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.

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 antilitive anaerobic bacteria isolates from pure culture for Enterobacteriaceae and Non-Enterobacteriaceae and most Gram-positive bacteria isolates from pure culture belonging to the genera Staphylococcus , Enterococcus, and Streptococcus.

This premarket notification is for the addition of the antimicrobial agent linezolid at concentrations of 0.25-16 ug/mL to Streptococcus ID/AST or AST only Phoenix panels. Linezolid has been shown to be active in vitro against most strains of microorganisms listed below, as described in the FDA-approved package insert for this antimicrobial agent.

Active In Vitro and in Clinical Infections Against:

Streptococcus agalactiae Streptococcus pneumoniae (penicillin-susceptible strains only) Streptococcus pyogenes

Active In Vitro Against:

Streptococcus pneumoniae (penicillin-resistant strains) Viridans group streptococci

Device Description

The BD Phoenix Automated Microbiology System (Phoenix System) is an automated system for the rapid identification (ID) and antimicrobial susceptibility testing (AST) of clinically relevant bacterial isolates. For testing Streptococcus species the system includes the following components:

. BD Phoenix instrument and software.
. BD Phoenix panels containing biochemicals for organism ID testing and antimicrobial agents or AST determinations.
. BD Phoenix ID Broth used for performing ID tests and preparing AST Broth inoculum.
. BD Phoenix AST-S Broth used for performing AST tests only.
. BD Phoenix AST-S Indicator solution added to the AST Broth to aid in bacterial growth determination.

The Phoenix panel is a sealed and self-inoculating molded polystyrene tray with 136 micro-wells containing dried reagents. Organisms for susceptibility testing must be a pure culture and preliminarily identified as a Gram-negative or Gram-positive isolate. For each isolation equivalent to a 0.5 McFarland standard is prepared in Phoenix ID broth.

The Phoenix AST method is a broth based microdilution test. The Phoenix System utilizes a redox indicator for the detection of organism growth in the presence of an antimicrobial agent. Measurements of changes to the indicator as well as bacterial turbidity are used in the determination of bacterial growth. Each AST panel configuration contains several antimicrobial agents with a wide range of two-fold doubling dilution concentrations.

The instrument houses the panels where they are continuously incubated at a nominal temperature of 35°C. The instrument takes readings of the panels every 20 minutes. The readings are interpreted to give an identification of the isolate, minimum inhibitory concentration (MIC) values and category interpretations, S, I, R or N (susceptible, intermediate, resistant or not susceptible).

AI/ML Overview

Here's a breakdown of the acceptance criteria and study details for the BD Phoenix™ Automated Microbiology System for Linezolid, based on the provided text:

Acceptance Criteria and Device Performance

The acceptance criteria for the BD Phoenix™ Automated Microbiology System when testing Linezolid in streptococcal organisms are based on Essential Agreement (EA) and Category Agreement (CA) with a CLSI reference broth microdilution method.

Acceptance Criteria Type	Acceptance Criteria	Reported Device Performance (Table 1)
Essential Agreement (EA)	Not explicitly stated as a numerical threshold, but implied to be high for "substantially equivalent performance". The results showed 96.0%.	96.0% (n=1071)
Category Agreement (CA)	Not explicitly stated as a numerical threshold, but implied to be high for "substantially equivalent performance". The results showed 98.6%.	98.6% (n=1907)

Note: While specific numerical acceptance criteria for EA and CA are not explicitly given in the provided text, the conclusion of "substantially equivalent performance" implicitly indicates that these reported percentages met the pre-defined acceptance thresholds as per the FDA guidance document.

Study Details

2. Sample Size Used for the Test Set and Data Provenance

Test Set Sample Size: The exact number of individual isolates in the "test set" (clinical, stock, and challenge isolates combined) is not directly stated as a single number. However, the performance metrics provide counts:
- Essential Agreement (EA) was calculated from n = 1071 results.
- Category Agreement (CA) was calculated from n = 1907 results.
Data Provenance: The study used a mix of:
- Clinical isolates: These are typically prospective, collected from patient samples.
- Stock isolates: (Strain collections) could be either retrospective or prospective, depending on how they were obtained.
- Challenge isolates: These are typically curated strains used to challenge the system's performance, often not from recent patient samples.
Country of Origin: "across multiple geographically diverse sites across the United States."

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications

Number of Experts: Not specified.
Qualifications of Experts: Not specified. The ground truth for the test set was established by the CLSI reference broth microdilution method (for clinical isolates) and "expected results" for challenge isolates, rather than individual expert interpretation of the device output. This implies that the 'experts' would be the laboratory personnel performing and interpreting the reference method.

