Hospital bacterial MRSA strains stay in the hospital
Oeiras, 29.11.11
Hospital-acquired MRSA (Methyclin resistants Staphylocossus aureus) is so well adapted to the hospital that it has difficulty to survive outside the hospital. This is one of the conclusions of a research project involving ITQB and presented this week during the Pilgrim-Concord joint symposium in Brussels, a meeting of researchers involved in two large research consortia who search for ways to prevent the spread of MRSA.
The Lab of Molecular Genetics at ITQB conducted this research integrating a consortium of 8 European research groups from six countries – Denmark, France, Poland, Portugal, the Netherlands, and the UK - in the CONCORD project. The European Union funded the project in 2009 with 3 million euros for 3 years.
MRSA is present in hospitals since the 1960s and since the 1990s also became prevalent in the community and the last years among livestock. MRSA prevalence varies among European hospitals but can reach more than 50% in some intensive care units. The bacterium however did not escape from the hospitals but emerged, amongst others through antibiotic and zinc use, among livestock. The eradication of MRSA among livestock is practically impossible to achieve.
Mathematical models show that the intensive contacts between farms maintains the contamination even when only low levels of the bacterium are present.
The MRSA variant present in hospitals is adapted to the hospital. It is more resistant to antibiotics, but as a consequence grows more slowly. This means that it is difficult to get rid of the bacterium in the hospital, but that it will hardly spread outside the hospital. In contrast the variant in the community is less resistant to antibiotics and grows normally. The research project also showed that MRSA found among livestock differs from both the hospital and community variant.
The bacterium is genetically flexible and has been shown to adapt rather easily to new circumstances. Therefore, MRSA remains a health care threat. A solution is not yet available and prudent use of antibiotics is currently the only option to limit spread as much as possible.
