The Gamma Phage assay is a lytic phage assay specific for Bacillus anthracis. The Gamma Phage assay (common name) can be used on suspect non-hemolytic, aerobic, gram-positive, "ground-glass"- appearing colonies from sheep blood agar in conjunction with other markers and testing for the identification of Bacillus anthracis. The assay is not intended for screening of blood or plasma donors.

Use of this assay is limited to designated laboratory Response Network (LRN) and Department of Defense (D0D).

Device Description

The gamma phage is a lytic bacteriophage which binds to specific cell-surface components of susceptible bacteria. Their DNA is injected into the bacterium. The gamma phage replicate within the bacterium and produce PlyG lysine (2), resulting in lysis of the infected cell and release of phage. The release of newly synthesized phage leads to another round of phage infection and lysis.

Materials Supplied:

Bacillus anthracis Gamma Phage Suspension, 0.5 ml
. Positive Control, Bacillus anthracis Pasteur Strain Spore Suspension, 1.0 ml
Negative Control, Bacillus cereus Spore Suspension, 1.0 ml ●

Materials required but not supplied:

. 5% Sheep Blood Agar plate
. Inoculating loops, 1ul and 10 ul
Aerosol resistant pipette tips
. Disinfectant

Equipment required:

Pipettor, 5-50 µ1
Incubator, 35+/- 2 °C
Biological Safety Cabinet, Class II
Refrigerator, 2-8 ℃ .

AI/ML Overview

Here's a summary of the acceptance criteria and study information for the Gamma Phage Lysis Assay for the Identification of Bacillus anthracis, based on the provided document:

The document describes a Special 510(k) submission (K143592) for the Gamma Phage Lysis assay, which is specific for Bacillus anthracis. The submission states that the only modification made to the previously cleared predicate device (K051794) is a change in the positive control strain from Bacillus anthracis Pasteur strain to Bacillus anthracis Sterne strain. The document claims this change does not impact assay performance.

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state quantitative acceptance criteria (e.g., specific sensitivity/specificity thresholds) or provide detailed performance metrics (like sensitivity, specificity, accuracy) for the K143592 device itself. Instead, it relies on the substantial equivalence argument, asserting that the performance characteristics are identical to the predicate device because the only change (positive control strain) does not impact assay performance.

Therefore, the "acceptance criteria" can be inferred as maintaining the performance of the predicate device for identifying Bacillus anthracis.

Metric/Characteristic	Acceptance Criteria (Inferred from Predicate)	Reported Device Performance (K143592)
Ability to identify Bacillus anthracis	Equivalent to predicate device K051794	Claimed to be equivalent to predicate device K051794
Specificity for Bacillus anthracis (lytic phage activity)	Equivalent to predicate device K051794	Claimed to be equivalent to predicate device K051794
Consistency of positive and negative controls	Positive control (Sterne strain) yields expected positive result, Negative control (B. cereus) yields expected negative result.	The document implies this would be met through the use of the specified controls.

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

The document does not describe a new clinical or laboratory study with a "test set" to establish the performance of the K143592 device independently. The basis for substantial equivalence is that the only change (positive control strain) does not alter the fundamental performance of the assay. Therefore, there is no specific test set sample size or provenance information for K143592 provided in this document as it pertains to proving the performance of the assay itself. The performance relies on the previous clearance of K051794 and the argument that the modification is minor.

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

Not applicable, as no new independent test set study is described for K143592 to establish ground truth for performance. The performance is considered equivalent to the predicate.

4. Adjudication Method for the Test Set

Not applicable, as no new independent test set study is described.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance

Not applicable. This device is a rapid diagnostic assay for bacterial identification, not an AI-assisted diagnostic tool or an imaging device requiring human reader interpretation in the context of an MRMC study.

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

The device is a laboratory assay. Its performance is inherent to the reagents and protocol. The document does not provide details of an internal "standalone" study for K143592, as its performance is considered unchanged from the predicate device. The assay itself operates "standalone" in the sense that it provides a direct result without human "interpretation" of complex data (like images), but rather observation of lysis.

7. The Type of Ground Truth Used

For the predicate device (K051794) and by extension for K143592, the ground truth for Bacillus anthracis identification would typically be established through:

Culture and biochemical identification: Standard microbiological methods to identify bacterial species.
Molecular methods: Such as PCR, targeting specific B. anthracis genes.
Referral laboratory confirmation: Confirmation by a qualified reference laboratory using a suite of confirmatory tests.

The document implicitly relies on these established methods for identifying Bacillus anthracis to validate the specificity and lytic activity of the gamma phage. The positive and negative controls provided with the kit (e.g., Bacillus anthracis Sterne strain and Bacillus cereus spore suspension) serve as internal ground truth checks for each run of the assay.

