICs) of antimicrobial agents.
8. Sample Size for the Training Set
Not explicitly stated. The document refers to "external evaluation" and "challenge strains" for the test set. It does not provide information specifically about a training set. For an AST system, "training" often refers to the development and optimization of the interpretive algorithms, which may involve internal strain collections and development data, but this information is not detailed in the provided text.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as details about a separate "training set" and its ground truth establishment are not provided in the document. The ground truth for the overall device's development and validation would consistently rely on established reference methods like CLSI broth microdilution.
Ask a specific question about this device
Page 1 of 1