← Product Code [LON](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON) · K050555 # BD PHOENIX AUTOMATED MICROBIOLOGY SYSTEM - CEFAZOLIN (GP) 2-32 UG/ML (K050555) _Becton, Dickinson & CO · LON · Apr 14, 2005 · Microbiology · SESE_ **Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON/K050555 ## Device Facts - **Applicant:** Becton, Dickinson & CO - **Product Code:** [LON](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON.md) - **Decision Date:** Apr 14, 2005 - **Decision:** SESE - **Submission Type:** Traditional - **Regulation:** 21 CFR 866.1645 - **Device Class:** Class 2 - **Review Panel:** Microbiology ## Intended 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 instrument for identification and antimicrobial susceptibility testing (AST) of bacterial isolates. The system uses sealed, molded polystyrene panels containing 136 micro-wells with various antimicrobial concentrations. Inputs consist of bacterial isolates from pure culture, prepared as an inoculum in Phoenix ID or AST broth. The system utilizes a redox indicator and turbidity measurements to monitor bacterial growth in the presence of antimicrobial agents. The instrument continuously incubates panels at a nominal temperature and takes readings every 20 minutes. Software interprets these readings to provide organism identification, MIC values, and categorical interpretations (S, I, or R). Used in clinical microbiology laboratories by trained technicians to guide antimicrobial therapy decisions. The system provides rapid results compared to traditional manual methods, aiding clinicians in selecting appropriate antibiotic treatments for patients. ## Clinical Evidence Performance evaluated via multi-site clinical study comparing Phoenix System results to NCCLS reference broth microdilution method. Study included clinical, stock, and challenge isolates. For Cefazolin (2-32 µg/mL) with Gram-positive panels, 507 isolates were tested, achieving 100% Essential Agreement and 100% Category Agreement. Intra- and inter-site reproducibility exceeded 95% for Gram-positive isolates. ## Technological Characteristics Automated microdilution system using sealed, molded polystyrene panels (136 micro-wells). Sensing principle: redox indicator and turbidity measurement. Energy source: electrical (instrument). Connectivity: integrated system with proprietary software. Sterilization: not specified. Software: automated interpretation of growth kinetics. ## 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: k050555 B. Purpose for Submission: Addition of the antibiotic cefazolin at concentrations of 2-32 ug/mL to the Gram Positive ID/AST or AST only Phoenix™ panels C. Measurand: Cefazolin at 2-32 ug/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 – Cefazolin Gram Positive 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: 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 of gram-negative aerobic and facultative anaerobic bacteria belonging to the family Enterobacteriaceae and non-Enterobacteriaceae and gram-positive bacteria belonging to the genera Staphylococcus and Enterococcus. {1} Page 2 of 6 The BD Phoenix™ GP Panel: The BD Phoenix™ Automated Microbiology System is intended for the in vitro rapid identification (ID) of gram positive bacteria from pure culture belonging to the genera Staphylococcus, Enterococcus, other gram positive cocci and gram positive bacilli. The BD Phoenix™ Automated Microbiology System is also intended for the quantitative determination of antimicrobial susceptibility by minimal inhibitory concentration (MIC) of most gram-positive bacteria isolates from pure culture belonging to the genera Staphylococcus and Enterococcus. 2. Indication for use: This submission is for the addition of the antibiotic cefazolin at concentrations of 2 – 32 ug/mL to the Gram positive ID/AST or AST only Phoenix™ panels. 3. Special condition for use statement: Prescription Use Only For oxacillin susceptible staphylococci spp. 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 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 broth, which contains an AST indicator, prior to inoculating the panel. The AST broth is a cation-adjusted formulation of Mueller-Hinton broth containing 0.01% Tween 80. After adding the indicator solution to the AST inoculum the color is blue and after inoculation and incubation goes to pink to 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 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 CLSI standards. {2} Page 3 of 6 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: VITEK® System 2. Predicate K number: 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 gram-positive 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 | | 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: Fourteen 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 strains were tested at the concentrations listed (see table below). The Phoenix results demonstrate that the system can produce QC results in the recommended range. | Organism | Concentration | Reference results | PhoenixTM results | | --- | --- | --- | --- | | | | | | | S. aureusATCC 29213Range 0.25-1ug/mL | ≤2 | 252 | 249 | | | 4 | | | | | 8 | | | | | 16 | | | | | 32 | | 1 | | | | | | | S.saprophyticusATCC 3552Range ≤ 4ug/mL | ≤2 | 249 | 246 | | | 4 | 3 | 1 | | | 8 | | | | | 16 | | 1 | | | 32 | | 2 | | | | | | {4} Inoculum density control: The organism suspension density of the ID broth was equivalent to a 0.5 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. 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 was prepared according to the CLSI recommendation and used to compare with the Phoenix™ 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. Twelve hundred and ten isolates were tested but the following table demonstrates the performance of methicillin susceptible staphylococci only since the Phoenix™ generated oxacillin result if resistant will generate a resistant category for cefazolin as recommended by CLSI. The testing of methicillin resistant staphylococci although not included in the evaluation did demonstrate that resistance to cefazolin could be detected but for methicillin resistant isolates the interpretation of cefazolin is based on the oxacillin result. | | EA Tot | EA N | EA % | Eval EA Tot | Eval EA N | Eval EA % | CA N | CA % | #R | min | maj | vmj | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Clinical | 569 | 566 | 99.5 | 3 | 1 | 33.3 | 567 | 99.6 | 0 | 1 | 1 | 0 | | Challenge | 28 | 28 | 100 | 0 | 0 | 0 | 28 | 100 | 0 | 0 | 0 | 0 | | Combined | 597 | 594 | 99.5 | 3 | 1 | 33.3 | 595 | 99.7 | 0 | 1 | 1 | 0 | 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 reference panel result interpretation. The test device had a growth rate of $>95\%$ . # b. Matrix comparison: Not applicable {5} Page 6 of 6 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 = ≤ 8 (S), 16 (I), ≥ 32 (R) for Staphylococcus spp. N. Proposed Labeling: The expected value range, interpretive criteria and QC are the same as recommended by CLSI. 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.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON/K050555](https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/LON/K050555) **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