← Product Code [LON](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON) · K032399 # VITEK 2 GRAM POSITIVE MOXIFLOXACIN (K032399) _bioMerieux, Inc. · LON · Sep 10, 2003 · Microbiology · SESE_ **Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON/K032399 ## Device Facts - **Applicant:** bioMerieux, Inc. - **Product Code:** [LON](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON.md) - **Decision Date:** Sep 10, 2003 - **Decision:** SESE - **Submission Type:** Traditional - **Regulation:** 21 CFR 866.1645 - **Device Class:** Class 2 - **Review Panel:** Microbiology ## Indications for Use VITEK 2® Gram Positive Moxifloxacin is designed for antimicrobial susceptibility testing of Staphylococcus aureus (methicillin-susceptible strains only). It is intended for use with the VITEK 2® System as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents. ## Device Story VITEK® 2 Gram Positive Susceptibility Card performs automated antimicrobial susceptibility testing (AST) for Staphylococcus spp. System uses 64-microwell cards containing premeasured antibiotics and culture medium. Process: pure culture suspension standardized to McFarland 0.5; automated vacuum filling/sealing of cards; incubation at 35.5°C; optical scanning every 15 minutes. Device measures light transmittance to track organism growth. Discriminant analysis algorithm calculates MIC results based on growth characteristics. Results reported as category interpretation (S, I, R) and MIC. Used in clinical laboratories by technicians/microbiologists to guide antibiotic therapy decisions. ## Clinical Evidence Clinical study conducted at three sites using 365 isolates (clinical and challenge sets). Compared VITEK® 2 automated method against NCCLS reference agar dilution. Primary endpoints: Essential Agreement (EA) and Category Agreement (CA). Combined results showed 99.2% EA and 83.3% CA. No major or very major discrepancies observed; 61 minor errors noted, primarily trending toward increased resistance. Performance deemed acceptable per FDA AST guidance. ## Technological Characteristics Automated antimicrobial susceptibility testing system. Uses miniaturized doubling dilution methodology in disposable cards. System performs automated filling, sealing, incubation, and optical monitoring of bacterial growth. Connectivity via VITEK 2 System. Software-based analysis of growth kinetics to determine MIC values. ## Regulatory Identification A fully automated short-term incubation cycle antimicrobial susceptibility system is a device that incorporates concentrations of antimicrobial agents into a system for the purpose of determining in vitro susceptibility of bacterial pathogens isolated from clinical specimens. Test results obtained from short-term (less than 16 hours) incubation are used to determine the antimicrobial agent of choice to treat bacterial diseases. ## Special Controls *Classification.* Class II (special controls). The special control for this device is FDA's guidance document entitled “Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA.” ## Predicate Devices - VITEK® 2 Gram Positive Susceptibility Card with Sparfloxacin (N50510/S141) ## 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} 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY DEVICE ONLY TEMPLATE A. 510(k) Number: k032399 B. Analyte: Moxifloxacin at equivalency concentrations of 0.25 - 8 ug/ml C. Type of Test: Quantitative growth based detection algorithm using optics light detection D. Applicant: bioMerieux, Inc. E. Proprietary and Established Names: VITEK® 2 Gram Positive F. Regulatory Information: 1. Regulation section: 866.1645 Short-Term Antimicrobial Susceptibility Test System 2. Classification: II 3. Product Code: LON System, Test, Automated, Antimicrobial Susceptibility, Short Incubation 4. Panel: 83 Microbiology G. Intended Use: 1. Intended use(s): The VITEK® 2 Antimicrobial Susceptibility Test (AST) is intended to be used with the VITEK® 2 System for the automated quantitative or qualitative susceptibility testing of isolated colonies for most clinically significant aerobic gram-negative bacilli, Staphylococcus spp., Enterococcus spp., Streptococcus agalactiae, and S. pneumoniae. The VITEK® 2 Gram Positive Susceptibility Card is intended for use with the VITEK® 2 System in clinical laboratories as an in vitro test to determine the susceptibility of Staphylococcus spp., Enterococcus spp., and S. agalactiae to antimicrobial agents when used as instructed in the Online Product Information. 2. Indication(s) for use: The indication will include the testing of moxifloxacin at concentrations of 0.25, 0.5, and 2 for a calling range of ≤ 0.25 – ≥ 8 ug/ml on the VITEK® 2 Gram Positive Susceptibility Card. 3. Special condition for use statement(s): For testing Staphylococcus spp. only 4. Special instrument Requirements: Not applicable H. Device Description: {1} Page 2 of 5 Each VITEK® 2 test card contains 64 microwells. A control well, that contains only microbiological culture medium is resident on all cards, with the remaining wells containing premeasured amounts of a specific antibiotic combined with culture medium. A suspension of organism is made in 0.45-0.5% sterile saline from a pure culture and standardized to a McFarland 0.5 standard using the DensiChek. The desired card (s) are placed in the cassette along with an empty tube for the susceptibility card. The cassette is placed into the VITEK® 2 instrument where a susceptibility test will be automatically diluted from the ID suspension by the VITEK® 2. The cards are then automatically vacuum filled; the tubes are cut and the cards sealed prior to proceeding to the Incubator Loading Station. Cards are then transferred from the cassette into the carousel for incubation (35.5° C) and optical scanning during testing. Readings are performed every 15 minutes. I. Substantial Equivalence Information: 1. Predicate device name(s): VITEK® 2 Gram Positive Susceptibility Card with Sparfloxacin 2. Predicate K number(s): N50510/S141 3. Comparison with predicate: | Similarities | | | | --- | --- | --- | | Item | Device | Predicate | | Intended Use | Same | Same | | Test organism | Colonies of Staphylococcus spp. | Colonies of Staphylococcus spp. | | Test Card | VITEK® 2 card format with base broth | same | | Instrument | VITEK® 2 System | VITEK® 