MRSASelect is a selective and differential chromogenic medium for the qualitative detection of nasal colonization of methicillin-resistant Staphylococcus aureus (MRSA) to aid in the prevention and control of MRSA infections in healthcare settings. The test can be performed on anterior nares specimens from patients and healthcare workers to screen for MRSA colonization. MRSASelect is not intended to diagnose MRSA infection nor to guide or monitor treatment of infection. Results can be interpreted after 18 - 28 hours incubation.

Device Description

The Bio-Rad MRSASelect is a selective and differential chromogenic culture medium for the qualitative detection of MRSA from anterior nares specimens. Results can be interpreted after 18 - 28 hours incubation.

AI/ML Overview

Here's an analysis of the acceptance criteria and study proving the device meets them, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly state pre-defined acceptance criteria for the performance metrics (sensitivity, specificity, PPV, NPV). However, it reports the device's performance, and since the 510(k) was cleared, it can be inferred that these reported values were deemed acceptable by the regulatory body.

Performance Metric	Acceptance Criteria (Inferred)	Reported Device Performance (18-28 hours incubation)
Sensitivity (Sen)	Deemed acceptable by FDA	100%
Specificity (Spec)	Deemed acceptable by FDA	98%
PPV	Deemed acceptable by FDA	86%
NPV	Deemed acceptable by FDA	100%

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

Sample Size: A total of 200 surveillance samples.
Data Provenance: The study was conducted at "two geographically diverse hospitals" with "fresh anterior nares surveillance specimens." This indicates the data is prospective and originated from clinical settings, likely within the country where the Bio-Rad MRSASelect is seeking approval (France is the sponsor, but the 510(k) is for the US market, so the hospitals would likely be in the US or a similar regulatory region). The document doesn't explicitly state the country of origin but implies clinical relevance for the 510(k) submission.

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

The document does not explicitly mention the number of experts or their qualifications for establishing the ground truth. It describes the ground truth process as "Routine culture was defined as isolation of Staphylococci on Trypticase Soy Agar with 5% blood, with identification confirmed by coagulase and Oxacillin susceptibility using E-Test." This implies standard laboratory procedures were followed, which are typically performed by trained medical laboratory scientists or microbiologists.

4. Adjudication Method for the Test Set

The document does not describe any specific adjudication method (like 2+1 or 3+1). The ground truth was established through a defined "routine culture" process, which is a laboratory standard rather than a subjective expert assessment requiring adjudication.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study evaluates a diagnostic aid where human readers interpret results, and the document describes a standalone diagnostic test (culture medium) where the output is directly observed (colony growth and color) rather than interpreted subjectively by multiple readers. The device performs the detection, not aids human interpretation of complex images.

6. Standalone Performance

Yes, a standalone performance study was done. The entire performance evaluation focuses on the Bio-Rad MRSASelect culture medium's ability to detect MRSA directly from samples, independent of human interpretation other than observing the results of the culture. The results (sensitivity, specificity, PPV, NPV) are reported for the device itself against the routine culture gold standard.

7. Type of Ground Truth Used

The ground truth used was routine culture and laboratory confirmation. Specifically:

Isolation of Staphylococci on Trypticase Soy Agar with 5% blood.
Identification confirmed by coagulase test.
Oxacillin susceptibility confirmed using E-Test.

This is a robust and long-established method for confirming bacterial identification and antibiotic resistance.

8. Sample Size for the Training Set

The document does not mention a separate training set. The performance data provided is for the evaluation of the finished product, not for the development or training of the chromogenic medium formulation itself. Culture media are typically developed through iterative formulation and testing, but the 510(k) submission focuses on the final product's clinical performance.

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

Since no separate training set is mentioned in the provided text, the method for establishing its ground truth is also not described.

Summary

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Bio-Rad MRSASelect Culture Media 510(k) Submission

Page 19 of 73

K081212

JUN 1 3 2008

510(k) SUMMARY

Date of Summary	April 28, 2008
Product Name	Bio-Rad MRSASelectA selective medium for the detection and directidentification of methicillin-resistant Staphylococcusaureus. Results can be interpreted after 18 - 28 hoursincubation.
Sponsor	Bio-Rad3 Boulevard Raymond Poincaré92430 Marnes-la-CoquetteFrance
Correspondent	MDC Associates, LLCFran White, Regulatory Consultant163 Cabot StreetBeverly, MA 01915

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Substantially Equivalent Device

MRSASelect with extended incubation times is substantially equivalent to MRSASelect (reference 510(k) K070361).

Manufacturer: Bio-Rad Product: MRSASelect

Product Attribute	Bio-Rad MRSASelect™(18 - 28 hours incubation)	Bio-Rad MRSASelect™(24 hours incubation)	SubstantiallyEquivalent?
Intended use	MRSASelect is a selectiveand differentialchromogenic medium forthe qualitative detection ofnasal colonization ofmethicillin-resistantStaphylococcus aureus(MRSA) to aid in theprevention and control ofMRSA infections inhealthcare settings. Thetest can be performed onanterior nares specimensfrom patients andhealthcare workers toscreen for MRSAcolonization. MRSASelectis not intended to diagnoseMRSA infection nor toguide or monitor treatmentof infection. Results canbe interpreted after 18 - 28hours incubation.	MRSASelect is a selectiveand differentialchromogenic medium forthe qualitative detection ofnasal colonization ofmethicillin-resistantStaphylococcus aureus(MRSA) to aid in theprevention and control ofMRSA infections inhealthcare settings. Thetest can be performed onanterior nares specimensfrom patients andhealthcare workers toscreen for MRSAcolonization. MRSASelectis not intended to diagnoseMRSA infection nor toguide or monitor treatmentof infection.	√
Sample	Nasal swabs	Nasal swabs	√
Testmethodology	Chromogenic Media	Chromogenic Media	√

PRODUCT DESCRIPTION:

Methicillin-resistant Staphylococcus aureus is a major cause of nosocomial and life threatening infections which have been associated with significantly higher rates of mortality and morbidity.

