The presence of a specific genotype of Legionella pneumophila serogroup 1 in a hospital and municipal water distribution system over a 12-year period.
The genotypic distribution of Legionella pneumophila serogroup 1 was investigated in the water distribution system of a 450-bed Swedish hospital and the surrounding community. A single genotype identified by amplified fragment length polymorphism (AFLP) analysis, was found in all 34 hospital isolates and in 18 out of 20 community isolates over a 12-y surveillance period. All isolates were either monoclonal antibody subtypes Benidorm or Bellingham. In a geographical comparison, the hospital genotype was also identified in 2 out of 6 Swedish hospitals, both located within 100 km of the studied community. In all, 70 isolates originating from 7 Swedish communities clustered in 4 groups, each also containing 1 AFLP type as defined by the European Working Group on Legionella Infections (EWGLI). It was concluded that a single Legionella pneumophila serogroup 1 genotype may colonize a large water distribution system over a long period of time, and that certain clones seem to be widely spread in the environment. Results from molecular typing of isolates originating from a limited geographical area must, therefore, be interpreted cautiously in epidemiological investigations of Legionnaires' disease.
Darelid
Johan
J
Department of Infectious Diseases, Ryhov Hospital, S-55185 Jönköping, Sweden. johan.darelid@lj.se
Bernander
Sverker
S
Jacobson
Kerstin
K
Löfgren
Sture
S
D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D005060:Europe / Q000453:epidemiology; D006745:Hospital Bed Capacity, 300 to 499; D006761:Hospitals; D006801:Humans; D016952:Legionella pneumophila / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D007877:Legionnaires' Disease / Q000453:epidemiology* / Q000382:microbiology; D012150:Polymorphism, Restriction Fragment Length; D013548:Sweden / Q000453:epidemiology; D014871:Water Microbiology; D014881:Water Supply
D004269:DNA, Bacterial