Remel Spectra™ MRSA is a selective and differential chromogenic medium recommended for use in the qualitative detection of nasal colonization of methicillin-resistant Staphylococcocus aureus (MRSA) to aid in the prevention and control of MRSA in healthcare settings. The test is performed with anterior nares swab specimens from patients and healthcare workers to screen for MRSA colonization. Spectra™ MRSA is not intended to diagnose MRSA infection or to quide or monitor treatment for infections.

Device Description

Remel Spectra™ MRSA is an opaque medium, which uses a novel chromogen that yields a denim-blue color as a result of phosphatase activity. This enzyme is present in all MRSA. To allow the medium to differentiate MRSA accurately, it contains a combination of antibacterial compounds designed to inhibit the growth of a wide variety of competitor organisms. Also included are compounds that encourage the production of MRSA pathogenicity marker, ensuring expression of the phosphatase enzyme and so providing enhanced sensitivity and specificity.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study details for the Remel Spectra™ MRSA device, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance:

The document doesn't explicitly state pre-defined acceptance criteria in terms of specific percentages for sensitivity, specificity, or agreement. Instead, it presents the device's performance metrics as a comparison against established reference methods (traditional culture, Oxacillin MIC, and PBP2' testing). The implicit acceptance is that the device demonstrates comparable and high performance to these methods.

Metric (vs. Traditional Culture)	Acceptance Criteria (Implied)	Reported Device Performance (Spectra™ MRSA at 24 hours vs. Traditional Culture at 48 hours)
% Agreement MRSA	High agreement	95.2% (95% CI = 89.2–98.4%)
% Agreement Non-MRSA	High agreement	99.1% (95% CI = 98.0-99.7%)
Overall Agreement	High agreement	98.6% (95% Cl = 97.5-99.3%)

Metric (vs. Oxacillin MIC)	Acceptance Criteria (Implied)	Reported Device Performance (Spectra™ MRSA at 24 hours vs. Oxacillin MIC)
Sensitivity	High sensitivity	95.4% (95% CI = 89.6-98.5%)
Specificity	High specificity	99.7% (95% CI = 98.9-100%)
Overall Agreement	High agreement	99.1% (95% CI = 98.1-99.6%)
Positive Predictive Value (PPV)	High PPV	98.1% (95% Cl = 93.4-99.8%)
Negative Predictive Value (NPV)	High NPV	99.2% (95% Cl = 98.2–99.8%)

Metric (vs. PBP2')	Acceptance Criteria (Implied)	Reported Device Performance (Spectra™ MRSA at 24 hours vs. PBP2')
Sensitivity	High sensitivity	95.4% (95% CI = 89.6-98.5%)
Specificity	High specificity	99.7% (95% CI = 98.9-100%)
Overall Agreement	High agreement	99.1% (95% CI = 98.1-99.6%)
Positive Predictive Value (PPV)	High PPV	98.1% (95% Cl = 93.4-99.8%)
Negative Predictive Value (NPV)	High NPV	99.2% (95% Cl = 98.2–99.8%)

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

Sample Size: 767 prospective anterior nare surveillance specimens.
Data Provenance: The specimens were collected from "four geographically diverse regions of the United States." The study was "prospective."

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

The document does not specify the number or qualifications of experts directly. The ground truth was established through a combination of traditional laboratory methods:

Identification of S. aureus: Latex agglutination test or a biochemical identification system. These are standard laboratory procedures usually performed by trained laboratory technologists/scientists.
Susceptibility Testing (for MRSA confirmation): Antibiotic gradient method for oxacillin and the Oxoid PBP2' test for detection of penicillin-binding protein 2a. Again, these are standard laboratory tests typically interpreted by trained personnel.

4. Adjudication Method for the Test Set:

The document does not describe an explicit "adjudication method" in the sense of multiple human readers independently assessing the Spectra™ MRSA results and then resolving discrepancies. Instead, the Spectra™ MRSA results were directly compared to the established ground truth obtained from standard laboratory methods (traditional culture, identification, and susceptibility testing).

5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study Was Done:

No, an MRMC comparative effectiveness study involving human readers with and without AI assistance was not done. This device is a culture medium, not an AI diagnostic tool that assists human readers.

