← Product Code [JSO](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JSO) · K073027

# SPECTRA MRSA (K073027)

_Thermo Fisher Scientific · JSO · Feb 28, 2008 · Microbiology · SESE_

**Canonical URL:** https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JSO/K073027

## Device Facts

- **Applicant:** Thermo Fisher Scientific
- **Product Code:** [JSO](/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JSO.md)
- **Decision Date:** Feb 28, 2008
- **Decision:** SESE
- **Submission Type:** Traditional
- **Regulation:** 21 CFR 866.1700
- **Device Class:** Class 2
- **Review Panel:** Microbiology

## 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 quide or monitor treatment for infections.

## Device Story

Spectra™ MRSA is a selective/differential chromogenic culture medium for screening nasal MRSA colonization. Input: anterior nares swab specimens. Principle: medium contains antibacterial compounds to inhibit competitor organisms and compounds to induce MRSA phosphatase activity; phosphatase reacts with a novel chromogen to produce denim-blue colonies. Used in healthcare settings by laboratory personnel. Output: visual identification of denim-blue colonies after 24-hour incubation. Healthcare providers use presence of blue colonies to identify MRSA-colonized individuals, facilitating infection control measures. Benefits: rapid screening (24 hours) to support MRSA prevention programs.

## Clinical Evidence

Prospective clinical study of 767 anterior nare specimens across four U.S. regions. Spectra™ MRSA (24h incubation) compared to traditional culture (48h) and susceptibility testing. Sensitivity 95.4% (95% CI 89.6–98.5%), specificity 99.7% (95% CI 98.9–100%), overall agreement 99.1% (95% CI 98.1–99.6%). Positive predictive value 98.1%, negative predictive value 99.2%. Interfering substances (medicinal, transport media, blood, mucous) showed no interference. Reproducibility tested with 20 blinded S. aureus strains.

## Technological Characteristics

Selective/differential chromogenic culture medium. Contains antibiotics/inhibitory agents for non-target organism suppression and chromogenic substrate for phosphatase detection. Form factor: prepared culture medium. Manual reading. No electronic components, software, or energy sources.

## Regulatory 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.

## Submission Summary (Full Text)

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>
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# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY TEMPLATE

A. 510(k) Number:
k073027

B. Purpose for Submission:
Premarket notification

C. Measurand:
Methicillin Resistant *Staphylococcus aureus* (MRSA)

D. Type of Test:
Detection of MRSA using a selective and differential chromogenic media

E. Applicant:
Thermo Fisher Scientific

F. Proprietary and Established Names:
Remel Spectra™ MRSA

G. Regulatory Information:
1. Regulation section:
21 CFR 866.1700
2. Classification:
Class II
3. Product code:
JSO Culture media, Antimicrobial susceptibility test, excluding Mueller Hinton Agar

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4. Panel:
Microbiology

H. Intended Use:

1. Intended use(s):
Remel Spectra™ MRSA 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. Spectra™ MRSA is not intended to diagnose MRSA infection nor to guide or monitor treatment of infection.

2. Indication(s) for use:
Remel Spectra™ MRSA can be used to establish MRSA colonization.

3. Special conditions for use statement(s):
Prescription use

4. Special instrument requirements:
Not applicable

I. Device Description:

Remel Spectra™ MRSA is a selective culture medium that uses chromogenic technology to detect phosphatase activity. Although phosphatase is produced by a wide range of bacteria, including S. aureus, non-target organisms are inhibited by a combination of antibiotics and other inhibitory agents contained in the medium.

In addition to nutrients required for growth and other growth promoting compounds, the medium contains several inhibitory agents to reduce or eliminate non-target organisms. Gram negative bacteria and most commonly encountered yeast and molds are eliminated by the inclusion of antibiotics.

