CONtrol of COmmunity-acquired MRSA: Rationale and Development of counteractions
(CONCORD)
Grant agreement number: 222718 FP7 HEALTH
Summary
Until recently, methicillin-resistant Staphylococcus aureus (MRSA) were confined to hospitals (HAMRSA). However, community- and farm-associated MRSA (CA- and FA-MRSA) has developed as an important cause of infections. No strategies exist to combat these MRSA. CONCORD is aimed at explaining the ecological success in the community and the farm environment of CA- and FA-MRSA in contrast to HA-MRSA in order to facilitate rationale and development of effective strategies against CA- and FA-MRSA. Epidemiology of CA-MRSA is complex and incomplete. To obtain both a more complete description of the epidemiology of CA-MRSA and recent isolates small scale surveillance will be performed among patients in the 20 most populous EU countries, pig farms in major pig exporting countries and important veal calve raising countries. Genomics data for CA-MRSA are limited and non-existent for FA-MRSA. Successful adaptation of MRSA to a new environment supposes either the acquisition of novel properties or the differential expression of genes already present. Only 2 CA-MRSA have been successfully sequenced and the UMCU has sequenced a FA-MRSA. Whole genome sequencing, comparative genomic hybridization and transcriptomes will be used to understand the genetic adaptations MRSA in the community. The contribution of putative virulence factors to pathogenicity will be studied by knock-outs and complemented strains of these knock-outs. The strains will be tested in in vitro and ex vivo models to establish their physiological role. Mathematical modelling is an important tool to manage infection control. A few models exist that evaluate measures to reduce transmission of HA-MRSA or CA-MRSA in jails. No models are available for FA-MRSA. Modelling will provide both fundamental insights on MRSA epidemiology as well as specific recommendations of testable hypotheses for human and veterinary clinical practice. The potential of intervention strategies to combat CA- and FA-MRSA will be determined.
CONCORD-PILGRIM PRESS RELEASE
A European alliance of scientists confronts the spread of dangerous MRSA strains in the community and livestock
Hospital-acquired MRSA is so well adapted to the hospital that it has difficulty to survive outside the hospital. This is one of the conclusions of a European research project involving an alliance of European scientists.
The alliance conducted this research in collaboration with 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 live-stock. The eradication of MRSA among live-stock 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.
On November 28 and 29 the researchers will present their results on a symposium in Brussels. During that symposium also scientist from the PILGRIM project will present their results. They searched for ways to prevent the spread of MRSA.