8. The Sample Size for the Training Set

Not applicable. This is a traditional diagnostic assay, not a machine learning or AI model that requires a "training set."

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

Not applicable, as there is no training set for this type of device.

Summary

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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

THE SURGEON GENERAL, DEPARTMENT OF THE ARMY KENNETH BERTRAM, MD, PHD PRINCIPAL ASSISTANT FOR ACQUISITION 1430 VETERANS DRIVE FORT DETRICK MD 21702-5009

April 16, 2015

Re: K143592

Trade/Device Name: Gamma Phage Lysis Assay For The Identification Of Bacillus Anthracis Regulatory Class: unclassified Product Code: NVQ Dated: December 17, 2014 Received: December 18, 2014

Dear Dr. Bertram:

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. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. 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); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours.

Uwe Scherf – S for

Sally Hojvat, M. Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health

Enclosure

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Indications for Use

510(k) Number (if known) K143592

Device Name

GAMMA PHAGE LYSIS ASSAY FOR THE IDENTIFICATION OF BACILLUS ANTHRACIS

Indications for Use (Describe)

Use of this assay is limited to designated laboratory Response Network (LRN) and Department of Defense (D0D).

Type of Use (Select one or both, as applicable)

Prescription Use (Part 21 CFR 801 Subpart D)

_ Over-The-Counter Use (21 CFR 801 Subpart C)

PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON A SEPARATE PAGE IF NEEDED.

FOR FDA USE ONLY

Concurrence of Center for Devices and Radiological Health (CDRH) (Signature)

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Gamma Phage Lysis for the Identification of Bacillus anthracis

Submitted by:	Office of Surgeon General, Department of Army
Sponsor's Representative	Kenneth A. Bertram, MD, PhDPrincipal Assistant for AcquisitionU.S. Army Medical Research and Materiel Command (USAMRMC)1430 Veterans DriveFort Detrick, MD 21702-5009
Primary Contact:	Robert E. Miller, PhD, RACDivision of Regulated Activities and Compliance1430 Veterans DriveFort Detrick, MD 21702-5009Telephone: 301-619-0317Fax: 301-619-0197Email: usarmy.detrick.medcom-usammda.mbx.usamrmc-regulatory-affairs@mail.mil
Secondary Contact:	Chandar Thakur, PhD RACDivision of Regulated Activities and Compliance1430 Veterans DriveFort Detrick, MD 21702-5009Telephone: 301-619-0317Fax: 301-619-0197Email: usarmy.detrick.medcom-usammda.mbx.usamrmc-regulatory-affairs@mail.mil
Manufacturer:	Mark Wolcott, PhD MT(ASCP)United States Army Medical Research Institute of Infectious Diseases(USMRIID)Diagnostic Systems Division1425 Porter StreetFt. Detrick, MD 21702Telephone: 301-619-4738
Date Prepared:	04/09/2015

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Trade Name:	Gamma Phage Lysis for the Identification of Bacillus anthracis
Common Name:	Bacillus anthracis Culture, Controls
Classification Name:	Bacteriophage And Controls, B. anthracis Lysis
Submission Type:	Special 510k
Device Class:	Unclassified
Product Code:	NVQ
Predicate Device:	K051794Gamma Phage Lysis for the Identification of Bacillus anthracis

Indications for Use

The Gamma Phage assay is a lytic phage assay specific for Bacillus anthracis. The Gamma Phage assay (common name) can be used on suspect non-hemolytic, aerobic, gram-positive, "ground-glass"appearing colonies from sheep blood agar in conjunction with other markers and testing for the identification of Bacillus anthracis. The assay is not intended for screening of blood or plasma donors.

Use of this assay is limited to designated laboratories within the Laboratory Response Network (LRN) and Department of Defense (D0D).

Device Description and Comparison

Materials Supplied:

Bacillus anthracis Gamma Phage Suspension, 0.5 ml
. Positive Control, Bacillus anthracis Pasteur Strain Spore Suspension, 1.0 ml
Negative Control, Bacillus cereus Spore Suspension, 1.0 ml ●

Materials required but not supplied:

. 5% Sheep Blood Agar plate
. Inoculating loops, 1ul and 10 ul
Aerosol resistant pipette tips
. Disinfectant

Equipment required:

Pipettor, 5-50 µ1

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Incubator, 35+/- 2 °C
Biological Safety Cabinet, Class II
Refrigerator, 2-8 ℃ .

The only modification that was made is a change to the positive control strain (listed above), from the specified Pasteur strain, to the Sterne strain. The change in positive control strain does not impact the performance of the assay and does not substantially alter the 510k Premarket Notification Submission.

