← Product Code [LRG](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LRG) · K062927 # MICROSCAN MICROSTREP PLUS PANEL AMPICILLIN (0.013 - 16 MCG/ML) (K062927) _Dade Behring, Inc. · LRG · Oct 12, 2006 · Microbiology · SESE_ **Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LRG/K062927 ## Device Facts - **Applicant:** Dade Behring, Inc. - **Product Code:** [LRG](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LRG.md) - **Decision Date:** Oct 12, 2006 - **Decision:** SESE - **Submission Type:** Traditional - **Regulation:** 21 CFR 866.1640 - **Device Class:** Class 2 - **Review Panel:** Microbiology ## Indications for Use To determine bacterial antimicrobial agent susceptibility ## Device Story MicroScan® MICroSTREP plus® Panel is a 96-well plastic dish containing dehydrated antimicrobial agents. Panels are rehydrated with Mueller-Hinton broth supplemented with 2-5% lysed horse blood and inoculated with standardized bacterial suspensions (approx. 5 × 10⁵ CFU/mL). After 20-24 hours of incubation at 35°C, growth is assessed to determine the Minimum Inhibitory Concentration (MIC). The device supports both manual reading and automated reading via the MicroScan® WalkAway System, which utilizes optics light detection to measure growth. The automated system provides quantitative and qualitative susceptibility results, assisting clinicians in selecting appropriate antibiotic therapy for aerobic streptococci infections. ## Clinical Evidence Bench testing only. Reproducibility study (10 isolates, 3 sites, 3 days) and challenge study (70 isolates) compared manual vs. automated reading. Both methods demonstrated >95% reproducibility and >94% essential agreement (EA) with reference broth dilution methods. No very major or major discrepancies were observed. QC performance using S. pneumoniae ATCC 49619 confirmed the accuracy of the automated reading parameters. ## Technological Characteristics Miniaturized broth dilution susceptibility test panel. Reagents: Mueller-Hinton broth, 2-5% lysed horse blood, 50 mM HEPES buffer. Incubation: 20-24 hours at 35°C +/- 1°C. Readout: Manual visual observation or automated optical reading via MicroScan WalkAway instrument. Connectivity: Integrated with WalkAway instrument system. ## Regulatory 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. ## Predicate Devices - MicroScan® MICroSTREP plus® Panel ([K062927](/device/K062927.md)) ## Submission Summary (Full Text) > This content was OCRed from public FDA records by [Innolitics](https://innolitics.com). If you use, quote, summarize, crawl, or train on this content, cite Innolitics at https://innolitics.com. > > Innolitics is a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices, including [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/). {0} Page 1 of 7 # 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY TEMPLATE A. 510(k) Number: K062927 B. Purpose for Submission: To add the option for automated reading of Ampicillin at 0.03 – 16 µg/mL to the MICroSTREP plus® Panel on the MicroScan® WalkAway System C. Measurand: Ampicillin at 0.03 – 16 µg/mL D. Type of Test: Quantitative and Qualitative growth based detection algorithm using optics light detection E. Applicant: Dade Behring Inc, MicroScan® F. Proprietary and Established Names: MicroScan® MICroSTREP plus® Panel – Ampicillin at 0.03 – 16 µg/mL G. Regulatory Information: 1. Regulation section: 21 CFR 866.1640 – Antimicrobial Susceptibility Test Powder 2. Classification: Class II 3. Product Code: LRG – Instrument for Auto Reader & Interpretation of Overnight Antimicrobial Susceptibility System LTT – Panels, Test, Susceptibility, Antimicrobial 4. Panel: 83 Microbiology H. Intended Use: 1. Intended use(s): Ampicillin at 0.03 – 16 µg/mL is for use with MICroSTREP plus® Panels MICroSTREP plus® Panels are designed for use in determining quantitative {1} Page 2 of 7 and/or qualitative antimicrobial agent susceptibility of colonies grown on solid media of aerobic streptococci, including *Streptococcus pneumoniae*. 2. **Indication(s) for use:** This submission is for adding the option for automated reading of the antibiotic Ampicillin at concentrations of 0.03 – 16 µg/mL to MICroSTREP *plus®* Panels on the MicroScan® WalkAway System for testing aerobic streptococci other than *Streptococcus pneumoniae*. 3. **Special condition for use statement(s):** - Prescription Use Only - Turbidity method of inoculum preparation only - Intended for aerobic streptococci other than *Streptococcus pneumoniae* The current absence of data on Beta-hemolytic Streptococci strains resistant to Ampicillin precludes defining any results other than “Susceptible”. Strains yielding results suggestive of a non-susceptible category should be submitted to a reference laboratory for further testing. 