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

Yes, the primary clinical accuracy study evaluated the standalone performance of the Spectra™ MRSA chromogenic medium. Its direct output (denim-blue colonies indicating MRSA) was compared against the gold standard laboratory methods. There is no "human-in-the-loop" component for this specific device beyond standard laboratory interpretation of culture plates or biochemical/susceptibility tests.

7. The Type of Ground Truth Used:

The ground truth was established through a combination of traditional microbiology laboratory methods, including:

Traditional Culture: Tryptic Soy Agar with 5% Sheep Blood Agar (TSA with 5% SBA).
Biochemical Identification: Latex agglutination test or a biochemical identification system for S. aureus.
Susceptibility Testing/Pathogen Marker Detection: Antibiotic gradient method for oxacillin and the Oxoid PBP2' test for detection of penicillin-binding protein 2a.
The combination of these methods serves as the expert consensus-based laboratory standard for identifying and confirming MRSA colonization.

8. The Sample Size for the Training Set:

The document does not explicitly mention a separate "training set" or "training data" for this device. As a chromogenic culture medium, its performance is based on its inherent biochemical and microbiological properties, not on a machine learning model that requires training data. The "Summary of Performance Data" describes a clinical validation study (test set).

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

Since there is no mention of a separate training set for a machine learning model, this question is not applicable to the development of this specific device. The device's formulation inherently relies on known biochemical reactions and selective agents, rather than being "trained" on data.

Summary

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K073027

510(k) CLINICAL TRIAL SUMMARY

11 28

Spectra™ MRSA Device Trade Name:

Remel Spectra™ MRSA is a selective and differential chromogenic Intended Use: medium recommended for use in the qualitative detection of nasal colonization of methicillin-resistant Staphylococcocus aureus (MRSA) to aid in the prevention and control of MRSA in healthcare settings. The test is performed with anterior nares swab specimens from patients and healthcare workers to screen for MRSA colonization. Spectra™ MRSA is not intended to diagnose MRSA infection or to quide or monitor treatment for infections.

Remel Spectra™ MRSA is an opaque medium, which uses a novel Device Description: chromogen that yields a denim-blue color as a result of phosphatase activity. This enzyme is present in all MRSA. To allow the medium to differentiate MRSA accurately, it contains a combination of antibacterial compounds designed to inhibit the growth of a wide variety of competitor organisms. Also included are compounds that encourage the production of MRSA pathogenicity marker, ensuring expression of the phosphatase enzyme and so providing enhanced sensitivity and specificity.

Summary of Performance Data:

Clinical Accuracy:

The performance of Spectra™ MRSA was evaluated at four geographically diverse regions of the United States. A total of seven hundred sixty-seven (767) prospective anterior nare surveillance specimens were tested. Results from the Spectra™ MRSA at 24 hours incubation were compared to results obtained from traditional culture on Tryptic Sov Agar with 5% Sheep Blood Agar) after 48 hours incubation. During the course of this study, one swab was used to inoculate both plates, with the Blood Agar plate being inoculated first for all specimens. The overall recovery of MRSA on Spectra™ MRSA at 24 hours was 95.4% (104/109) compared to recovery of 96.3% (105/109) on Blood Agar at 48 hours.

Suspect isolates of S. aureus were identified using a latex agglutination test or a biochemical identification system. Susceptibility testing was performed using an antibiotic gradient method for oxacillin and the Oxoid PBP2' test for the detection of the penicillin-binding protein 2a. The overall agreement for detection of MRSA and non-MRSA by denim blue colonies isolated on Spectra™ MRSA at 24 hours compared to identification and susceptibility testing as described was 99.1% (760/767). The positive and negative predictive values for Spectra™ MRSA compared to the Oxoid PBP2' test were 98.1% and 99.2% respectively.

	Traditional Culture
	+	-
Spectra™MRSA	+	100	6*
	-	5	656
TOTAL		105	662

% Agreement MRSA: 95.2% (95% CI = 89.2–98.4%) Non-MRSA: 99.1% (95% CI = 98.0-99.7%) Overall: 98.6% (95% Cl = 97.5-99.3%)

*Four MRSA positive specimens were negative by traditional culture at 48 hours. Note : CI = Confidence Interval

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		Oxacillin MIC
		+	-
Spectra™MRSA	+	104	2
	-	5	656
TOTAL		109	658

		PBP2'
		+	-
SpectraTM	+	104	2
MRSA	-	5	656
TOTAL		109	658

% Aareement MRSA: 95.4% (95% Cl = 89.6-98.5%) Non-MRSA: 99.7% (95% CI = 98.9-100%) Overall: 99.1% (95% CI = 98.1-99.6%)

