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    cobas® MRSA/SA Test

    Faster than a spreading infection

An effective MRSA/SA 
screening program uses rapid techniques


Method sensitivity and time-to-result are critical factors contributing to the success of a screening program for Staphylococcus aureus (SA) and methicillin-resistant Staphylococcus aureus (MRSA) infections. Time delays associated with incubation of conventional culture-based methods can delay implementation of infection control measures, requiring more general infection control measures to be used for all patients, providing opportunities for transmission. Active surveillance to identify MRSA/SA carriers is helping to mitigate the potential consequences of disease, providing relief to patients and health care institutions facing the challenges of escalating costs. 

Only rapid techniques, such as the cobas® MRSA/SA Test, enable early detection of MRSA and SA in colonized patients leading to rapid implementation of appropriate barrier precautions. The test offers microbiology labs an innovative assay that detects both organisms from a single nasal swab specimen, providing time-saving efficiencies through primary sample vial loading for lifesaving answers.


“Circumventing the traditional ‘culture and subsequent identification’ procedures in medical microbiology, molecular testing provides unrivaled speed to result for MRSA and C. diff colonization and/or infection.
Depending on the local infrastructure, same-day results are within reach. So clinicians can initiate appropriate isolation measures or effective antibiotic eradication schemes without delay—for the benefit of both the affected patient and the contact persons.”

Dr. Professor Dr. Udo Reischl

Professor Dr. Udo Reischl,

Institute of Medical Microbiology and Hygiene University Hospital Regensburg

The cobas® MRSA/SA Test detects both targets to deliver high quality results

Test Overview


Performance of the cobas® MRSA/SA Test compared to direct and enrichment culture

Exceptional performance for effective MRSA surveillance

The cobas® MRSA/SA Test is a fast, effective, and efficient way to test for both MRSA and SA in patient samples. 

The cobas® MRSA/SA Test:

  • Quickly identifies colonized patients to enable decisive action
  • Provides the sensitivity and specificity that only polymerase chain reaction (PCR) technology can deliver
  • Simplifies data interpretation with patented, state-of-the-art software algorithms
  • Adds to the expanded test menu on the cobas® 4800 System, which also includes Clostridium difficile (C. difficile) testing 

Test Performance

Get the sensitivity and specificity that only PCR can offer

When compared to a CE-marked and FDA-cleared nucleic acid amplification test (NAAT), the cobas® MRSA/SA Test demonstrated the following sensitivity, specificity, positive predictive values, and negative predictive values: 

*Performance comparison in a study of 379 samples.
Sensitivity 93%
Specificity 99%
Positive Predictive Value 85%
Negative Predictive Value 99%
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Sensitivity 94%
Specificity 97%
Positive Predictive Value 96%
Negative Predictive Value 96%

*Performance comparison in a study of 379 samples.

Deliver high-quality results in a matter of hours with the cobas® MRSA/SA Test

Sample Preparation

Less hands-on time means more walk-away time and reduced chance of error

The cobas® MRSA/SA Test saves time with first-of-its-kind primary vial loading. Using the MSwab™ system, specimens collected on a FLOQSwab™ are transferred directly into the primary vial for testing. The MSwab system is optimized for molecular and culture applications. 

Labs can run 4 to 5 small runs or 2 high-volume runs for up to 194 results/day.



Hands-on Time

Run specimens with automated efficiency

Running on the cobas® 4800 System, the cobas® MRSA/SA Test can process specimens using one of the fastest, most advanced real-time PCR amplification and detection methods available today. The cobas® MRSA/SA Test requires up to 93% less hands-on time compared to other molecular tests for 94 samples. 

Mixed Batch Testing

Run mixed batch assays

The cobas® 4800 System offers flexibility with parallel sample processing capabilities. cobas® MRSA/SA Test samples can be run with different tests and sample types in one run. 

Run mixed batch assays of: 

  • Nasal (cobas® MRSA/SA Test) 
  • Stool (cobas®  Cdiff Test) 
  • Anogenital lesions (cobas® HSV 1 and 2 Test)


In addition to parallel sample processing, the cobas® 4800 System offers an expanding test menu.  


Learn about the system ›




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cobas® MRSA/SA Assay Performance and Specifications 
Sample Type Nasal Swab Specimen
Sample Processing Primary vial loading with MSwab System directly on the cobas® 4800 System 
Sample Versatility  Molecular or culture capability 
Contamination Control AmpErase
PCR Target Region  MRSA: Right Extremity (RE) Junction 
Analytical Sensitivity 99% diverse global panel (n=292)
Analytical Specificity  100% No cross reactivity observed of 118 closely related or normal flora organisms
SCCmec Coverage  I, II, III, IV, IVa, V, VI, VIII
Clinical Sensitivity* MRSA: 93% SA: 95%
Clinical Specificity*  MRSA: 98% SA: 95%
Inhibition Rate  <0.1%
Workflow  Mixed batch capability; up to 4 runs in a single shift

*Compared with direct culture cytotoxicity test 

Intended Use: The cobas® MRSA/SA Test on the cobas® 4800 System is an automated, qualitative, in vitro diagnostic test, that utilizes real-time polymerase chain reaction (PCR), for the direct detection of methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus(SA) DNA from nasal swabs to aid in the prevention and control of MRSA and SA infections in healthcare settings. The cobas MRSA/SA Test is not intended to diagnose, guide or monitor treatment for MRSA or SA infections, or provide results of susceptibility to methicillin. Concomitant cultures are necessary only to recover organisms for epidemiology typing or for further susceptibility testing.

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