(25 days)
VITEK® 2 Streptococcus Ceftriaxone is designed for antimicrobial susceptibility testing of Streptococcus species. VITEK® 2 Streptococcus 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 following microorganism, according to the FDA label for this antimicrobial.
Active In Vitro and in Clinical Infections against:
Streptococcus pneumoniae Streptococcus pyogenes Streptoccocus agalactiae viridans group streptococci
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. 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 with 0.45% to 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, sealing and loading operation. The VITEK® 2 Systems monitor the growth of each well in the card over a defined period of time (up to 36 hours for yeast). At the completion cycle, a report is generated that contains the MIC value along with the interpretive category result for each antimicrobial contained on the card.
Acceptance Criteria and Study Details for VITEK® 2 Streptococcus Ceftriaxone
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria for antimicrobial susceptibility testing (AST) systems are typically defined by regulatory guidance documents, such as the FDA Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems. These guidelines specify performance metrics for essential agreement (EA) and category agreement (CA) when comparing the investigational device to a reference method.
| Metric | Acceptance Criteria (Typically per FDA Guidance for AST systems) | Reported Device Performance |
|---|---|---|
| Overall Essential Agreement (EA) | ≥ 90% (Standard criterion for AST systems) | 98.9% |
| Overall Category Agreement (CA) | ≥ 90% (Standard criterion for AST systems) | 97.2% |
| Reproducibility | Acceptable | Acceptable |
| Quality Control | Acceptable | Acceptable |
Note: The provided document does not explicitly state the numerical acceptance criteria for Overall Essential Agreement and Overall Category Agreement. However, the reported performance of 98.9% EA and 97.2% CA is well above the commonly accepted threshold of 90% for these metrics in AST systems, as outlined in the "FDA Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA. Issued August 28, 2009," which is referenced in the submission.
2. Sample Size and Data Provenance for the Test Set
- Sample Size: The document does not explicitly state the exact sample size in terms of the number of isolates or test runs. It mentions an "external evaluation was conducted with fresh and stock clinical isolates, as well as a set of challenge strains." This suggests a diverse collection of microbial samples.
- Data Provenance: The document does not specify the country of origin of the data. It indicates the study involved "fresh and stock clinical isolates, as well as a set of challenge strains," which implies a combination of real-world clinical samples and laboratory-maintained collections. The study was conducted as an "external evaluation." It is unclear if the study was retrospective or prospective.
3. Number of Experts and Qualifications for Ground Truth Establishment
The document does not specify the number of experts or their qualifications used to establish the ground truth.
4. Adjudication Method for the Test Set
The document does not describe any specific adjudication method.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not explicitly mentioned or performed. This study focuses on the performance of the automated system compared to a reference method, not on human reader performance with or without AI assistance.
6. Standalone Performance (Algorithm Only)
Yes, a standalone performance study was conducted. The VITEK® 2 system, which uses an automated algorithm, was compared directly against the CLSI broth microdilution reference method. The reported performance metrics (Essential Agreement and Category Agreement) reflect the algorithm's performance.
7. Type of Ground Truth Used
The ground truth used was the CLSI broth microdilution reference method. This is a recognized gold standard for determining minimum inhibitory concentrations (MICs) of antimicrobial agents.
8. Sample Size for the Training Set
The document does not explicitly state the sample size used for the training set. The study describes "an external evaluation" primarily focused on validating the device's performance against a reference method, rather than detailing the internal development and training of the algorithm.
9. How Ground Truth for the Training Set Was Established
The document does not provide details on how the ground truth for any potential training set was established. The focus of the 510(k) summary is on the validation of the final device against a reference method.
§ 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.”