← Product Code [LON](/productcode/LON) · K050982 # BD PHONIX AUTOMATED MICROBIOLOGY SYSTEM - CEFOTAXIME STREP (0.0625-4UG/ML) (K050982) _Becton, Dickinson & CO · LON · May 24, 2005 · Microbiology · SESE_ **Canonical URL:** https://fda-staging.innolitics.com/device/K050982 ## Device Facts - **Applicant:** Becton, Dickinson & CO - **Product Code:** [LON](/productcode/LON.md) - **Decision Date:** May 24, 2005 - **Decision:** SESE - **Submission Type:** Traditional - **Regulation:** 21 CFR 866.1645 - **Device Class:** Class 2 - **Review Panel:** Microbiology ## Indications for Use The BD Phoenix™ Automated Microbiology System is intended for the rapid identification and in vitro antimicrobial susceptibility testing of isolates from pure culture of most aerobic and facultative anaerobic Gram-negative and Gram-positive bacteria of human origin. ## Device Story The BD Phoenix System is an automated microbiology platform for rapid identification and antimicrobial susceptibility testing (AST) of bacterial isolates. The system utilizes molded polystyrene panels containing 136 micro-wells with dried biochemicals and antimicrobial agents. Input consists of a pure culture bacterial isolate prepared in broth to a 0.5 McFarland standard. The system performs broth microdilution testing, using a redox indicator and turbidity measurements to detect bacterial growth in the presence of antimicrobial agents. Panels are incubated at 35°C within the instrument, with automated readings taken every 20 minutes. The system software interprets these readings to provide MIC values and categorical interpretations (S, I, R, or N). Used in clinical microbiology laboratories by trained personnel, the output assists clinicians in selecting appropriate antibiotic therapy for patients with bacterial infections. ## Clinical Evidence Performance was evaluated using clinical, stock, and challenge isolates of streptococcal species. The system was compared to the CLSI reference broth microdilution method. Results demonstrated an overall intra-site reproducibility of ≥97.9% and inter-site reproducibility of 99.3%. Essential Agreement and Category Agreement metrics were used to validate performance against reference results. ## Technological Characteristics Automated growth-based system using colorimetric oxidation-reduction redox indicator. Materials: molded polystyrene trays with 136 micro-wells. Energy: 35°C incubation. Connectivity: Automated instrument with barcode scanning. Software: Rule-based 'EXPERT' system using CLSI guidelines. Inoculum: 0.5 McFarland standard. ## 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® System (PMA No. N50510) - BD Phoenix™ Automated Microbiology System with Gatifloxacin ([K020321](/device/K020321.md)) - BD Phoenix™ Automated Microbiology System with Ofloxacin ([K020323](/device/K020323.md)) - BD Phoenix™ Automated Microbiology System with Levofloxacin ([K020322](/device/K020322.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 6 # 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY TEMPLATE A. 510(k) Number: K050982 B. Purpose for Submission: Addition of the antibiotic cefotaxime to the Phoenix™ SMIC/ID and SMIC Panels C. Measurand: Cefotaxime 0.0625 – 4 µg/mL D. Type of Test: Antimicrobial Susceptibility Test (Quantitative and Qualitative) colorimetric oxidation-reduction, growth-based E. Applicant: Becton, Dickinson & Company F. Proprietary and Established Names: BD Phoenix™ Automated Microbiology System – Cefotaxime (strep) 0.0625 – 4 µg/mL G. Regulatory Information: 1. Regulation section: 21 CFR 866.1645 Fully Automated Short-Term Incubation Cycle Antimicrobial 2. Classification: Class II 3. Product Code: LON 4. Panel: 83 Microbiology H. Intended Use: 1. Intended use(s): BD Phoenix™ Automated Microbiology System: The BD Phoenix™ Automated Microbiology System is intended for in vitro quantitative determination of antimicrobial susceptibility by minimal inhibitory concentration (MIC) of most gram-negative aerobic and facultative anaerobic bacteria belonging to the family Enterobacteriaceae and non-Enterobacteriaceae and gram-positive bacteria belonging to the genera Staphylococcus, Enterococcus and Streptococcus. {1} Page 2 of 6 The BD Phoenix™ SMIC/ID and SMIC Panel is intended for the *in vitro* rapid identification (ID) of bacteria from pure culture belonging to the genera *Streptococcus*. The BD Phoenix™ SMIC/ID and SMIC panels are also intended for the quantitative determination of antimicrobial susceptibility by minimal inhibitory concentration (MIC) of most bacteria isolates from pure culture belonging to the genera *Streptococcus* when used with the BD Phoenix™ Automated Microbiology System. 