Investigation of an OXA-436 carbapenemase outbreak: when everything goes down the drain.

Over a time period of 18 months an sequence type (ST) 90, harboring a carbapenemase gene, was isolated from seven patients at Odense University Hospital, Denmark. The patients were all from the same department, but there was no apparent direct epidemiological link. Whole genome sequencing (WGS) was performed on all clinical isolates as well as on a number of environmental samples including two ST90 isolates carrying the gene, which were isolated in samples from two shower drains at the department. These drains were suspected to be the source of the outbreak.