Substantial Equivalence:

The modified Gamma Phage Lysis for the Identification of Bacillus anthracis has the same characteristics to those which previously received 510(k) concurrence:

Have the same indication for use
. Use the same operating principle
Incorporate the same materials , and equipment
Has the same specimen collection and preparation instruction ●

The assay differs in that a new positive control strain, from specified Pasteur strain, to the Sterne stain.

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Feature	K051794Predicate Device	K143592Proposed Device
Positive Control	Bacillus anthracis Pasteur strainspore suspension 1.0 ml(BC3132)	Bacillus anthracis Sterne strainviable lyophilized cells (BC3366)Colorado Serum Company(19102) Anthrax Spore Vaccine- 1.0 ml suspension of viableBacillus anthracis Sterne strain34F2 spores
Negative Control	Bacillus cereus sporesuspension 1.0 ml (BC3133)	Bacillus cereus sporesuspension 1.0 ml (BC3133) -sameBacillus cereus lyophilized cells(BC3367)ATCC 14579 - Bacillus cereusfreeze-dried (lyophilized)
Reporting - Capsule StainingTechniques	A positive gamma phage result,in conjunction with a positiveresult for capsule, is consideredconfirmatory identification of B.anthracis. Capsule may bedemonstrated by colonymorphology on bicarbonate agarafter incubation in enhancedCO2 or by staining techniques(India ink, M'Fadyean, orcapsule DFA).	A positive gamma phage result,in conjunction with a positiveresult for capsule, is consideredconfirmatory identification of B.anthracis. Capsule may bedemonstrated by colonymorphology on bicarbonate agarafter incubation in enhancedCO2 or by staining techniques(India ink or M'Fadyean).Difference - Capsule DFAremoved.

Table of Differences Compared to Original Submission (K051794)

Regulation Number and Section

§ 866.3045 In vitro diagnostic device for

Bacillus spp. detection.(a)
Identification. An in vitro diagnostic device forBacillus species (spp.) detection is a prescription device used to detect and differentiate amongBacillus spp. and presumptively identifyB. anthracis and otherBacillus spp. from cultured isolates or clinical specimens as an aid in the diagnosis of anthrax and other diseases caused byBacillus spp. This device may consist ofBacillus spp. antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to presumptively identify bacillus-like organisms in clinical specimens; bacteriophage used for differentiatingB. anthracis from otherBacillus spp. based on susceptibility to lysis by the phage; or antigens used to identify antibodies toB. anthracis (anti-toxin and anti-capsular) in serum. Bacillus infections include anthrax (cutaneous, inhalational, or gastrointestinal) caused byB. anthracis, and gastrointestinal disease and non-gastrointestinal infections caused byB. cereus. (b)
Classification. Class II (special controls). The special controls are set forth in FDA's special controls guideline document entitled “In Vitro Diagnostic Devices forBacillus spp. Detection; Class II Special Controls Guideline for Industry and Food and Drug Administration Staff.” For availability of the guideline document, see § 866.1(e).(c)
Restriction on Distribution. The distribution of these devices is limited to laboratories that follow public health guidelines that address appropriate biosafety conditions, interpretation of test results, and coordination of findings with public health authorities.(d)
Restriction on Use. The use of this device is restricted to prescription use and must comply with the following:(1) The device must be in the possession of:
(i)(A) A person, or his agents or employees, regularly and lawfully engaged in the manufacture, transportation, storage, or wholesale or retail distribution of such device; or
(B) A practitioner, such as a physician, licensed by law to use or order the use of such device; and
(ii) The device must be sold only to or on the prescription or other order of such practitioner for use in the course of his professional practice.
(2) The label of the device shall bear the statement “Caution: Federal law restricts this device to sale by or on the order of a ____”, the blank to be filled with the word “physician” or with the descriptive designation of any other practitioner licensed by the law of the State in which he practices to use or order the use of the device.
(3) Any labeling, as defined in section 201(m) of the Federal Food, Drug, and Cosmetic Act, whether or not it is on or within a package from which the device is to be dispensed, distributed by, or on behalf of the manufacturer, packer, or distributor of the device, that furnishes or purports to furnish information for use of the device contains adequate information for such use, including indications, effects, routes, methods, and frequency and duration of administration and any relevant hazards, contraindications, side effects, and precautions, under which practitioners licensed by law to employ the device can use the device safely and for the purposes for which it is intended, including all purposes for which it is advertised or represented. This information will not be required on so-called reminder-piece labeling which calls attention to the name of the device but does not include indications or other use information.
(4) All labeling, except labels and cartons, bearing information for use of the device also bears the date of the issuance or the date of the latest revision of such labeling.