(209 days)
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 either visually or with MicroScan® WalkAway instrument.
This particular submission is for the evaluation of antimicrobial agent penicillin on the MicroScan® MICroSTREP plus® Panel utilizing the updated Streptococcus pneumoniae meningitis interpretative criteria (S ≤ 0.06, R ≥ 0.12) and non-meningitis interpretative criteria (S ≤ 2, I = 4, R ≥ 8).
The organisms which may be used for Penicillin susceptibility testing in this panel are:
Streptococcus pneumoniae
Streptococci (Groups A, C, G, H, L and M)
Streptococcus agalactiae
Viridans Streptococci
MicroScan MICroSTREP plus® Panels are designed for use in determining quantitative and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of rapidly growing 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 or with the MicroScan WalkAway instrument according to the Package Insert.
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 water, buffer, or minute concentrations of broth to concentrations bridging the range of clinical interest. Panels are rehydrated with 115ul Mueller-Hinton broth supplemented with 2-5% lysed horse blood (LHB) and buffered with 50 mM HEPES, after inoculation 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 read by determining the lowest antimicrobial concentration showing inhibition of growth.
Here's a breakdown of the acceptance criteria and the study details for the MicroScan® MICroSTREP plus® Panels with Penicillin, based on the provided document:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria | Reported Device Performance (Penicillin) |
|---|---|
| Overall Essential Agreement (EA) with CLSI frozen Reference Panel | 92.5% |
Note: The document only explicitly mentions an "overall Essential Agreement" without stating a minimum threshold. However, this level of detail is typical for 510(k) summaries where the criteria might be implied by relevant guidance documents (e.g., FDA's "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems"). The 92.5% Essential Agreement is stated as "acceptable performance."
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: The document refers to "Streptococcus pneumoniae data from the previously cleared Penicillin external evaluations (K062773 and K020626)" and "Challenge strains." However, specific numerical sample sizes for these test sets are not provided in the given text.
- Data Provenance: The document does not explicitly state the country of origin for the data or whether it was retrospective or prospective. It refers to "external evaluations," suggesting that the data likely came from clinical or laboratory studies outside of the direct manufacturing site.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications
This information is not provided in the document. The ground truth for the test set was established using a "CLSI frozen Reference panel" and "Expected Results determined prior to the evaluations." This implies a standardized laboratory reference method, but not a panel of human experts in the typical clinical sense.
4. Adjudication Method for the Test Set
This information is not applicable or not provided in the document. The comparison was made against a "CLSI frozen Reference panel" and "Expected Results," which are objective laboratory standards, not subjective assessments requiring adjudication by multiple readers.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC comparative effectiveness study involving human readers is not described in this document. The device is for determining antimicrobial susceptibility, which is a quantitative/qualitative laboratory test, not a diagnostic interpretation task that typically involves multiple human readers.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
Yes, a standalone performance evaluation was done. The MicroScan® MICroSTREP plus® Panel's performance was compared to a "CLSI frozen Reference panel" and "Expected Results." This is an assessment of the device's inherent ability to determine MIC values without direct human intervention in the interpretive phase (though humans operate the device). The device can be read "visually or with the MicroScan WalkAway instrument."
7. The Type of Ground Truth Used
The ground truth used was based on:
* A CLSI frozen Reference panel: This refers to a standardized laboratory reference method (Clinical and Laboratory Standards Institute guidelines) which is considered the gold standard for antimicrobial susceptibility testing.
* Expected Results: These are pre-determined outcomes for the challenge strains, likely established through the CLSI reference method.
8. The Sample Size for the Training Set
The document refers to "previously cleared Penicillin external evaluations (K062773 and K020626)." While these prior submissions would have involved training data or development data, the specific sample size for the training set for this particular modification is not provided in the given text. The current submission focuses on evaluating the updated interpretive criteria on existing data.
9. How the Ground Truth for the Training Set Was Established
Similar to point 8, the specific methodology for establishing ground truth for the training set used in previous submissions (K062773 and K020626) is not detailed in this document. It can be inferred that it would also have followed CLSI guidelines and reference methods, given the nature of the device and the comparison in the current submission.
§ 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).