CJIDMM Canadian Journal of Infectious Diseases 1180-2332 Pulsus Group Inc 924761 10.1155/1994/924761 Original Article Molecular Epidemiology of Legionella pneumophila Infection at a Canadian Tertiary Care Institution Nicolle LE Bialkowska-Hobrzanska H Dyck B Sekla L Parker S 1 Section of Infectious Diseases Departments of Medicine and Medical Microbiology University of Manitoba Winnipeg Manitoba Canada umanitoba.ca 2 Infection Control Unit and Clinical Microbiology Laboratory Health Sciences Centre Winnipeg Manitoba Canada hsc.mb.ca 3 Cadham Provincial Laboratory Winnipeg Manitoba Canada gov.mb.ca 4 Department of Microbiology and Infectious Diseases St Joseph’s Health Centre University of Western Ontario London Ontario Canada uwo.ca 5 Department of Microbiology and Immunology University of Western Ontario London Ontario Canada uwo.ca 1994 5 4 157 162 29 6 1993 13 12 1993 1994 Copyright © 1994 Hindawi Publishing Corporation. This open-access article is distributed under the terms of the Creative Commons Attribution Non-Commercial License (CC BY-NC) (http://creativecommons.org/licenses/by-nc/4.0/), which permits reuse, distribution and reproduction of the article, provided that the original work is properly cited and the reuse is restricted to noncommercial purposes.

Objective: To characterize the molecular epidemiology of Legionella species infection at one Canadian tertiary care centre.

Design: Twenty-eight clinical isolates and 12 environmental isolates obtained over a six-year period were analyzed by restriction fragment length polymorphism (rflp) of chromosomal dna. Isolates included 15 from 12 patients with hospital acquired illness and 13 from nine patients with community acquired infection.

Results: One nosocomial strain was Legionella micdadei and one community strain was Legionella pneumophila serotype 6; all others were L pneumophila serotype 1. rflp typing revealed one clone for all cases of a 1985 single-ward outbreak and five of six nonoutbreak L pneumophila nosocomial cases. An rflp pattern identical or highly related to that of the nosocomial clonal type was noted among nine of 12 L pneumophila serotype 1 community isolates. The remaining three isolates had two related rflp patterns distinct from the institutional strain. The nosocomial and community strains were isolated from multiple institutional water samples in the institution. For the environmental isolates, monoclonal antibody typing was more discriminating than rflp typing: seven monoclonal antibody subtypes were distinguished among 12 environmental isolates comprising three distinct rflp patterns.

Conclusions: Despite multiple L pneumophila serotype 1 strains isolated in the authors’ institutional water, a single clone of L pneumophila produced most disease. Community acquired disease was caused by a wider variety of strains.

 Legionella pneumophila Molecular epidemiology Nosocomial infection