Subtyping Keyvisual

Staphylococcus aureus subtyping for MRSA detection

Methicillin resistant Staphylococcus aureus (MRSA) is resistant to beta-lactam antibiotics and is one of the most frequent causes of antibiotic resistant infections worldwide. It’s estimated that in the European Union alone annually more than 150,000 patients are infected with MRSA.

MRSA is a serious hazard

MRSA infections can be serious and cause sepsis, pneumonia, organ damage and scarring due to necessary surgery. MRSA is especially troublesome in hospitals, nursing homes and other facilities where immunocompromised patients with open wounds or invasive devices are at great risk of nosocomial infections. MRSA mediated pneumonia and sepsis have high death rates. And, because of the use of antibiotics to treat the infection, MRSA patients have the risk to get a secondary infection with C. difficile which they may not survive.

Quick detection of PSM-mec carrying MRSA

A part of MRSA strains produces a phenol-soluble moduline (PSM-mec) which is a staphylococcal toxin.
This coupling of a toxin with antibiotic resistance genes allows a simultaneous species identification and MRSA positivity warning by detection of a PSM-mec specific signal in mass spectra. Prerequisite for the detection is the successful identification of Staph. aureus in the MBT identification workflow. The MBT Subtyping Module looks then automatically for detection of the PSM-mec peak.

Staphyloccocus aureus
Staphyloccocus aureus

An early warning system

The proportion of MRSA with PSM-mec is variable, depending on regional epidemiology. Germany for example has a high proportion of MRSA with PSM-mec whereas within the USA it is low. Absence of this peak does not mean that the respective strain is not an MRSA so that additional confirmation methods are required; but if detected, it is MRSA.

The MBT Subtyping Module detects also blaKPC expressing Klebsiella pneumoniae and cfiA positive B. fragilis strains.



Not for use in clinical diagnostic procedures.