At a hospital in Halifax, Nova Scotia, Canada, three strains of Legionella
pneumophila were detectable based on plasmid content, while the isolates co
llected at another hospital in Halifax had no plasmids. Genomic DNA was dig
ested with BssHII, SalI, and SpeI and subjected to pulsed-field gel electro
phoresis (PFGE). We found no relationship between plasmid profile and PFGE
pattern.