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This submission is for Etest Doripenem for MIC determinations across 0.002-32 µg/mL with Gram negative aerobic bacteria such as Enterchacteriaceae, Accretobacer baumanii, Pseudomonas aeraginesa and Gram negative anaerobic bacteria such as Bacteroides aacae, B. fragilis, B.thetaiotaorracron, B. uniformis and B. ulgatus.

Etest is a quantitative technique for determination of antimicrobial susceptibility of both nonfastidious Gram negative and Gram positive aerobic bacteria such as Enterchaceriane, Pseudomnas, Staphylococus and Enteroxous species and fastidious bacteria, such as anaerobes, N. gonombeae, S. preumoniae, Streptoxous and Haemophilus species. The system comprises a predelined 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 using overnight incubation.

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This FDA 510(k) clearance letter pertains to the administrative process of marketing the Etest® Antimicrobial Susceptibility Test for Doripenem, rather than a detailed scientific study report. Therefore, much of the requested information about acceptance criteria and study particulars is not present in this document.

However, based on the context of an antimicrobial susceptibility test and the information provided, we can infer some aspects and acknowledge the limitations:

1. A table of acceptance criteria and the reported device performance

This document does not contain a table of acceptance criteria or specific performance values for the Etest® Doripenem test. Such information would typically be found in the manufacturer's 510(k) submission itself (which this document is a response to), or in scientific publications. However, for a device like this, the acceptance criteria would generally revolve around:

• Essential Agreement (EA) with a reference method: The percentage of MIC values that are within ±1 dilution of the reference method.
• Categorical Agreement (CA) with a reference method: The percentage of isolates where the Etest interpretation (Susceptible, Intermediate, Resistant) matches the reference method's interpretation.
• Minor Errors (mE), Major Errors (ME), and Very Major Errors (VME): These refer to specific types of discordance between the test and reference method, particularly concerning clinical interpretation. The acceptable rates for these errors are usually defined by regulatory bodies (e.g., FDA, CLSI).

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

This information is not available in the provided document. A typical premarket submission for an antimicrobial susceptibility test would involve testing a substantial number of bacterial isolates (e.g., hundreds or even thousands) for each drug-bug combination, often collected from diverse geographical locations. The studies would predominantly be prospective.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

This information is not available in the provided document. For antimicrobial susceptibility testing, the "ground truth" (or reference method) is typically established by laboratory-based, standardized methods using trained microbiologists (e.g., broth microdilution or agar dilution). It's not usually based on expert consensus in the same way as, for example, reading medical images.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

This information is not available in the provided document. Adjudication methods are not typically relevant for establishing the "ground truth" for a microbial susceptibility test; the reference method itself serves as the standard.

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

An MRMC study is not applicable to this type of device. The Etest is a diagnostic test for determining drug susceptibility, not an AI-assisted diagnostic imaging tool.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

The Etest is a manual, phenotypic test strip. It is not an algorithm, nor does it operate "standalone" in the sense of a software algorithm. Its performance is evaluated based on its interpretability by trained laboratory personnel against a recognized reference method.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

The "ground truth" for antimicrobial susceptibility testing is typically established using a standardized reference method, such as:

• Broth Microdilution (BMD): Considered the gold standard for MIC determination.
• Agar Dilution: Another standardized method for MIC determination.

These methods involve precise dilutions of the antimicrobial agent and inoculation with a standardized bacterial suspension.

8. The sample size for the training set

This information is not available in the provided document. The Etest method relies on a pre-defined antibiotic gradient within the strip, not a "training set" in the machine learning sense. However, the manufacturer would have conducted extensive internal development and validation studies to determine the appropriate gradient and how to interpret the ellipse.

9. How the ground truth for the training set was established

As noted above, there isn't a "training set" in the machine learning context for this device. The development of Etest strips generally involves:

• Careful preparation of the antibiotic gradient: Ensuring precise and stable concentrations along the strip.
• Extensive testing against known bacterial strains: Using reference methods (like BMD) to correlate the ellipse formed by the Etest strip with the actual MIC of the drug for those strains. This helps in establishing the interpretive breakpoints for susceptibility, intermediate, and resistance categories.

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