4. **Special instrument Requirements:** Not Applicable I. **Device Description:** The MicroScan® MICroSTREP *plus®* Panel is a 96-well plastic dish which contains microdilutions of each antimicrobic in various concentrations dried in aqueous solutions. The panel is rehydrated and inoculated at the same time with a Mueller-Hinton broth supplemented with lysed horse blood (2 – 5%). The target inoculum concentration for each well should be approximately 5 × 10⁵ colony forming units (CFU)/mL. Panels are incubated in a 35°C non-CO₂ incubator for 20-24 hours. After incubation, the panels are read manually for growth. Additionally, panels may be incubated in and read by a MicroScan® WalkAway instrument. Each panel contains a “growth” but it does not contain a “no growth” control well. J. **Substantial Equivalence Information:** 1. **Predicate device name(s):** MICroSTREP *plus®* 2. **Predicate K number(s):** K021037 3. **Comparison with predicate:** | Similarities | | | | --- | --- | --- | | Item | Device | Predicate | | Intended use | Determination of susceptibility to antimicrobics with aerobic streptococci other than *Streptococcus pneumoniae* | Same | {2} | Isolates | For use with aerobic streptococci other than Streptococcus pneumoniae isolated colonies from culture | Same | | --- | --- | --- | | Results | Quantitative with qualitative interpretations | Same | | Incubation | 20 – 24 hours | Same | | Panels | Ampicillin dried in aqueous solution | Same | | Differences | | | | Item | Device | Predicate | | Technology | Growth based using algorithm with optics light detection | Growth based | | Reading | Overnight method Manual or automated | Overnight method Manual read only | | Instrument | MicroScan® WalkAway System or Microdilution viewer | Microdilution viewer | # K. Standard/Guidance Document Referenced (if applicable): "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA"; CLSI M7 (M100-S16) "Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard." # L. Test Principle: The antimicrobial susceptibility tests are miniaturizations of the broth dilution susceptibility test that have been diluted in water 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 $115~\mu \mathrm{L}$ Mueller-Hinton broth supplemented with $2 - 5\%$ lysed horse blood (LHB), after inoculation of the broth with a standardized suspension of the organism. The target inoculum concentration for each well should be approximately $5\times 10^{5}$ colony forming units (CFU)/mL. After incubation in a non- $\mathrm{CO}_{2}$ incubator for 20-24 hours, the minimum inhibitory concentration (MIC) for the test organisms is determined by observing the lowest antimicrobial concentration showing inhibition of growth. Panels can be read manually using indirect light or the panels can be read on the MicroScan® WalkAway instrument using optics light detection. # M. Performance Characteristics (if/when applicable): This submission is for the AST Panel only. The ID System was not reviewed. The Reproducibility studies, QC performance data, and Challenge isolates evaluated by the manual and automated reading methods are contained in this submission to demonstrate that there is no difference between manual reading and automated reading {3} Page 4 of 7 in the MicroScan® WalkAway System. The clinical efficacy performance was previously established using the manual read method and was therefore not required for this submission. Ampicillin was tested in doubling dilutions ranging from 0.015 – 16 µg/mL. Clearance is requested for 0.03 – 16 µg/mL on the MICroStrep plus panel. Challenge and Reproducibility data were presented for both the dilutions tested and the dilutions requested. 1. Analytical performance: a. Precision/Reproducibility: Reproducibility was demonstrated using 10 streptococcal isolates tested at 3 sites on 3 separate days in triplicate. The study included testing on the MicroScan® WalkAway System with automated reading at 20-24 hours, and manual readings at 20-24 hours incubation. The automated reading method produced a slight trend for more susceptible results, if only by one dilution, when the data is mapped to the dilutions requested (0.03 – 16 µg/mL). This trend was driven primarily by one S. pneumoniae (at Sites 1 and 2) and one Viridans streptococci (at Site 1), that produced off-scale results. No trending was observed when the data was mapped to all dilutions tested (0.015—16 µg/mL). Both reading methods demonstrated >95% reproducibility. b. Linearity/assay reportable range: Not applicable c. Traceability, Stability, Expected values (controls, calibrators, or method): The recommended QC isolate S. pneumoniae ATCC 49619 was tested a sufficient number of times with acceptable results on all testing days with the reference method. Quality control results demonstrated the ability of the different reading parameters (manual and instrument) to produce acceptable results. The following table provides the frequency of results in each concentration with the expected range stated. Both reading methods produced the same mode. {4} Page 5 of 7 | Organism | Concentration μg/mL | Reference results | MicroScan® WalkAway results | | | --- | --- | --- | --- | --- | | | | | Manual Overnight | Instrument Overnight | | S. pneumoniae ATCC 49619 Expected range 0.06 – 0.25 μg/mL | <=0.03 | | | 1 | | | 0.06 | 26 | 15 | 18 | | | 0.12 | 36 | 53 | 48 | | | 0.25 | | | | | | 0.5 | | | 1 | | | 1 | | | | | | 2 | | | | Inoculum density control: A turbidity meter, which was verified each day of testing, was used for the turbidity inoculation method. Colony counts were performed