(227 days)
VITEK® 2 AST-YS Caspofungin is designed for antifungal susceptibility testing of Candida species 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 Yeast Caspofungin is a quantitative test. Caspofungin has been shown to be active against most isolates of the microorganisms listed below, according to the FDA label for this antifyingal.
Active in vitro and clinical infections: Candida albicans Candida glabrata Candida guilliermondii Candida krusei Candida parapsilosis Candida tropicalis
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 summary of the acceptance criteria and the study that proves the device meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Criteria Category | Acceptance Criteria (typically from FDA guidance) | Reported Device Performance (VITEK® 2 AST-YS Caspofungin) |
|---|---|---|
| Overall Essential Agreement | Not explicitly stated in the provided text as a numerical target, but implied to be high based on FDA Class II Special Controls Guidance Document. | 99.7% |
| Overall Category Agreement | Not explicitly stated in the provided text as a numerical target, but implied to be high based on FDA Class II Special Controls Guidance Document. | 99.8% |
| Reproducibility | Acceptable performance (as per FDA Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA) | Acceptable results |
| Quality Control | Acceptable performance (as per FDA Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA) | Acceptable results |
| Substantial Equivalence | Performance comparable to a legally marketed predicate device and CLSI broth microdilution reference method. | Demonstrated substantially equivalent performance when compared with the CLSI broth microdilution reference method. |
| Active Microorganisms | Active against specific Candida species according to FDA label for the antifungal. | Confirmed for: Candida albicans, Candida glabrata, Candida guilliermondii, Candida krusei, Candida parapsilosis, Candida tropicalis. |
Note: The specific numerical acceptance criteria for Essential Agreement and Category Agreement are often found in FDA guidance documents for AST systems, which are referenced (FDA Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA, issued August 28, 2009). While the document states that the device demonstrated "acceptable performance," it does not explicitly list the numerical thresholds from that guidance.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: Not explicitly stated as a total number. The study utilized "fresh and stock clinical isolates, as well as a set of challenge strains." The document does not specify the exact number of isolates for each category or the total.
- Data Provenance: The document indicates the use of "clinical isolates" (both fresh and stock) and "challenge strains." The country of origin is not specified, but the context implies data collected for regulatory submission within the U.S.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
- The document does not mention the use of experts to establish ground truth for the test set.
- Instead, the ground truth was established by a reference method: the CLSI broth microdilution reference method.
4. Adjudication Method for the Test Set
- None. The ground truth was established by comparison to a standardized reference method (CLSI broth microdilution), not through expert adjudication of images or clinical cases.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
- No. An MRMC comparative effectiveness study was not conducted as this device is an automated in vitro diagnostic for antimicrobial susceptibility testing, not a system involving human readers interpreting clinical cases with or without AI assistance. The performance is compared to a reference laboratory method.
6. If a Standalone Performance Study Was Done
- Yes. The study described is a standalone performance evaluation of the VITEK® 2 AST-YS Caspofungin system. It compares the results generated by the VITEK® 2 system (algorithm-driven interpretation of growth patterns) directly against the CLSI broth microdilution reference method. This is an "algorithm only" type of performance study for a diagnostic device.
7. The Type of Ground Truth Used
- Reference Method (CLSI Broth Microdilution): The ground truth was established by the CLSI broth microdilution reference method, incubated at 24 hours.
8. The Sample Size for the Training Set
- The document does not specify a separate "training set" or its sample size. For in vitro diagnostic devices like this, the development likely involves internal studies and database building, but the submission specifically focuses on the external evaluation data as the primary validation.
9. How the Ground Truth for the Training Set Was Established
- Since a training set is not explicitly mentioned or detailed in the document, how its ground truth was established is not provided. If a training set was used during the device's development, it would typically involve similar reference methods (like CLSI broth microdilution) to establish the correct susceptibility profiles the system is designed to learn from or emulate.
§ 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).