(53 days)
The VITEK® 2 Antimicrobiat Susceptibility Test (AST) is intended to be used with the The VITEN 2 Antimorobial Oacoopinalitative or qualitative susceptibility testing of isolated colonies for the most clinically significant aerobic gram-negative bacilli, Staphylococus sp., Enterococus sp., Streptococus agalactiae, and S. pneumoniae. VITEK® 2 Gram Negative Er susceptibility testing of Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Susceptiblity tooking of Enterobacter aerogenes, Enterobacter cloacae, Klebsiella oxytoca Citrobacter Roson, EnteroBactor Col. Morganella morganii, Proteus mirabilis, Proteus (axcluding EODE producing carens) It is intended for use with the VITEK 2 System as a valgaris, and Gorratia merosestion of in vitro susceptibility to antimicrobial agents.
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 automatically fills, seals and places the card into the incubator/reader. 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.
Here's an analysis of the provided text regarding the acceptance criteria and study for the VITEK® 2 Gram Negative Ertapenem device:
1. Table of Acceptance Criteria and Reported Device Performance:
The document primarily focuses on a single key performance metric for demonstrating substantial equivalence. The "acceptance criteria" can be inferred from the FDA guidance document referenced.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Overall Category Agreement (with NCCLS reference method) | "Substantially equivalent performance" (as defined by FDA guidance, typically >90% for AST devices) | 98.8% |
2. Sample Size Used for the Test Set and Data Provenance:
- Test Set Sample Size: Not explicitly stated as a total number. The text mentions "fresh and stock clinical isolates and stock challenge strains." This suggests a mixed collection but no specific count.
- Data Provenance: The external evaluation was conducted. The country of origin is not specified, but the submission is from bioMérieux, Inc. in Hazelwood, MO, USA. The data includes both "fresh and stock clinical isolates" (implying retrospective clinical samples) and "stock challenge strains" (likely laboratory-prepared strains).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications:
Not applicable. The ground truth was established by a laboratory reference method, not by human expert interpretation of images or clinical data.
4. Adjudication Method for the Test Set:
Not applicable. The study compares the device's output (MIC values and interpretive categories) directly against a laboratory reference method (NCCLS agar dilution method). There is no "adjudication" in the sense of resolving conflicting human interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done:
No, an MRMC comparative effectiveness study was not done. This type of study is typically performed for diagnostic imaging devices where human readers interpret results, and the AI's impact on their performance is being assessed. This device is an automated antimicrobial susceptibility test system.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done:
Yes, the study described is a standalone performance evaluation. The VITEK® 2 system, which contains the Ertapenem test, automatically processes the samples, determines MIC values, and generates interpretive categories. This performance is then compared directly to the NCCLS reference method without human intervention during the test result generation phase.
7. The Type of Ground Truth Used:
The ground truth used was the NCCLS reference agar dilution method. This is a well-established and accepted laboratory method for determining antimicrobial susceptibility.
8. The Sample Size for the Training Set:
The document does not provide information on the sample size used for the training set. This is common for older 510(k) submissions, particularly for devices that may have built upon previous versions or established methodologies where the "training" (if any, in a machine learning sense) might have occurred much earlier in the product's development cycle or be related to the underlying biological principles rather than a machine learning algorithm.
9. How the Ground Truth for the Training Set Was Established:
As the training set information is not provided, the method for establishing its ground truth is also not mentioned. However, it's highly probable that any internal development or "training" would also have relied on established laboratory reference methods like the NCCLS agar dilution 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.”