2 System | | Differences | | | | Item | Device | Predicate | | Antibiotic | Moxifloxacin at specific concentrations | Sparfloxacin at specific concentrations | | Reading algorithm | Unique for moxifloxacin | Unique for sparfloxacin | J. Standard/Guidance Document Referenced (if applicable): Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA”; NCCLS M7 (M100-S13) “Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard”. K. Test Principle: Optics systems use visible light to directly measure organism growth. These transmittance optics are based on an initial light reading of a well before significant growth has begun. Periodic light transmittance samplings of the same well measure organism growth by how much light is prevented from going through the well. An interpretive call is made between 4 and 16 hours. The VITEK® 2 Susceptibility Card test is based on the microdilution minimum inhibitory concentration technique with concentrations equivalent to standard method concentrations. Several parameters based {2} Page 3 of 5 on the growth characteristics observed are used to provide appropriate input for the MIC calculations. Discriminate analysis is used to develop the algorithm that determines the susceptibility result for all antimicrobials on the VITEK® 2 system. The MIC result must be linked to an organism identification in order to determine a category interpretation. A category interpretation will be reported along with a MIC. L. Performance Characteristics (if/when applicable): 1. Analytical performance: a. Precision/Reproducibility: Twenty-five gram-positive on-scale organisms were tested at three sites with >95% reproducibility. These same organisms were tested at one site three times to determine the within site reproducibility of >95% also. This testing was performed using both the manual dilution of the inoculum and also the automatic dilution method. b. Linearity/assay reportable range: Not applicable c. Traceability (controls, calibrators, or method): | ORGANISM | Reference conc. | Reference | VITEK® Conc. | auto | man | | --- | --- | --- | --- | --- | --- | | | | | | | | | S. aureus ATCC 29213 Range 0.016-0.12 | ≤ 0.6 | 68 | | | | | | 0.12 | 2 | ≤ 0.25 | 70 | 64 | | | 0.25 | | | | | | | 0.5 | | | | | | | | | | | | | E. faecalis ATCC 29212 Range 0.06-0.5 | ≤ 0.6 | 1 | | | | | | 0.12 | 57 | | | | | | 0.25 | 11 | ≤ 0.25 | 70 | 64 | | | 0.5 | 1 | | | | Quality Control was performed during the studies using both the auto-dilution and the manual method of diluting the organisms. Inoculum density control was monitored using the DensiChek instrument. This was standardized weekly with all results recorded and in the expected range. Verification was performed during internal testing. 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: A clinical study was conducted at three sites using the VITEK® 2 card with moxifloxacin and the NCCLS reference agar dilution {3} Page 4 of 5 method prepared as recommended in NCCLS M7 approved standard. Inoculum was prepared with direct colony suspension. Two methods of inoculation (manual and automated) were evaluated. Clinical testing was performed using the automated method of inoculation and the challenge set was tested using both the manual and the automated method. Greater than 99% of the isolates grew in the VITEK® 2 card in less than 16 hours. The following table provides the results form the automated testing. | | total | EA | %EA | Total evaluable | EA of evaluable | %EA | CA | %CA | #R | min | maj | vmj | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Clinical | 306 | 303 | 99 | 110 | 108 | 98.2 | 245 | 80.1 | 42 | 61 | 0 | 0 | | Challenge | 59 | 59 | 100 | 3 | 3 | 100 | 59 | 100 | 2 | 0 | 0 | 0 | | Combined | 365 | 362 | 99.2 | 113 | 111 | 98.2 | 304 | 83.3 | 44 | 61 | 0 | 0 | EA-Essential Agreement CA-Category Agreement R-resistant isolates maj-major discrepancies vmj-very major discrepancies min- minor discrepancies Evaluable results are those that fall within the test range of the reference method and could also be on-scale with the new device if within the plus/minus one well variability. EA is when there is agreement between the reference method and the VITEK® 2 within plus or minus one serial two-fold dilution of antibiotic. CA is when the interpretation of the reference method agrees exactly with the interpretation of the VITEK® 2 result. There are no maj or vmj errors but there are 61 minor errors. There is a definite trend for the VITEK® 2 result to be more resistant so most of the minor errors are one well more resistant but still in EA. Since there is such a high EA and EA of the evaluable the lower CA will be acceptable. An evaluation of the methicillin susceptible S. aureus (MSSA) showed that only 5 of the 43 minor errors observed with the S. aureus group were in the MSSA group with a final CA of 95% for the MSSA group. Manual Dilution: The challenge set of organisms was also tested at one site using the manual method of inoculation with the following performance that demonstrated that there was little or no difference between the two inoculation methods. | | total | EA | % EA | Total evaluable | EA of evaluable | % EA | CA | % CA | #R | min | maj | vmj | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | challenge | 59 | 59 | 100 | 3 | 3 | 100 | 59 | 100 | 2 | 0 | 0 | 0 | b. Matrix comparison: Not applicable {4} Page 5 of 5 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: ≤ 2 (S), 4 (I), ≥ 8 (R) The interpretative criteria and QC are the same as recommended in NCCLS. All values will be included in the package insert. M. Conclusion: The reproducibility, quality control results and overall performance is acceptable as described in the "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA" which was used in the design and evaluation of the study. The appropriate control organisms are included in the labeling and are the same as those recommended in the NCCLS M7-(M100-S13) document. This performance as compared to a standard method demonstrates substantial equivalency to the predicate. --- **Source:** [https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON/K032399](https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON/K032399) **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. 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