weekly, on the ATCC S. pneumoniae with all results in the expected range of approximately $5 \times 10^{5}$. No trending was observed. d. Detection limit: Not applicable e. Analytical specificity: Not applicable f. Assay cut-off: Not applicable 2. Comparison studies: a. Method comparison with predicate device: Clinical efficacy testing with manual result reading was conducted in the previous submission (K021037). In this submission, Challenge isolates were evaluated by the manual and automated reading methods to demonstrate that there is no difference between manual reading and instrument reading on the MicroScan® WalkAway System. There were 70 challenge isolates including 53 S. pneumoniae CDC Challenge Set strains, tested at one site and compared to the reference broth dilution result. A comparison was done with readings on the instrument after 20 hours incubation, and also read manually when incubated for 20-24 hours. Challenge data was provided for all dilutions tested $(0.015 - 16\ \mu\mathrm{g/mL})$, but clearance was requested for 10 dilutions $(0.03 - 16\ \mu\mathrm{g/mL})$. Because ampicillin is intended for testing *Streptococcus* species other than *S. pneumoniae*, the 53 *S. pneumoniae* results were excluded from {5} Page 6 of 7 the error calculations. Performance by the automated reading method was acceptable with no differences or trends. The recommended CLSI reference method was followed with the exception of the use of a small amount (0.1%) of Pluronic (a wetting agent) in the final inoculum. A validation of the use of Pluronic in the frozen reference panel was conducted. QC was also performed with no difference apparent in the results. Read method comparison of *Streptococcus species* other than *S. pneumoniae* and *Ampicillin* | | EA Tot | EA N | EA % | Eval EA Tot | Eval EA N | Eval EA % | #R | min | maj | vmj | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Challenge Manual | 70 | 66 | 94.3 | 57 | 54 | 94.7 | 1 | 0 | 0 | 0 | | Challenge Automated | 70 | 66 | 94.3 | 56 | 53 | 94.6 | 1 | 0 | 0 | 0 | EA-Essential Agreement R-resistant isolates maj-major discrepancies vmj-very major discrepancies min- minor discrepancies Essential agreement (EA) is when the Microscan® MICroSTREP plus® panels agree with the reference test panel results exactly or within one doubling dilution of the reference method. Evaluable (Eval) are results that are within the test range and on scale. Automated reading results were the same as the manual reading results. The slight trending observed in the Reproducibility Study with the automated reading method for a more susceptible result was not detected. There were no vmj, no maj errors, and 1 minor error was generated by both reading methods. The overall EA% of 94.3% and Eval EA% of 94.7% for the manual read and overall EA% of 94.3% and Eval EA% of 94.6% for the automated reading were both very good. The test device had a growth rate of >95% for both the manual reading and the automated reading methods. The comparison of the reading methods demonstrates that the manual reading method and the automated reading on the MicroScan® WalkAway System are no different. The efficacy data performed with the manual reading method would therefore be expected to have no differences. The performance data currently documented in the package insert will not change. b. Matrix comparison: Not applicable {6} Page 7 of 7 3. Clinical studies: a. Clinical sensitivity: Not applicable b. Clinical specificity: Not applicable c. Other clinical supportive data (when a and b are not applicable): Not applicable 4. Clinical cut-off: Not applicable 5. Expected values/Reference range: | Interpretive Criteria | S | I | R | | --- | --- | --- | --- | | Beta hemolytic Streptococci | <=0.25 | * | * | | Viridans Streptococci | <=0.25 | 0.5—4 | >=8 | The expected value range, interpretive criteria and QC are included in the package insert. *The current absence of data on Beta-hemolytic Streptococci strains resistant to Ampicillin precludes defining any results other than "Susceptible". Strains yielding results suggestive of a non-susceptible category should be submitted to a reference laboratory for further testing. N. Proposed Labeling: The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10. O. Conclusion: The submitted information in this premarket notification is complete and supports a substantial equivalence decision. --- **Source:** [https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LRG/K062927](https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LRG/K062927) **Published by [Innolitics](https://innolitics.com)** — a medical-device software consultancy. We help companies design, build, and clear FDA-regulated software and AI/ML devices. If you're preparing [a 510(k)](https://innolitics.com/services/510ks/), [a De Novo](https://innolitics.com/services/regulatory/), [a SaMD](https://innolitics.com/services/end-to-end-samd/), [an AI/ML medical device](https://innolitics.com/services/medical-imaging-ai-development/), or [an FDA regulatory strategy](https://innolitics.com/services/regulatory/), [get in touch](https://innolitics.com/contact). **Cite:** Innolitics at https://innolitics.com