Full Force deliverable. This task objective is to investigate the spread of ESBL-producing Enterobacteriaceae in horses in Europe. The focus will be on blaCTX-M-1 and blaSHV-12 genes. To date, isolates carrying blaCTX-M-1 predominate in horses. This is due to clonal dissemination as well as the spread of closely-related IncHI1 plasmids. The success of this plasmid gene combination might be due to the fact that the IncHI1 plasmid also carries the fos-operon, involved in the metabolism of fructo-oligosaccharides, which could give the plasmid a selective advantage in the gut of the horse. The combination IncHI1+ blaCTX-M-1 appears to be almost exclusively linked to horses. Less is known of the epidemiology of blaSHV-12, which is often associated with IncX3-plasmids. In total around 200 isolates from horses, both commensals and clinical isolates, from different parts of Europe will be included to investigate clonal and horizontal transmission. The inventory of available isolates among participanting partners is completed (n=264). All short-read sequences have been uploaded to owncloud, raw reads are assembled and the plasmidome determined/filtered. The plasmidome is comprised out of 8 clusters.