(84 days)
ETEST® is a quantitative technique for determination of antimicrobial susceptibility of non-fasticious Gram-negative and Gram-positive aerobic bacteria such as Enterobacteriaceae, Pseudomonas, Staphylococcus, and fastidious bacteria, such as anaerobes, N. gonorrhoeae, S. pneumoniae, Streptococcus and Haemophilus species. The system comprises a predefined antibiotic gradient which is used to determine the Minimum Inhibitory Concentration (MIC), in ug/mL, of different antimicrobial agents against microorganisms as tested on agar media using overnight incubation.
Telavancin has been shown to be active against the Gram positive aerobic microorganisms listed below, according to the FDA label for this antimicrobial agent.
Active both in vitro and in clinical infections: Staphylococcus aureus (including methicillin resistant isolates) Enterococcus faecalis (vancomycin susceptible isolates only)
ETEST® is a thin, inert and non-porous plastic strip carrying on one side (A) the MIC reading scale in ug/mL, and on the other side (B) a predefined antibiotic gradient.
When the strip is applied to an inoculated agar surface, the preformed antibiotic gradient immediately transfers into the agar matrix, then forming a stable, continuous and exponential gradient of antibiotic concentrations directly underneath the strip. Bacterial growth becomes visible during incubation, and a symmetrical inhibition ellipse centered along the strip appears. The MIC value is read from the scale in terms of ug/mL at complete inhibition of bacterial growth, where the pointed end of the ellipse intersects the strip.
Here's an analysis of the acceptance criteria and study detailed in the provided document for the ETEST® Telavancin device:
Acceptance Criteria and Device Performance
| Criteria | Reported Device Performance (%) |
|---|---|
| Staphylococcus aureus | |
| Essential Agreement (EA) | 98.4 |
| Category Agreement (CA) | 97.9 |
| Enterococcus faecalis | |
| Essential Agreement (EA) | 91.6 |
| Category Agreement (CA) | 97.6 |
Study Information:
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Sample sizes used for the test set and the data provenance:
The document does not specify the exact sample sizes for Staphylococcus aureus or Enterococcus faecalis isolates used in the test set. It mentions "External evaluations were conducted with fresh and stock clinical isolates, as well as a set of challenge strains." The provenance of the data (country of origin) is not explicitly stated. The nature of the data (retrospective or prospective) is also not explicitly detailed, but the use of "fresh and stock clinical isolates" suggests a mix, potentially with retrospective elements for the stock isolates and prospective elements for the fresh isolates. -
Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
This information is not provided in the document. The ground truth was established by comparing the device's performance to the CLSI M07-A10 January 2015 broth microdilution reference method, which is a standardized laboratory procedure, not typically relying on individual expert judgment for ground truth determination. -
Adjudication method for the test set:
This is not applicable as the ground truth was established by a standardized reference method (CLSI broth microdilution) rather than human adjudication. -
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. The ETEST® Telavancin is an antimicrobial susceptibility test system, not an AI-assisted diagnostic tool for human readers. Its performance is evaluated against a reference laboratory method. -
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
Yes, a standalone performance evaluation was done. The ETEST® Telavancin device's performance was compared directly to the CLSI M07-A10 broth microdilution reference method, without human-in-the-loop assistance influencing the ETEST® results. The ETEST® strip itself is read visually by a laboratory technician to determine the MIC value, which is part of its intended "standalone" use. -
The type of ground truth used:
The ground truth used was a reference laboratory method: the CLSI M07-A10 January 2015 broth microdilution method. This method is considered the gold standard for antimicrobial susceptibility testing. -
The sample size for the training set:
The document does not provide information regarding a separate "training set" or its sample size. For medical devices like AST systems, the development often involves an iterative process of design and internal testing, but the document focuses on the validation against established reference methods, which is typically done on a distinct "test set." -
How the ground truth for the training set was established:
Since no information on a specific "training set" and its sample size is provided, the method for establishing its ground truth is also not described.
§ 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).