4. Adjudication Method for the Test Set

Adjudication Method: Not applicable in the traditional sense of resolving discrepancies between human readers. The comparative method was between the automated device and a standardized reference laboratory method (CLSI broth microdilution). Discrepancies between the Phoenix System and the reference method were quantified as lack of essential or category agreement, not adjudicated by a third party.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size

MRMC Study: No, an MRMC comparative effectiveness study was not explicitly done in the context of comparing human readers with and without AI assistance. This study focuses on the standalone performance of an automated system against a reference method.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done

Standalone Performance: Yes, the study primarily assessed the standalone performance of the BD Phoenix™ Automated Microbiology System. The device itself automatically interprets the results to give MIC values and categorical interpretations (S, I, R, or N) without direct human intervention in the interpretation process of each reading. Human involvement is in setting up the test and reviewing the final results.

7. The Type of Ground Truth Used

Ground Truth Type:
- Reference Method: For clinical isolates, the ground truth was "results obtained from the CLSI reference broth microdilution method." CLSI (Clinical and Laboratory Standards Institute) methods are widely accepted laboratory standards for antimicrobial susceptibility testing.
- "Expected Results": For challenge isolates, the ground truth was "expected results." These expected results are typically established through robust prior testing using gold-standard methods or expert consensus on known strains.

8. The Sample Size for the Training Set

Training Set Sample Size: Not explicitly mentioned in the provided text. The text describes a "test set" and studies for validation, but does not detail the specific training dataset used to develop the Phoenix System's algorithms.

9. How the Ground Truth for the Training Set Was Established

Training Set Ground Truth Establishment: Not explicitly mentioned or detailed in the provided text. Typically, ground truth for training AST systems would involve a large collection of isolates tested by a recognized reference method (like CLSI broth microdilution) with expert confirmation, similar to how the ground truth for the test set was established.

Summary

{0}------------------------------------------------

510(k) SUMMARY

SUBMITTED BY:	Becton, Dickinson and Company7 Loveton CircleSparks, MD 21152Phone: 410-316-4287Fax: 410-316-4499
CONTACT NAME:	Monica Giguere,Regulatory Affairs Specialist
DATE PREPARED:	May 12, 2005
DEVICE TRADE NAME:	BD Phoenix™ Automated Microbiology System -Linezolid 0.25-16 µg/mL
DEVICE COMMON NAME:	Antimicrobial susceptibility test system-short incubation
DEVICE CLASSIFICATION:	Fully Automated Short-Term Incubation Cycle AntimicrobialSusceptibility Device, 21 CFR 866.1645
PREDICATE DEVICES:	VITEK® System (PMA No. N50510) and BD Phoenix™Automated Microbiology System with Gatifloxacin (K020321,May 23, 2002), Ofloxacin (K020323, April 14, 2002), andLevofloxacin (K020322, March 27, 2002).
INTENDED USE:	The BD Phoenix™ Automated Microbiology System isintended for the rapid identification and in vitro antimicrobialsusceptibility testing of isolates from pure culture of mostaerobic and facultative anaerobic Gram-negative and Gram-positive bacteria of human origin.

DEVICE DESCRIPTION:

. BD Phoenix instrument and software.
. BD Phoenix panels containing biochemicals for organism ID testing and antimicrobial agents or AST determinations.
. BD Phoenix ID Broth used for performing ID tests and preparing AST Broth inoculum.
. BD Phoenix AST-S Broth used for performing AST tests only.
. BD Phoenix AST-S Indicator solution added to the AST Broth to aid in bacterial growth determination.

{1}------------------------------------------------

DEVICE COMPARISON:

The BD Phoenix™ Automated Microbiology System demonstrated substantially equivalent performance when compared with the CLSI reference broth microdilution method. This premarket notification provides data supporting the use of the BD Phoenix™ Automated Microbiology System Streptococcus ID/AST or AST only Phoenix panels with this antimicrobial agent.

SUMMARY OF SUBSTANTIAL EQUIVALENCE TESTING:

The BD Phoenix™ Automated Microbiology System has demonstrated substantially equivalent performance when compared to the CLSI reference broth microdilution method (AST panels prepared according to NCCLS M7). The system has been evaluated as defined in the FDA Draft guidance document, "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA," February 5, 2003.

Site Reproducibility

Intra- and inter-site reproducibility of this antimicrobial agent in the BD Phoenix System was evaluated at three sites using a panel of streptococcal isolates. Each site tested the isolates in triplicate on three different days using one lot of Streptococcus Phoenix panels containing this antimicrobial agent and associated reagents.

The results of the study demonstrate for the this antimicrobial agent there was an overall intra-site reproducibility of greater than 90% and an overall inter-site reproducibility greater than 95% for the streptococcal isolates tested.

