MICROSCAN DRIED GRAM -NEGATIVE MIC/COMBO PANELS WITH TIGECYCLINE (0.015- 32 MCG/ML)

• K Number: K083262
• Device Name: MICROSCAN DRIED GRAM -NEGATIVE MIC/COMBO PANELS WITH TIGECYCLINE (0.015- 32 MCG/ML)
• Manufacturer: SIEMENS HEALTHCARE DIAGNOSTICS
• Date Cleared: 2009-02-18 ( 105 days)
• Product Code: LTT , JWY , LRG , LTW
• Regulation Number: 866.1640
• Type: Traditional
• Panel: MI
• Reference & Predicate Devices: K020353

Intended Use

The MicroScan® Dried Gram-Negative MIC/Combo Panel is used to determine quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing aerobic and facultative anaerobic gram-negative bacilli. After inoculation, panels are incubated for 16 - 20 hours at 35°C +/- 1°C in a non-CO2 incubator, and read either visually or with MicroScan instrumentation, according to the Package Insert.

This particular submission is for the addition of the antimicrobial Tigecycline at concentrations of 0.015 to 32 mcg/ml to the test panel.

The gram-negative organisms which may be used for Tigecycline susceptibility testing in this panel are:

Citrobacter freundii Enterobacter cloacae Escherichia coli Klebsiella oxytoca Klebsiella pneumoniae

Device Description

MicroScan Dried Gram-Negative MIC/Combo Panels are designed for use in determining quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing acrobic and facultative anaerobic gram-negative bacilli.

The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test that have been diluted in broth and dehydrated. Various antimicrobial agents are diluted in broth to concentrations bridging the range of clinical interest. Panels are rehydrated with water after inoculation with a standardized suspension of the organism. After incubation in a non-CO2 incubator for 16-20 hours, the minimum inhibitory concentration (MIC) for the test organism is read by determining the lowest antimicrobial concentration showing inhibition of growth.

AI/ML Overview

Here's an analysis of the provided text, outlining the acceptance criteria and study details for the MicroScan Dried Gram-Negative MIC/Combo Panels with Tigecycline:

Acceptance Criteria and Reported Device Performance

Acceptance Criteria Category	Specific Criteria	Reported Device Performance
Overall Agreement	Essential Agreement	99.0% for Tigecycline
Reproducibility	Acceptable Inoculum Reproducibility (Turbidity)	Demonstrated acceptable reproducibility (Tigecycline)
Reproducibility	Acceptable Inoculum Reproducibility (Prompt™)	Demonstrated acceptable reproducibility (Tigecycline)
Reproducibility	Acceptable Instrument Reproducibility (autoSCAN-40)	Demonstrated acceptable reproducibility (Tigecycline)
Reproducibility	Acceptable Instrument Reproducibility (WalkAway®)	Demonstrated acceptable reproducibility (Tigecycline)
Quality Control	Acceptable QC results	Demonstrated acceptable results (Tigecycline)

Study Details

1. Sample Size Used for the Test Set and Data Provenance:

   • Sample Size: Not explicitly stated as a number of isolates or tests. The external evaluation was conducted with "fresh and stock Efficacy isolates and stock Challenge strains."
   • Data Provenance: Not specified, but the use of "external evaluation" suggests data was collected from sites outside the manufacturer's internal testing facilities. The country of origin is not mentioned. The data is retrospective, as "stock Efficacy isolates and stock Challenge strains" were used.

2. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:

   • Number of Experts: Not specified.
   • Qualifications of Experts: Not specified.

3. Adjudication Method for the Test Set:

   • Adjudication Method: Not explicitly stated. For the "Challenge strains," their performance was "compared to Expected Results determined prior to the evaluation," suggesting a pre-defined set of known results rather than a real-time adjudication process by experts. For "Efficacy isolates," the comparison was against a CLSI frozen Reference Panel, again indicating a reference standard rather than expert consensus adjudication of each case.

4. 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, an MRMC study was not done. This device is an automated antimicrobial susceptibility test (AST) panel, not an AI-assisted diagnostic device that would involve human readers interpreting images or data with and without AI assistance. The performance is compared to a reference standard (CLSI frozen panel), not human interpretation.

5. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was done:

   • Yes, a standalone study was done. The device's performance (MicroScan Dried Gram-Negative MIC/Combo Panel) was evaluated solely based on its ability to determine MICs compared to a "CLSI frozen Reference Panel." The stated "99.0% Essential Agreement" is a direct measure of the device's accuracy against this objective reference standard. Human intervention described is limited to inoculation and reading (visually or with MicroScan instrumentation), but the performance evaluation is of the test system itself against a known reference.

6. The Type of Ground Truth Used:

   • Reference Standard (CLSI frozen Reference Panel) and Expected Results: The primary ground truth for efficacy isolates was the "CLSI frozen Reference Panel." For challenge strains, "Expected Results determined prior to the evaluation" served as the ground truth. This indicates a highly standardized and objective reference method for determining antimicrobial susceptibility.

7. The Sample Size for the Training Set:

   • Not Applicable. This submission describes the validation of an antimicrobial susceptibility test (AST) panel following a traditional broth dilution method, not an AI/ML-based algorithm that typically requires a discrete "training set." The panel is a diagnostic test kit, and its "training" is inherent in its design and manufacturing process, optimized through extensive research and development for antimicrobial properties and concentrations, not through machine learning on a dataset.

8. How the Ground Truth for the Training Set Was Established:

   • Not Applicable. As noted above, there isn't a "training set" in the context of an AI/ML algorithm. The design and validation of the MIC panels rely on established microbiology principles, standardized broth dilution methods (CLSI guidelines), and quality control procedures, rather than a machine learning training process with a ground truth dataset.

Regulation Number and Section

§ 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).