2. Indication(s) for use: This submission is for the addition of the antibiotic cefotaxime at concentrations of 0.0625 – 4 µg/mL to the Streptococcus ID/AST or AST only Phoenix™ panels. 3. Special condition for use statement(s): Prescription Use Only 4. Special instrument Requirements: Not Applicable I. Device Description: The BD Phoenix™ Automated Microbiology System includes instrumentation and software, sealed and self-inoculating molded polystyrene trays with 136 micro-wells containing dried reagents, and specific inoculum broth formulations for ID and AST-S Indicator. The organism to be tested must be a pure culture and be preliminarily identified as gram positive or gram negative. Colonies are then suspended in broth, and equated to a 0.5 McFarland with the recommendation to use the BD CrystalSpec™ Nephelometer. A further dilution is made into an AST-S broth, which contains an AST-S indicator, prior to inoculating the panel. The AST-S broth is a non-blood, cation-adjusted broth containing pancreatic digest of casein, peptic digest of animal tissue, sodium chloride, 0.010% of Tween 80 and other additional supplements for optimization of streptococcal growth. After adding the indicator solution to the AST-S inoculum, the color is blue, and after inoculation and incubation, it changes to pink then colorless as reduction in the panel well proceeds. Inoculated panels are barcode scanned and loaded into the BD Phoenix™ Automated Microbiology System instrument where the panels are continuously incubated at 35°C. The resulting AST has a final inoculum of 5 × 10⁵ CFU/ml. The instrument incubates, reads and records the results of the biochemical substrates and antimicrobial agents and interprets the reactions to give an ID of the isolate and MIC value and category interpretation of the antimicrobial agents. Organisms growing in the presence of a given antimicrobic agent reduce the indicator, signaling organism growth and resistance to the antimicrobic agent. Organisms killed or inhibited by a given antimicrobic do not cause reduction of the indicator and therefore do not produce a color change. Additional interpretation is done using software driven "EXPERT" System using rules derived from the Clinical and Laboratory Standards Institute (CLSI). {2} Readings are taken every 20 minutes with an ID result available between 2-12 hours and an AST result available between 4-16 hours. This is only an autoread result; there are no manual readings possible. ## J. Substantial Equivalence Information: 1. Predicate device name(s): VITEK® System 2. Predicate K number(s): N50510 3. Comparison with predicate: | Similarities | | | | --- | --- | --- | | Item | Device | Predicate | | Intended use | Intended for the in vitro rapid identification (ID) and quantitative determination of antimicrobial susceptibility by minimal inhibitory concentration (MIC) of most bacteria. | same | | Isolates | Isolated colonies from culture used | Isolated colonies from culture used | | Results | Report results as minimum inhibitory concentration (MIC) and categorical interpretation (SIR) | Report results as minimum inhibitory concentration (MIC) and categorical interpretation (SIR) | | Incubation conditions | <16 hours | <16 hours | | Type of Test | Automated | Automated | | Differences | | | | Item | Device | Predicate | | Inoculum preparation | Inoculum density equated to 0.5 McFarland standard | Inoculum density equated to 1.0 McFarland standard | | Reading algorithm | Results are determined from serial twofold dilutions of antimicrobial agents | Results are determined from extrapolation of doubling dilutions | | Technology | Automated growth based enhanced by use of a redox indicator (colorimetric oxidation-reduction) to detect organism growth. | Automated growth based with detection using an attenuation of light measured by an optical scanner. | ## 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-S15) "Methods {3} for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard." # L. Test Principle: The system employs conventional, colorimetric, fluorogenic and chromogenic substrates to identify the genus and species of the isolate. The AST portion of the BD Phoenix™ Automated Microbiology System is a broth based microdilution method that utilizes a redox indicator (colorimetric oxidation-reduction) to enhance detection of organism growth. The MIC is determined by comparing growth in wells containing serial