Marked increase in incidence of Achromobacter xylosoxidans infections caused by sporadic acquisition from the environment

BackgroundAn increased incidence of Achromobacter xylosoxidans infections has been observed at the Cystic Fibrosis Centre at Aarhus University Hospital, as the proportion of patients colonised with A. xylosoxidans increased from 6 to 10% from 2005 to 2009.MethodsPulsed field gel electrophoresis (PFGE) was used to type isolates of A. xylosoxidans.ResultsFour patients infected for 2–7 years were part of a larger epidemic spread involving both Danish CF centres, while 11 patients carried strains with unique genotypes. Longitudinal analysis of isolates from ten patients with multiple preserved isolates showed that each patient persistently carried isolates of a single genotype. Following lung transplantation, two patients showed re-colonisation of the lung grafts with the pre-transplant A. xylosoxidans strain.ConclusionsA. xylosoxidans has been transmitted between patients from our clinic, but the recent increase in incidence is not caused by cross infections.