(135 days)
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 antimicrobial ceftazidime/avibactam at concentrations of 0.25/4 to 64/4 ug/mL to the test panel.
The gram-negative organisms which may be used for ceftazidime/avibactam susceptibility testing in this panel are:
Citrobacter freundii complex, Citrobacter koseri, Enterobacter cloacae, Escherichia coli, Klebsiella oxytoca. Klebsiella pneumoniae, Morganii, Proteus mirabilis. Pseudomonas aeruginosa. Providencia rettgeri, Providencia stuartii, and Serratia marcescens
MicroScan Dried Gram-Neqative 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 aerobic 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.
This document describes the validation of Beckman Coulter's MicroScan Dried Gram-Negative MIC/Combo Panels with Ceftazidime/Avibactam for determining antimicrobial susceptibility.
Here's a breakdown of the acceptance criteria and study details based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
The document uses "Essential Agreement" as the primary performance metric. While specific numerical acceptance criteria (e.g., "must be at least X%") are not explicitly stated as a separate line item, the reported values are presented as demonstrating "acceptable performance" compared to an FDA guidance document.
| Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|
| Overall Essential Agreement (Enterobacteriaceae) required to be acceptable per FDA guidance | 95% |
| Overall Essential Agreement (Pseudomonas aeruginosa) required to be acceptable per FDA guidance | 96.3% |
| Reproducibility and Precision with different inoculum methods (Turbidity or Prompt™) and instruments (autoSCAN-4 or WalkAway) | Acceptable |
| Quality Control testing | Acceptable |
Note: The document states the performance was compared with CLSI frozen Reference Panel, as defined in an FDA guidance document. This implies the acceptable thresholds are those outlined in that guidance, though they are not explicitly listed in this summary.
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Test Set): Not explicitly stated with a single numerical value. The "external evaluations" were conducted with "fresh and stock Efficacy isolates and stock Challenge strains." However, the number of these isolates is not provided in this summary.
- Data Provenance: Not explicitly stated. The document refers to "external evaluations," but does not specify the country of origin of the data or whether the study was retrospective or prospective. Given the context of a 510(k) submission, it's highly likely to be prospective clinical and/or simulated data, but this is not confirmed.
3. Number of Experts Used to Establish Ground Truth and Qualifications
This information is not provided in the document. The ground truth is established by a "CLSI frozen Reference panel," which is a laboratory standard rather than human expert consensus.
4. Adjudication Method for the Test Set
This information is not applicable as the ground truth is established by a "CLSI frozen Reference panel" and not through human experts requiring adjudication.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
A multi-reader multi-case (MRMC) comparative effectiveness study was not conducted. This is a study for an in vitro diagnostic device, not an imaging device requiring human reader interpretation. The device is designed to determine antimicrobial susceptibility, which is a direct measurement against a reference, not an interpretation task where human readers would improve with AI assistance.
6. Standalone Performance
Yes, standalone performance was done. The study directly compares the MicroScan Dried Gram-Negative MIC/Combo Panels' performance against a CLSI frozen Reference panel. This is effectively the algorithm/device's performance without human-in-the-loop assistance for the susceptibility reading itself, although humans operate the device and interpret the results against clinical breakpoints. The "Essential Agreement" values represent this standalone performance. The document states panels are "read either visually or with MicroScan instrumentation," indicating the device itself generates the MIC values.
7. Type of Ground Truth Used
The ground truth used was a CLSI frozen Reference Panel. This is a laboratory standard for antimicrobial susceptibility testing, considered the definitive method against which new methods are compared.
8. Sample Size for the Training Set
The document does not mention a training set or its sample size. This type of device (an antimicrobial susceptibility test panel) is not typically "trained" like a machine learning algorithm for image analysis. Instead, its performance is validated through comparison to a well-established reference method, ensuring it consistently and accurately measures antimicrobial susceptibility.
9. How the Ground Truth for the Training Set Was Established
As there is no mention of a training set, this information is not applicable.
§ 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).