(17 days)
VITEK® 2 Gram Positive Telithromycin for Streptococcus pneumoniae is designed for antimicrobial susceptibility testing of Streptococcus pneumoniae. VITEK 2 Gram Positive Telithromycin for Streptococcus pneumoniae is a qualitative test. It 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.
The VITEK® 2 Antimicrobial Susceptibility Test (AST) is intended to be used with the VITEK® 2 and VITEK® 2 Compact Systems for the automated quantitative or qualitative susceptibility testing of isolated colonies for the most clinically significant aerobic gramnegative bacilli, Staphylococcus spp., Enterococcus spp., Streptococcus agalactiae, and S. pneumoniae.
The VITEK 2 AST Cards are essentially miniaturized versions of the doubling dilution technique for determining the minimum inhibitory concentration (MIC) microdilution methodology.
The bacterial isolate to be tested is diluted to a standardized concentration in 0.45% saline before being used to rehydrate the antimicrobial medium within the card. The VITEK 2 System 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 antibiotic contained on the card.
The provided text describes the acceptance criteria and study for the VITEK® 2 Gram Positive Telithromycin for Streptococcus pneumoniae device. This device is an automated antimicrobial susceptibility test system.
Here's a breakdown of the requested information:
1. A table of acceptance criteria and the reported device performance
| Metric | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Overall Category Agreement | "Acceptable performance" (as defined in the FDA Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA, Issued Feb. 5, 2003). While a specific percentage for acceptance isn't explicitly stated as a numerical threshold, the guidance document would outline typical benchmarks for AST systems. | 99.5% |
| Reproducibility | Acceptable results | Acceptable |
| Quality Control | Acceptable results | Acceptable |
2. Sample size used for the test set and the data provenance
- Sample Size for Test Set: The document mentions "fresh and stock clinical isolates and stock challenge strains." It does not provide a specific number for the sample size of the test set used in the external evaluation.
- Data Provenance: The data was generated through an "external evaluation." The country of origin is not explicitly stated, but bioMérieux, Inc. is based in Hazelwood, MO, USA, and the submission is to the FDA, suggesting the study was likely conducted, or at least overseen, within the US context. The use of "clinical isolates" implies retrospective data, while "stock challenge strains" are laboratory-maintained and can be used prospectively. The exact mix is not detailed.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The document does not specify the number or qualifications of experts used to establish the ground truth.
4. Adjudication method for the test set
The document does not describe any specific adjudication method.
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, a multi-reader multi-case (MRMC) comparative effectiveness study was not done. This device is an automated in vitro diagnostic system for antimicrobial susceptibility testing, not a device intended to assist human readers in image interpretation or diagnosis. Therefore, its performance is compared to a reference method, not against human readers.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Yes, a standalone performance evaluation was done. The VITEK® 2 system is a "Fully Automated Short-Term Incubation Cycle Antimicrobial Susceptibility Device." The study compared the device's performance directly against the CLSI broth microdilution reference method. The VITEK 2 automatically fills, seals, incubates, and reads the cards, generating results without human interpretation of raw growth data.
7. The type of ground truth used
The ground truth used was the CLSI broth microdilution reference method. This is a laboratory-standardized method for determining the minimum inhibitory concentration (MIC) of antibiotics.
8. The sample size for the training set
The document does not provide information about a separate training set or its sample size. The focus is on the performance evaluation of the device as a whole. While such systems are developed using data, the submission predominantly details the validation study for regulatory approval.
9. How the ground truth for the training set was established
The document does not provide information on how the ground truth for a training set was established, as it does not explicitly describe a "training set" in the context of this regulatory submission.
§ 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.”