Search Results

The MicroScan® MICroSTREP plus™ Panel is used to determine quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of aerobic streptococci, including Streptococcus pneumoniae. After inoculation, panels are incubated for 20 - 24 hours at 35°C +/- 1°C in a non-CO2 incubator, and read visually according to the Package Insert.

To determine bacterial antimicrobial agent susceptibility

This particular submission is for the addition of the antimicrobial Azithromycin at concentrations of 0.12 to 4 mcg/ml to the test panel

The organisms which may be used for Azithromycin susceptibility testing in this panel are:

Streptococcus pneumoniae
Streptococcus pyogenes
Streptococcus agalactiae
streptococci (Groups C. F. G)
viridans group streptococci

The MicroScan® MICroSTREP plus™ Panel is used to determine quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of aerobic streptococci, including Streptococcus pneumoniae. After inoculation, panels are incubated for 20 - 24 hours at 35°C +/- 1°C in a non-CO2 incubator, and read visually according to the Package Insert.

The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test. Various antimicrobial agents are diluted in water, buffer or minute concentrations of broth to concentrations bridging the range of clinical interest. Panels are rehydrated with 115 ul Mueller-Hinton broth supplemented with 2-5% lysed horse blood (LHB) and buffered with 50 mM HEPES, after inoculation of the broth with a standardized suspension of the organism in saline. After incubation in a non-CO2 incubator for 20-24 hours, the minimum inhibitory concentration (MIC) for the test organism is manually read by observing the lowest antimicrobial concentration showing inhibition of growth.

Here's an analysis of the provided text, outlining the acceptance criteria and study details for the MicroScan® MICroSTREP plus™ Panel for Azithromycin susceptibility testing:

Acceptance Criteria and Device Performance Study

1. Table of Acceptance Criteria and Reported Device Performance

Note: The document explicitly states the acceptance criteria for Essential Agreement as "acceptable performance," and then provides the 99.3% result. For reproducibility and quality control, it simply states "acceptable reproducibility and precision" and "acceptable results," implying these met their internal criteria without providing a specific quantitative benchmark in the summarized text.

2. Sample Size Used for the Test Set and Data Provenance

• Test Set Sample Size: The document indicates the external evaluation was conducted with "fresh and stock Efficacy isolates and stock Challenge strains" for streptococcal isolates. However, a specific number for the sample size (number of isolates/strains) is not provided in the summary.
• Data Provenance: The study was an "external evaluation," suggesting it was conducted by an entity separate from the manufacturer. The document doesn't specify the country of origin of the data, but the context is a submission to the FDA in the USA. It's unclear whether the data was retrospective or prospective, though "fresh and stock isolates" suggest a mix, potentially with fresh isolates being prospective and stock isolates being retrospective.

3. Number of Experts Used to Establish Ground Truth and Their Qualifications

The document does not provide any information about the number of experts used or their qualifications to establish the ground truth.

4. Adjudication Method for the Test Set

The document does not provide any information about an adjudication method. The comparison was made against an "NCCLS frozen Reference panel."

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

An MRMC comparative effectiveness study was not performed or reported. The study focuses on the standalone performance of the device against a reference method, not the impact of AI assistance on human readers.

6. Standalone Performance Study

Yes, a standalone study was done. The entire premise of the submission is to demonstrate the performance of the MicroScan® MICroSTREP plus™ Panel (an algorithm/device) in determining antimicrobial susceptibility. Its performance (Essential Agreement) was compared directly to an "NCCLS frozen Reference panel."

7. Type of Ground Truth Used

The ground truth used was an NCCLS frozen Reference Panel. This panel serves as the established gold standard for determining antimicrobial susceptibility in this context. While not explicitly stated as "expert consensus" or "pathology," a reference panel developed by organizations like NCCLS (now CLSI) inherently represents a consensus on accurate susceptibility determination methods.

8. Sample Size for the Training Set

The document does not provide any information about a training set sample size. This type of device relies on established biological and chemical reactions interpreted via a defined protocol, rather than a machine learning model that typically requires a large training set.

9. How the Ground Truth for the Training Set Was Established

As no training set is mentioned in the context of machine learning, the question of how its ground truth was established is not applicable. The device's operational principles are based on known antimicrobial agent concentrations and visual interpretation of bacterial growth inhibition against an established reference method (NCCLS frozen Reference Panel) for validation.

Ask a specific question about this device