J. Substantial Equivalence Information:

1. Predicate device name(s):
BBL™ CHROMagar™ MRSA

2. Predicate K number(s):

2

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k042812

3. Comparison with predicate:

|  Similarities  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Intended Use | For MRSA detection | For MRSA detection  |
|  Reporting | MRSA | MRSA  |
|  Reading | Manual | Manual  |
|  Test Methodology | selective and differential chromogenic prepared culture medium | selective and differential chromogenic prepared culture medium  |
|  Differences  |   |   |
| --- | --- | --- |
|  Item | Device | Predicate  |
|  Inoculum | Anterior nares culture | Anterior nares  |
|  Incubation | 24 hours | 24 hours, reincubate to 48 hours if negative  |

K. Standard/Guidance Document Referenced (if applicable):

Not applicable

L. Test Principle:

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 enhance the production of the MRSA pathogenicity marker, ensuring expression of the phosphatase enzyme and so providing enhanced sensitivity and specificity.

M. Performance Characteristics (if/when applicable):

1. Analytical performance:

a. Precision/Reproducibility:

Reproducibility was demonstrated at four sites using 20 S. aureus strains including MRSA, MSSA, and borderline oxacillin-resistant S. aureus (BORSA) isolates. Reproducibility was >95%, however, the BORSA strain demonstrated variable results. A limitation has been included in the package insert to address this variability.

b. Linearity/assay reportable range:

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Not applicable

c. Traceability, Stability, Expected values (controls, calibrators, or methods):

The recommended quality control (QC) organisms, S. aureus ATCC 43300 as positive control, and S. aureus ATCC 25923 as negative control were used. QC data was compiled across all four sites and all QC results were acceptable.

d. Detection limit:

Not applicable

e. Analytical specificity:

A Cross Reactivity Study was performed using 280 organisms (MRSA, MSSA, coagulase negative Staphylococci, and other organisms). No cross reactivity was observed when these organisms were tested on the Spectra™ MRSA.

Interference Study

Nine commonly used medicinal substances, human blood, mucous, and six types of transport media were evaluated for potential interference of the chromogenic reaction on the Spectra™ MRSA medium. No interference was observed except for human blood which grew pinpoint denim blue colonies.

f. Assay cut-off:

Not applicable

2. Comparison studies:

a. Method comparison with predicate device:

The Remel Spectra™ MRSA was evaluated at four independent trial sites testing 767 prospective anterior nare surveillance specimens. Results from the Remel Spectra™ MRSA at 24 hour incubation were compared to results obtained from traditional culture on Tryptic Soy Agar with 5% sheep Blood (Blood Agar) after 48 hours incubation. Isolates of S. aureus were identified using a latex agglutination test or a biochemical identification system. Susceptibility testing of S. aureus isolates was performed using an antibiotic gradient method for oxacillin and the Oxoid PBP2' test for detection of the penicillin-binding protein 2a.

Percent agreement with each method as compared to the Remel Spectra™ MRSA is presented in the table below.

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|  Method compared to | % Agreement MRSA | % Agreement MSSA  |
| --- | --- | --- |
|  Traditional Culture | 95.2% (100/105)
(95% CI = 89.6 – 98.5%) | 99.1% (656/662)
(95% CI = 98.9 – 100%)  |
|  Oxacillin MIC | 95.4% (104/109)
(95% CI = 89.6 – 98.5%) | 99.7% (656/658)
(95% CI = 98.9 – 100%)  |
|  PBP2’ | 95.4% (104/109)
(95% CI = 89.6 – 98.5%) | 99.7% (656/658)
(95% CI = 98.9 – 100%)  |

A challenge set of 20 S. aureus isolates which included 15 well-characterized strains of MRSA representing Pulse-Field Types (PFT) USA100, USA200, USA300, USA400, USA500, USA600, USA700, USA800, USA1000, and USA1100; one MRSA, and four MSSA were evaluated on the Remel Spectra™ MRSA and produced expected results.

b. Matrix comparison:
Not Applicable

3. Clinical studies:
a. Clinical Sensitivity:
Not Applicable
b. Clinical specificity:
Not Applicable
c. Other clinical supportive data (when a. and b. are not applicable):
Not Applicable

4. Clinical cut-off:
Not Applicable

5. Expected values/Reference range:
Not Applicable

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N. Proposed Labeling:

The labeling is sufficient and it satisfies the requirements of 21 CFR Part 809.10.

O. Conclusion:

The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

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**Source:** [https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JSO/K073027](https://fda.innolitics.com/submissions/MI/subpart-b%E2%80%94diagnostic-devices/JSO/K073027)

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