Aberdeen chemistry researchers in MRSA discovery

A chemistry team from the University of Aberdeen, working with others in Germany and the USA, have discovered that a protein released from the immune system binds the essential metals of manganese and zinc to combat infection from the hospital super-bug MRSA.

The findings, reported in Science (February 15), supports the notion that binding metals - to starve bacteria - is a viable therapeutic option for treating localised bacterial infections and would make excellent antibiotics. This is urgently needed in particular for MRSA, which has been recognised as the most common cause of hospital-derived infections.

Staphyllococcus is probably one of the most important bacterial pathogens.  If this bacterium develops antibiotic resistance, the traditional treatments are powerless and alternative therapies would be urgently needed.

In order to find new means of treatment, the teams involved in the study investigated how the immune system reacts to Staphyllococcus infection. The aim was to find out whether or not the protein distribution was different in healthy tissue compared to the abscesses produced by the Staphyllococcus infection. 

The University of Aberdeen team, led by Professor Jörg Feldmann from the Department of Chemistry (College of Physical Sciences), became involved in the study by applying their newly developed imaging mass spectrometric technique. This technique does not look at molecules but at the metals using laser ablation ICP mass spectrometry.

Professor Feldmann said: "We examined the liver sections of mice to look at clearly defined areas of infection.  When we overlaid our zinc and manganese maps, we got an absolute match of the pattern. No zinc and manganese could be found in those abscesses of the normal mice, while the rest of the healthy tissue showed the expected 'normal' levels of those essential metals. 

"Analysis of the organs as a whole would not have been able to give us this detailed result, so we had to analyse the liver using metal-imaging technology.  This can be applied to any tissue and for almost all existing elements occurring in samples, even when they are only in minute concentrations. 

"We have used this method in other studies, for example, we mapped arsenic and iodine in sheep horn and could identify how much of these elements were transported from the ewe through the placenta to the unborn lamb," added Professor Feldmann. 

The team of researchers involved in the study included the Vanderbilt University, Nashville, Tennessee, the University of Nebraska Medical Center, Applied Speciation and Consulting in Washington, the University of Münster, in Germany and the University of Aberdeen. 

Professor Feldmann added: "It has been exciting to be a part of such a multi-disciplinary team. The study has brought together researchers from a number of disciplines (microbiology, genetics, pathology, structural biology, immunology, dermatology, and analytical chemistry) to give a new direction for research to combat MRSA and we are proud that we have played a significant role in this study."