"The health care systems of most European countries are based on a continuum from acute care hospitals, though other health care facilities to the community. Such a framework provides the perfect opportunity for the wide-spread dissemination of high-risk resistant clones or genetic resistant elements. The driving concept of TROCAR is to investigate the fundamentals of the epidemiology of new highly virulent multiresistant strains of methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus spp., Extended-spectrum, metallo- and acquired AmpC beta-lactamase producing Enterobacteriaceae, multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii will focus on three major strategic aims: 1. The definition of the major high-risk resistant clones based on an appropriate representative collection and new clinical strains obtained during molecular epidemiological studies, in hospitals and laboratories collaborating with their respective National Excellence Laboratories in European countries using a standardised protocol. 2. The promotion of collaborative European research to investigate, by genomic and proteomic approaches, specific traits associated with virulence, transmission, persistence and resistance of epidemic clones in comparison with non-epidemic clones as well as resistance determinants and their genetic location in horizontal gene transfer units and their genetic environment. 3. The development of bioinformatics tools to fully exploit the genomics data and allow the rapid identification of resistant strains with heightened epidemic potential. By combining the outputs of the project it will be possible to provide tools for monitoring the spread of key community and nosocomial pathogens, to provide the scientific basis for an early warning system when isolates of a particular epidemicity appear in the community and nosocomial settings, to characterise specific genetic elements carrying resistance genes encoding, and to establish t"