two-fold dilutions of an antibiotic to the growth in "growth control wells" which contain no antibiotic. # M. Performance Characteristics (if/when applicable): # 1. Analytical performance: # a. Precision/Reproducibility: Twenty-one isolates were evaluated for site to site and inter site reproducibility demonstrating $>95\%$ reproducibility. The ten isolate study described in the guidance document was used (10 organisms tested 3 times on 3 days at 3 sites). # b. Linearity/assay reportable range: Not applicable # c. Traceability, Stability, Expected values (controls, calibrators, or method) CLSI recommended Quality Control strain was tested at the concentrations listed (see table below). The Phoenix™ results demonstrate that the system can produce QC results in the recommended range. The mode for the reference method and the test device are the same. Quality Control Table | ORGANISM | Conc. | Reference results | PhoenixTM results | | --- | --- | --- | --- | | | | | | | S. pneumoniaeATCC 49619Expected Range:0.03 - 0.12 μg/mL | <=0.0625 | 80 | 74 | | | 0.125 | 43 | 49 | | | 0.25 | | | | | 0.5 | | | | | 1 | | | | | 2 | | | | | 4 | | | | | >4 | | | {4} Inoculum density control: The organism suspension density of the ID broth was equivalent to a $0.5\mathrm{McFarland}$ standard using the $\mathrm{BBL}^{\mathrm{TM}}$ CrystalSpec™ Nephelometer which was verified each day of testing. Internal data was used to demonstrate that the use of the $\mathrm{BBL}^{\mathrm{TM}}$ CrystalSpec™ Nephelometer would produce reproducible results. Five different instruments were used. Additional testing on 5 streptococcal strains was performed to demonstrate acceptable performance for streptococcal species. # 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: The CLSI recommended broth dilution reference panel with $2 - 5\%$ lysed horse blood was prepared according to the CLSI recommendation and used to compare with the PhoenixTM results. Clinical testing was performed at four sites. The testing included both fresh clinical isolates and stock isolates along with a challenge set with known results. An additional collection of clinical isolates was tested to provide more resistant and on scale results. A comparison of all results was provided to the reference method with the following agreement. Clinical + Challenge | | EA Tot | EA N | EA % | Eval EA Tot | Eval EA N | Eval EA % | CA N | CA % | #R | min | maj | vmj | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Clinical | 1804 | 1763 | 97.7 | 408 | 376 | 92.2 | 1763 | 97.7 | 42 | 38 | 1 | 2 | | Challenge 1 | 205 | 202 | 98.5 | 70 | 69 | 98.6 | 193 | 94.0 | 86 | 12 | 0 | 0 | | Combined | 2009 | 1965 | 97.8 | 478 | 445 | 93.1 | 1956 | 97.4 | 128 | 50 | 1 | 2 | # 1 Challenge and Supplemental isolates EA-Essential Agreement CA-Category Agreement R-resistant isolates maj-major discrepancies vmj-very major discrepancies min-minor discrepancies Essential agreement (EA) is when the BD Phoenix™ panels agree with the reference test panel results exactly or within one doubling dilution of the reference method. Category agreement (CA) is when the BD Phoenix™ panel result interpretation agrees exactly with the {5} reference panel result interpretation. Evaluable (Eval) are results that are within the test range and on scale. The test device had a growth rate of $>95\%$ . # b. Matrix comparison: Not applicable # 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 | Cefotaxime | S | I | R | | --- | --- | --- | --- | | Streptococcus pneumoniae (non-meningitis) | ≤ 1 | 2 | ≥ 4 | | Streptococcus pneumoniae (meningitis) | ≤ 0.5 | 1 | ≥ 2 | | Streptococcus spp. Other than Streptococcus pneumoniae | | | | | Beta hemolytic group* | ≤ 0.5 | --- | --- | | Viridans group | ≤ 1 | 2 | ≥ 4 | * "The absence of resistant strains precludes defining any results categories other than 'susceptible'. For strains yielding results suggestive of a 'nonsusceptible' category, organism identification and antimicrobial susceptibility test results should be confirmed." # N. Proposed Labeling: The QC expected value range and interpretive criteria as recommended by CLSI for Streptococcus spp. are listed. All values will be included in the package insert. # O. Conclusion: The submitted information in this premarket notification is complete and supports a substantial equivalence decision. --- **Source:** [https://fda-staging.innolitics.com/device/K050982](https://fda-staging.innolitics.com/device/K050982) **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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