MRSASelect™ is a selective and differential chromogenic medium for the qualitative detection of methicillin resistant Staphylococcus aureus (MRSA) from skin and soft-tissue wound specimens. The MRSASelect™ is indicated for use in conjunction with other laboratory tests and clinical data available to aid in the identification and diagnosis of MRSA from patients with skin and soft-tissue infections. Concomitant cultures and susceptibility testing are necessary for all skin and soft-tissue wound specimens. MRSASelect™ is not intended to guide, or monitor treatment for MRSA infection, or provides results of susceptibility to methicillin. Results can be interpreted after 18 to 28 hours incubation.

Device Description

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

AI/ML Overview

The provided document describes the Bio-Rad MRSASelect - Wound Specimens, a chromogenic medium for detecting methicillin-resistant Staphylococcus aureus (MRSA) from skin and soft-tissue wound specimens.

Here's an analysis based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance:

The document does not explicitly state "acceptance criteria" as distinct numerical targets. However, based on the performance data presented, the implicit acceptance criteria would be the measured specificity and sensitivity values.

Performance Metric	Acceptance Criteria (Implicit from Study Results)	Reported Device Performance
Specificity	N/A (Expected to be high)	99.4% (95% CI: [98.5, 99.8])
Sensitivity	N/A (Expected to be high)	91.7% (95% CI: [87.3, 94.7])
Overall Agreement	N/A (Expected to be high)	97.6% (95% CI: [96.3, 98.4])
Reproducibility	N/A (Expected to be high)	100%
Cross-reactivity	No cross-reactivity expected	Not observed

2. Sample size used for the test set and the data provenance:

Sample Size for Test Set: 943 clinical skin and soft-tissue wound samples.
Data Provenance: The samples were collected and tested at four clinical laboratories in the United States. The study is prospective in the sense that samples were collected and tested for the purpose of this evaluation, but the clinical context (e.g., patient demographics, recruitment methods) typical of a detailed prospective study are not fully elaborated.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:

The document does not specify the number of experts or their qualifications used to establish the ground truth for the clinical test set. It mentions "routine culture and identification" as the comparator method.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set:

The document does not describe an adjudication method for disagreements, as it relies on a "routine culture and identification" method as the comparator. The ground truth was established by confirming positive samples from TSA or TSB with Gram stain, Pastorex™ Staph Plus, and mecA mediated oxacillin resistance using a Cefoxitin disk.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance:

This device is a culture medium, not an AI-assisted diagnostic tool. Therefore, an MRMC comparative effectiveness study was not performed, and the concept of "human readers improving with AI assistance" does not apply.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:

The device is a culture medium that provides a qualitative visual result (pink colonies for MRSA). While human interpretation is involved in reading the results, the performance data presented (specificity, sensitivity) represents the standalone performance of the medium in detecting MRSA from samples, with a human interpreting the outcome. There is no "algorithm" involved in the sense of an AI model.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):

The ground truth for the clinical study (Method Comparison) was established by a combination of standard microbiological methods, referred to as "Routine Culture & TSB." This involved:

Trypticase Soy Agar (TSA) with 5% Sheep's Blood
Tryptic Soy Broth (TSB) with 6.5% NaCl
Confirmation of positive samples with Gram stain, Pastorex™ Staph Plus, and mecA mediated oxacillin resistance using a 30 ug/mL Cefoxitin disk.

8. The sample size for the training set:

The document does not mention a separate "training set" as this is a traditional diagnostic medium validation, not an AI model development. However, several analytical studies were performed:

Interfering Substances: Samples of common topical agents inoculated with MRSA.
Cross-Reactivity Testing: 35 bacterial and fungal strains.
Analytical Sensitivity: 102 strains of MRSA (including USA100, 200, 300, 500, 600, and 1000).
Reproducibility: A panel of 6 organisms (MRSA, MSSA, S. epidermidis).

9. How the ground truth for the training set was established:

For the analytical studies (which could be considered analogous to internal validation or characterization):

Interfering Substances: Ground truth was based on expected growth/inhibition of known MRSA strains in the presence of various agents.
Cross-Reactivity Testing: Ground truth was based on the known identity of the 35 bacterial and fungal strains inoculated.
Analytical Sensitivity: Ground truth was based on the known identity and concentration of the 102 characterized MRSA strains used.
Reproducibility: Ground truth was based on the known identity of the 6 organisms in the panel.

