Community-acquired Legionnaires' disease caused by Legionella pneumophila serogroup 10 linked to the private home.

We describe the case of a 66-year-old man with a culture-proven Legionella pneumonia after kidney transplantation. The patient developed the infection 15 days after discharge from a university hospital. Legionella pneumonia caused by Legionella pneumophila serogroup 5/10 was established by positive direct fluorescence assay, positive urinary-antigen detection and isolation of the causative agent. The infection was successfully treated by giving appropriate antibiotics, but the further course was complicated by invasive aspergillosis, cytomegalovirus pneumonia, failure of the transplanted kidney and development of septic anaemia. Four months after the diagnosis of Legionella pneumonia the patient died of multi-organ failure. The microbiological and epidemiological investigation revealed that strains from the water supply of the patient's private home were indistinguishable from the patient's isolate by amplified fragment length polymorphism analysis and sequence-based typing (SBT). Unrelated strains of serogroups 4, 5, 8 and 10 from the Dresden strain collection were of different SBT types. Thus, SBT is a very useful tool for epidemiological investigation of infections by L. pneumophila serogroups other than serogroup 1.