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Bio-Rad MRSASelect Culture Media 510(k) Submission

INTENDED USE:

SUMMARY OF TECHNOLOGY:

MRSASelect is a selective medium for the detection and direct identification of MRSA. The selectivity of this medium is based on the presence of an antibiotic/antifungal mixture and an optimized salt concentration and that inhibits the growth of yeast and the majority of Gram negative and Gram positive bacteria with the exception of methicillin-resistant staphylococci. Identification is based on the cleavage of a chromogenic substrate by a specific enzymatic activity of Staphylococcus aureus leading to a strong pink coloration of the Staphylococcus aureus colonies.

Within 18 - 28 hours incubation time methicillin-resistant Staphylococcus aureus produce small pink colonies on MRSASelect. Coagulase negative methicillin-resistant staphylococci that do not metabolize the chromogenic substrate appear as colorless or white colonies (possibly light pink). Methicillin sensitive staphylococci (MSS) are inhibited.

PERFORMANCE DATA:

Performance of MRSASelect Extended Incubation was evaluated at two geographically diverse hospitals with fresh anterior nares surveillance specimens. A total of 200 surveillance samples were evaluated. MRSA on routine culture was defined as isolation of Staphylococci on Trypticase Soy Agar with 5% blood, with identification confirmed by coagulase and Oxacillin susceptibility using E-Test. MRSASelect plates were incubated at 35 - 37ºC at ambient conditions. Plates were read after 18, 20, 24, 28 hours incubation. No difference in performance was noted at the defined incubation times.

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Summary Performance Data

A total of 200 samples were tested at two sites against routine culture (blood agar plate, coagulase and susceptibility), and MRSASelect. MRSASelect plates were read and results read at 18, 20, 24 and 28 hours incubation.

Comparison with Routine Culture

	Routine Culture
		pos	neg	total
					sen	100%
	Pos	18	3	21	spec	98%
MRSA Select18 hours	Neg	0	179	179	ppv	86%
		18	182	200	npv	100%

	Routine Culture
		pos	neg	total
					sen	100%
	Pos	18	3	21	spec	98%
MRSA Select20 hours	Neg	0	179	179	ppv	86%
		18	182	200	npv	100%

	Routine Culture
		pos	neg	total
					sen	100%
	Pos	18	3	21	spec	98%
MRSA Select24 hours	Neg	0	179	179	ppv	86%
		18	182	200	npv	100%

	Routine Culture
		pos	neg	total
					sen	100%
MRSA Select28 hours	Pos	18	3	21	spec	98%
	Neg	0	179	179	ppv	86%
		18	182	200	npv	100%

STATEMENT OF SAFETY AND EFFICACY:

200 nasal swabs (surveillance samples) were tested on MRSASelect and routine culture (Trypticase Soy Agar w/5% blood, coagulase and susceptibility). Performance of MRSASelect was noted after 18, 20, 24 and 28 hours incubation, comparing results to culture

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results. MRSASelect Sensitivity was 100%, with Specificity at 98% at all incubation time intervals noted. Bio-Rad confirms that any/all data provided in this submission may be released upon request.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/5/Picture/1 description: The image shows the logo for the U.S. Department of Health and Human Services. The logo consists of a circular border with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" arranged around the perimeter. Inside the circle is a stylized image of an eagle or bird-like figure, with its wings represented by a series of curved lines.

Public Health Service

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

JUN 1 8 2008

Bio-Rad c/o Ms. Fran White Regulatory Consultant MDC Associates, LLC 163 Cabot Street Beverly, MA 01915

K081212 Trade/Device Name: Bio- Rad MRSASelect Regulation Number: 21 CFR § 866.1700 Regulation Name: Culture medium for antimicrobial susceptibility test Regulatory Class: Class II Product Code: JSO Dated: April 28th, 2008 Received: April 29th, 2008

Dear Ms. White:

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 udications for use stated in the enclosure) to legally marketed predicate devices marketed in intention 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 Federallions, Or us 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, ilsting of devices, good manufacturing practice, labeling, and prohibitions against misburaniing 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 mourfacturing pratis e 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 advice for your device on our labeling regulation (21 CFR Part 801), please contact the Office of In Vitro Diagnostic Device Evaluation and Safety at 240-276-0450. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding postmarket surveillance, please contact CDRH's Office of Surveillance and Biometric's (OSB's) Division of Postmarket Surveillance at 240-276-3474. For questions regarding the reporting of device adverse events (Medical Device Reporting (MDR)), please contact the Division of Surveillance Systems at 240-276-3464. 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 (240) 276-3150 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours,

Sally attym

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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Bio-Rad MRSASelect Culture Media 510(k) Submission

Indications for Use

510(k) Number (if known):

Device Name:

MRSASelect

R081812

Indications for Use:

Prescription Use X (Part 21 CFR 801 Subpart D)

AND/OR

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

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

Concurrence of CDRH, Office of In Vitro Diagnostic Device Evaluation and Safety (OVD)

Ferdinand Pode

Division Sign-Off Office of In Vitro Diagnostic Device Evaluation and Safety

510(k)

Page 1 of 1

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).