Summary

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October 21, 2010 Page 39 of 42

510(k) SUMMARY

OCT 2 9 2010

Date of Summary	October 21, 2010
Product Name	Bio-Rad MRSASelect -- Wound SpecimensA selective and differential chromogenic medium for thequalitative detection of methicillin-resistant Staphylococcus aureusfrom skin and soft-tissue wound specimens. Results can beinterpreted after 18 - 28 hours incubation.
Sponsor	Bio-Rad3 Boulevard Raymond Poincaré92430 Marnes-la-CoquetteFrance
Correspondent	MDC Associates, LLCFran White, Regulatory Consultant180 Cabot StreetBeverly, MA 01915

Substantially Equivalent Device

MRSASelect for skin and soft-tissue wounds is substantially equivalent to Bio-Rad MRSASelect extended incubation (reference 510(k) K081212). Products are thromogenic media used for the detection of MRSA direct from a specimen swab.

Manufacturer: Bio-Rad MRSASelect -- extended incubation Product:

Product Attribute	Bio-Rad MRSASelect™Extended Incubation	Bio-Rad MRSASelect™Wound Specimen
Intended use	MRSASelect is a selective anddifferential chromogenic mediumfor the qualitative detection ofMRSA direct from a nasal swabfor the detection of methicillinresistant Staphylococcus aureus(MRSA).	MRSASelect is a selective and differentialchromogenic medium for thequalitative detection of methicillin resistantStaphylococcus aureus (MRSA) from skinand soft-tissue wound specimens.
Product format	Chromogenic agar	Chromogenic Agar
Read time	After 18-24 hour incubation	After 18-24 hours incubation
Quality Control	Daily with recommended	Daily - same recommended organisms

Similarities

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	organisms
	Differences
Product Attribute	Bio-Rad MRSASelect™ Extended Incubation	Bio-Rad MRSASelect™ Wound Specimen
Intended use	MRSASelect is a screen for the detection of colonization of methicillin resistant Staphylococcus aureus (MRSA) to aid in the prevention and control of MRSA infections in healthcare settings.	MRSASelect is indicated for use in conjunction with other laboratory tests and clinical data available to aid in the identification and diagnosis of MRSA from patients with skin and soft-tissue infections. Concomitant cultures and susceptibility testing are necessary for all skin and soft-tissue wound specimens. MRSASelect™ is not intended to guide, or monitor treatment for MRSA infection, or provides results of susceptibility to methicillin.

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

Intended Use

MIRSASelect™ is a selective and differential chromogenic medium for the qualitative detection of methicillin resistant Staphylococcus aureus (MRSA) from skin and soft-tissue wound specimens. The MRSASelect™ is indicated for use in conjunction with other laboratory tests and clinical data available to aid in the identification and diagnosis of MRSA from patients with skin and soft-tissue infections. Concomitant cultures and susceptibility testing are necessary for all skin and soft-tissue wound specimens. MRSASelect™ is not intended to guide, or monitor treatment for MRSA infection, or provides results of susceptibility to methicillin. Results can be interpreted after 18 to 28 hours incubation.

Summary of Technology

MRSASelect is a selective and differential chromogenic medium for the qualitative detection of methicillin resistant Staphylocccus aureus (MRSA) from skin and soft-tissue wound specimens. The selectivity of this medium is based on the presence of an antibiotic/antifungal mixture and an optimized salt concentration 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

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October 21, 2010 Page 41 of 42

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

Interfering Substances

In order to evaluate the possible interference of common topical agents used in wound care samples of these agents were inoculated with MRSA and plated on MRSASelect media. Use of the following compounds has an inhibitory effect on MRSA growth that is unrelated to medium performance:

Bactine (Benzalkonium chloride 0.13%. Lidocaine hydrochloride 2.5%); Betadine (liquid) (Povidoneiodine 10%), Iodine Tincture (liquid) (Iodine 2%), Biseptine (liquid) (Chlorhexidine Gluconate 0.25%, Benzalkonium chloride 0.025%), Sodium hypochlorite (liquid), StaphAseptic (ointment) (Benzethonium Chloride 0.2%, Lidocaine HCl 2.5%), and silver chloride.