{2}------------------------------------------------

Clinical Studies

Clinical, stock and challenge isolates were tested across multiple geographically diverse sites across the United States to demonstrate the performance of the Phoenix antimicrobial susceptibility test with the Streptococcus Phoenix Panel format containing this antimicrobial agent. Phoenix System results for Challenge set isolates were compared to the expected results. Phoenix System results for clinical isolates were compared to the results obtained from the CLSI reference broth microdilution method.

The performance of the Phoenix System was assessed by calculating Essential Agreement (EA) and Category Agreement (CA) to expected/reference results for all isolates tested. Essential Agreement (EA) occurs when the BD Phoenix™ Automated Microbiology System agrees exactly or within + one two-fold dilution to the reference result. Category Agreement (CA) occurs when the BD PhoenixTM Automated Microbiology System agrees with the reference method with respect to the FDA categorical interpretive criteria (susceptible, intermediate, resistant or nonsusceptible).

Table 1 summarizes the performance for the isolates tested in this study.

Table 1: Performance of BD Phoenix System for Streptococcal Organisms by Drug

Antimicrobial	ConcentrationThe first and the mail of a first and the contribution of the county of the many	EA (n)	10/01EA .	CA (n)	Carres and some and an announce i a creat more a more a model or contract and an and an a comments of an and an a comments of an and an a commend of the comments of any and aCAI(%)
ﻭﺍﻟﺘﻌﻠﻴﻘﺎﺕ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓ ﺍﻟﻤﺘﺤﺪﺓlınezolıd	0.25-16 ug/mL	107110/ -	96.0	------------------------------------------------------------------------------------------------------------------------------------------------------------------------------1907ALARING A . A . A . A . A . A . A A	98.6

Conclusions Drawn from Substantial Equivalence Studies

The data collected from the substantial equivalence studies demonstrate that testing on the BD Phoenix™ Automated Microbiology System with this antimicrobial agent is substantially equivalent as outlined in the FDA draft guidance document, "Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA," February 5, 2003. Technological characteristics of this system are substantially equivalent to those used in the VITEK® system, which received approval by the FDA under PMA number N50510 and BD Phoenix™ Automated Microbiology System with Gatifloxacin (K020321, May 23, 2002), Ofloxacin (K020323, April 14, 2002), and Levofloxacin (K020322, March 27, 2002).

{3}------------------------------------------------

DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/3/Picture/1 description: The image shows the seal of the Department of Health & Human Services (HHS) of the United States of America. The seal is circular and features the department's name around the perimeter. In the center of the seal is a stylized emblem, which is a symbol representing health and human services.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

JUL 5 - 2005

Ms. Monica Giguere Regulatory Affairs Specialist BD Diagnostics Systems Becton, Dickinson and Company 7 Loveton Circle Sparks, MD 21152

Re: K051266 Trade/Device Name: BD Phoenix™ Automated Microbiology System Linezolid (0.25-16 µg/mL) - Streptococcus ID/AST or AST Regulation Number: 21 CFR 866.1645 Regulation Name: Fully Automated Short-Term Incubation Cycle Antimicrobial Susceptibility Devices Regulatory Class: Class II Product Code: LON Dated: May 12, 2005 Received: May 16, 2005

Dear Ms. Giguere:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such additional controls. Existing major regulations affecting your device can be found in Title 21, Code of Federal Regulations (CFR), Parts 800 to 895. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); and good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820).

{4}------------------------------------------------

Page 2 -

This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific information about the application of labeling requirements to your device, or questions on the promotion and advertising of your device, please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at (240)276-0484. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html

Sincerely yours,

Sales, a Form

Sally A. Hojvat, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostic Device Evaluation and Safety Center for Devices and Radiological Health

Enclosure

{5}------------------------------------------------

Page 1 of 1

510(k) Number: jQ5124 ملاحا

Device Name: BD Phoenix™ Automated Microbiology System for use with the antimicrobial agent linezolid (0.25-16 ug/mL) - Streptococcus ID/AST or AST only Phoenix Panels.

Indications for Use:

Active In Vitro and in Clinical Infections Against:

Streptococcus agalactiae Streptococcus pneumoniae (penicillin-susceptible strains only) Streptococcus pyogenes

Active In Vitro Against:

Streptococcus pneumoniae (penicillin-resistant strains) Viridans group streptococci

Prescription Use (Per 21 CFR 801.109) Over-the-Counter Use

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of In Vitro Diagnostic Devices (OIVD)

Luddi T. Poole

Division Sign-Off

Office of In Vitro Diagnostic Device Evaluation and Safety

Prescription Use (Per 21 CFR 801.109)

Evaluation and Safety
K051266

Over-the-Counter Use

K051266

BD Diagnostic Systems Becton, Dickinson and Company

Regulation Number and Section

§ 866.1645 Fully automated short-term incubation cycle antimicrobial susceptibility system.

(a)
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.(b)
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.”