(229 days)
VITEK® 2 AST - Gram Positive Penicillin for Streptococcus pneumoniae is designed for antimicrobial susceptibility testing of Streptococcus pneumoniae. VITEK 2 AST - Gram Positive Penicillin for Streptococcus pneumoniae 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. Penicillin has been shown to be active against most strains of the microorqanism listed below, according to the FDA label for this antimicrobial.
Streptococcus pneumoniae (pneumonia and meningitis)
· 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 gram-negative bacilli, Staphylococcus spp., Enterococcus spp., Streptococcus agalactiae, and S. pneumoniae.
The VITEK 2 AST Cards are essentially miniaturized versons 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 with 0.45 - 0.5% 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, sealing and loading operation. The VITEK 2 Systems monitor the growth of each well in the card over a defined period of time. At the completion cycle, a report is generated that contains the MC value along with the interpretive category result for each antibiotic contained on the card.
Here's a breakdown of the acceptance criteria and study details for the VITEK® 2 AST - Gram Positive Penicillin for Streptococcus pneumoniae, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Acceptance Criteria (from "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA, issued August 28, 2009") | Reported Device Performance |
|---|---|---|
| Category Agreement (CA) | Not explicitly stated as a numerical threshold in the provided text, but implied as "acceptable performance" | 92.3% for pneumonia breakpoints |
| 96.9% for meningitis breakpoints | ||
| Reproducibility | Not explicitly stated as a numerical threshold | Demonstrated acceptable results |
| Quality Control | Not explicitly stated as a numerical threshold | Demonstrated acceptable results |
Note: The specific numerical acceptance criteria for Category Agreement, Reproducibility, and Quality Control from the "Class II Special Controls Guidance Document" are not fully detailed in the provided text. The document only references that the study was designed to confirm acceptability based on this guidance.
2. Sample Size and Data Provenance for the Test Set
- Sample Size for Test Set: An "external evaluation was conducted with fresh and stock clinical isolates and stock challenge strains." The exact number of isolates used is not specified in the provided text.
- Data Provenance: The text does not explicitly state the country of origin. It indicates the data came from "external evaluations" and used "fresh and stock clinical isolates and stock challenge strains." This suggests a combination of retrospective (stock isolates) and prospective (fresh clinical isolates) data.
3. Number of Experts and Qualifications for Ground Truth of the Test Set
- The text does not provide any information about the number of experts used or their qualifications to establish the ground truth for the test set.
4. Adjudication Method for the Test Set
- The text does not provide any information about the adjudication method used for the test set.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
- No, an MRMC comparative effectiveness study was not done as described in this document. The study compares the device's performance to a reference method (CLSI broth microdilution), not human readers with and without AI assistance.
6. Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study
- Yes, a standalone study was performed. The VITEK® 2 AST system, which is an automated system, demonstrates performance by comparing its results directly with the CLSI broth microdilution reference method. The text states: "VITEK 2 Gram Positive Penicillin for Streptococcus pneumoniae demonstrated substantially equivalent performance when compared with the CLSI broth microdilution reference method." This indicates the algorithm's performance without human intervention in susceptibility determination.
7. Type of Ground Truth Used
- The ground truth used was the CLSI broth microdilution reference method. This is considered the gold standard for antimicrobial susceptibility testing.
8. Sample Size for the Training Set
- The provided text does not specify the sample size for the training set. It only mentions the "external evaluation" for performance assessment.
9. How Ground Truth for the Training Set Was Established
- The provided text does not specify how the ground truth for the training set was established. It only refers to the CLSI broth microdilution reference method for the performance evaluation.
§ 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.”