(258 days)
VITEK® 2 Gram Negative Ceftriaxone is designed for antimicrobial susceptibility testing of Gram-negative bacilli. VITEK® 2 Gram Negative Ceftriaxone is a quantitative test 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. Ceftriaxone 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 clinical infections:
Escherichia coli
Enterobacter aerogenes
Klebsiella pneumoniae
Proteus mirabilis
Klebsiella oxytoca
Serratia marcescens
In vitro data available but clinical significance is unknown:
Citrobacter freundii
Citrobacter koseri (formerly Citrobacter diversus)
Providencia species (including Providencia rettgeri)
Shigella species
Salmonella species (including Salmonella typhi)
The VITEK® 2 Antimicrobial Susceptibility Test (AST) is intended to be used with the VITEK® 2 System for the automated quantitative or qualitative susceptibility testing of isolated colonies for the most clinically significant aerobic gram-negative bacilli, Staphylococcus spp., Enterococcus spp., Streptococcus spp., S. pneumoniae, and clinically significant yeast.
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.
Here's a breakdown of the acceptance criteria and study information for the VITEK® 2 Gram Negative Ceftriaxone device, as extracted from the provided text:
Acceptance Criteria and Device Performance
| Acceptance Criteria | Reported Device Performance (%) |
|---|---|
| Overall Essential Agreement (EA) | 97.5% |
| Overall Category Agreement (CA) | 99.0% |
Note: The document states that a performance limitation will be taken for Proteus vulgaris.
Study Information
2. Sample size used for the test set and the data provenance:
- Test Set Size: Not explicitly stated as a single number. The study utilized "fresh and stock clinical isolates, as well as a set of challenge strains."
- Data Provenance: Not explicitly stated (e.g., country of origin). The study involved "clinical isolates" and a "retrospective" study design can be inferred as "stock clinical isolates" were used.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Number of Experts: Not specified.
- Qualifications of Experts: Not specified.
4. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- Not specified. However, the external evaluation compared the device's performance directly against the CLSI broth microdilution reference method, which serves as the gold standard for antimicrobial susceptibility testing. This implies the CLSI method itself is the 'adjudication' or 'ground truth' establishment.
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:
- No, an MRMC comparative effectiveness study was not done. This device is an automated antimicrobial susceptibility testing system, not an AI-assisted diagnostic tool designed to improve human reader performance.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, a standalone performance study was done. The VITEK® 2 system is an automated device, and the study evaluated its performance (algorithm only) compared to the reference method.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- The ground truth used was the CLSI broth microdilution reference method incubated at 16 - 20 hours. This is a laboratory-based gold standard for determining Minimum Inhibitory Concentration (MIC) values.
8. The sample size for the training set:
- Not explicitly mentioned. The document primarily focuses on the external evaluation (test set).
9. How the ground truth for the training set was established:
- Not explicitly mentioned. Assuming standard practices for such devices, the training data would likely also have been established using a recognized reference method like CLSI broth microdilution.
§ 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.”