Sensitivity: 95.4% (95% CI = 89.6-98.5%) Specificity: 99.7% (95% CI = 98.9-100%) Agreement: 99.1% (95% CI = 98.1-99.6%) Positive Predictive Value: 98.1% (95% Cl = 93.4-99.8%) Negative Predictive Value: 99.2% (95% Cl = 98.2–99.8%)

Overall Agreement:

	MRSA	Non-MRSA
Spectra™ MRSA vs. traditional culture	95.2%(100/105)(95% CI = 89.6–98.5%)	99.1%(656/662)(95% CI = 98.9–100%)
Spectra™ MRSA vs. PBP2'	95.4%(104/109)(95% CI = 89.6-98.5%)	99.7%(656/658)(95% CI = 98.9-100%)
Spectra™ MRSA vs. Oxacillin MIC	95.4%(104/109)(95% CI = 89.6-98.5%)	99.7%(656/658)(95% CI = 98.9-100%)

*Four MRSA positive specimens were negative by traditional culture at 48 hours.

Performance Compared to Commercially Available Devices:

Spectra™ MRSA was compared to traditional culture and susceptibility testing and the BD BBL™ CHROMagar™ MRSA with a total of 273 prospective nasal surveillance specimens. One swab was used to inoculate Blood Agar first and Spectra™ MRSA second. The second swab was used to inoculate the BD BBL™ CHROMagar™ MRSA. There was 98.9% agreement with traditional culture and susceptibility testing, and 97,1% agreement with the BD BBL™ CHROMagar™ MRSA. In this study, two nasal swabs were collected per patient.

Interfering Substances:

Commonly used medicinal substances and transport media, as well as human blood and mucous were evaluated for potential interference of the chromogenic reaction of Spectra™ MRSA. No interference was observed.

Reproducibility:

Reproducibility testing was conducted at four sites on three separate days with twenty blinded strains of Staphylococcus aureus. The strains consisted of 12 MRSA, 1 BORSA. MRSA and MSSA strains produced the expected result with Spectra™ MRSA 100% of the time at 24 hours. BORSA demonstrated variable results.

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Image /page/2/Picture/1 description: The image shows the logo for the Department of Health & Human Services USA. The logo consists of a circle with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES USA" around the perimeter. Inside the circle is an image of an eagle.

Public Health Service

FEB 28 2008

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

Mary Ann Silvius Director Clinical Marketing Remel Products Thermo Fisher Scientific 12076 Santa Fe Drive Lenexa, KS 66215

K073027 Trade/Device Name: Remel Spectra™ MRSA Regulation Number: 21 CFR 866.1700 Regulation Name: Culture media, Antimicrobial susceptibility test, excluding Mueller Hinton Agar Regulatory Class: Class II Product Code: JSO Dated: January 28, 2008 Received: January 30, 2008

Dear Ms. Silvius:

Re:

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).

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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,

Sally a. Hogg

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

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INDICATIONS FOR USE

510(k) Number (if known): K073027

Device Name: Spectra™ MRSA

Indications For Use: Remel Spectra™ MRSA is a selective and differential chromogenic medium recommended for use in the qualitative detection of nasal colonization of methicillin-resistant Staphylococcocus aureus (MRSA) to aid in the prevention and control of MRSA in healthcare settings. The test is performed with anterior nares swab specimens from patients and healthcare workers to screen for MRSA colonization. Spectra™ MRSA is not intended to diagnose MRSA infection or to guide or monitor treatment for infections.

Prescription Use_ (Part 21 CFR 801 Subpart D)

AND/OR

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

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

Concurrence of CDRH, Office of Device Evaluation (ODE)

Freddie h. Poole
Division Sign-Off

Office of In Vitro Diagnostic Device Evaluation and Safety

510(k) K073027

Regulation Number and Section

§ 866.1700 Culture medium for antimicrobial susceptibility tests.

(a)
Identification. A culture medium for antimicrobial susceptibility tests is a device intended for medical purposes that consists of any medium capable of supporting the growth of many of the bacterial pathogens that are subject to antimicrobial susceptibility tests. The medium should be free of components known to be antagonistic to the common agents for which susceptibility tests are performed in the treatment of disease.(b)
Classification. Class II (performance standards).