Isolation and identification of Legionella pneumophila from material reclamation facilities

Sampling points at a material reclamation facility (MRF) were monitored over three months for the presence of Legionella spp. A number of different Legionellae were isolated and typed to identify L. pneumophila serogroup 1, the serotype which is the most common human pathogen. Phenotypic methods resulted in a total of 61 presumptive isolates of Legionella spp. Using latex agglutination, 26 out of the 61 were identified as L. pneumophila serogroup 1, 23 as L. pneumophila serogroups 2-14, and the remaining 12 were Legionella spp. However, on typing using pulse field gel electrophoresis, the 26 L. pneumophila serotype 1 isolates were a diverse group of 25 PFGE types with none persisting in the environment over time. This diversity suggests that there are a number of contamination sources for this important human pathogen in the MRF environment which constitute a risk to health for operatives in these facilities.