Cross Reactivity Testing (Analytical Specificity)

To evaluate the analytical specificity of the MRSASelect™ media 35 bacterial and fungal strains found in wound or skin samples were cultured and inoculated onto MRSASelect™ plates at a concentration of ≥10° CFU/mL.

No cross-reactivity was observed on any strains tested. Most strains showed no growth on MRSASelect™ with the exception of Corynebacterium jeikeium and Candida tropicalis. With both of these organisms pinpoint white colonies were observed: these are not representative of MRSA colonies, and therefore these are not cross-reactants. No variation was seen between 24 and 28 hour incubation time.

Analytical Sensitivity To evaluate the analytical sensitivity of the MRSASElect™, 102 strains of MRSA, including USA100, 200, 300, 500, 600, and 1000 were inoculated onto MRSASelect™ plates at concentrations of 10 to 10 CFU/mL. USA300-0114 was also tested. 97% (99/102) sensitivity was observed after 24 hours incubation.

Reproducibility

A panel of 6 organisms, including MRSA, MSSA and S. epidermidis, was evaluated on MRSASelect™. It was performed at concentrations of 108 CFU/mL for MRSA, and 108 CFU/mL for non-MRSA. The panel was tested in triplicate each day for three clinical sites. Overall reproducibility was 100% after 24 hours incubation when testing this panel.

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Method Comparison

943 skin and soft-tissue wound samples were collected and tested at four clinical laboratories in the United States. Each sample was tested on MRSASelect™, Trypticase Soy Agar (TSA) with 5% Sheep's Blood, and Tryptic Soy Broth (TSB) with 6.5% NaCl. Samples that were positive on TSA or TSB were confirmed with Gram stain, Pastorex™ Staph Plus, and mecA mediated oxacillin resistance using 30 ug/mL Cefoxitin disk (R: ≤21 mm, S: ≥ 22 mm)

The following results were obtained: specificity 99.4% (95% CI: [98.5, 99.8]) and sensitivity 91.7% (95% CI: [87.3, 94.7}). The overall prevalence of MRSA in the study was 24.2% (95% CI: [21.5, 27.0]). MRSASelect™ vs. Routine Culture and TSB

		Routine Culture&TSB
		Pos	neg	total
MRSA	pos	209	4	213
Select™	neg	19*	711	730
	total	228	715	943

For 12/19 samples - MRSA were isolated only from TSB with 6.5% NaCl and were not isolated on initial direct culture.

99.4% [98.5, 99.8] Overall % agreement 97.6% [96.3, 98.4] Specificity Sensitivity 91.7% [87.3, 94.7]

Statement of Safety and Efficacy

The data presented demonstrates the safety and efficacy of the Bio-Rad MRSASelect™ as compared to routine culture and identification when results are interpreted after 18 to 28 hours incubation in ambient air.

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DEPARTMENT OF HEALTH & HUMAN SERVICES

Image /page/4/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a stylized caduceus symbol, which is a staff with two snakes entwined around it, and the text "DEPARTMENT OF HEALTH & HUMAN SERVICES (USA)" arranged in a circular fashion around the symbol. The text is in all caps and is evenly spaced around the circle.

Food and Drug Administration 10903 New Hampshire Avenue Document Mail Center - WO66-0609 Silver Spring, MD 20993-0002

BIO-RAD c/o MDC Associates, LLC 180 Cabot Street Beverly, Massachusetts 01915 Attn: Fran White

OCT 2 9 2010

Re: K100589

Trade/Device Name: MRSASelect
Regulation Number: 21 CFR §866.1700
Regulation Name: Culture medium for antimicrobial susceptibility tests
Regulatory Class: Class II
Product Code: JSO
Dated: October 21, 2010
Received: October 25, 2010

Dear Ms. White:

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. Ilsting 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 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 Part 801); medical device 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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Page 2 - Ms. Fran White

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm11.5809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 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 Small Manufacturers, International and Consumer Assistance 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,

Ledale hi-Poole, Ms
day

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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October 21, 2010 Page 37 of 42

OCT 2 9 2010

Indications for Use

510(k) Number (if known): K100589

Device Name: MRSASelect

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)

Leedole. Podo, M.S.

Division Sign Off

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

KI66585 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).