Volume 23, Number 11—November 2017
Research
Legionnaires’ Disease Outbreak Caused by Endemic Strain of Legionella pneumophila, New York, New York, USA, 2015
Figure 3

Figure 3. Minimum spanning tree of 77 isolates related to the 2015 South Bronx Legionnaires’ disease outbreak caused by an endemic strain of Legionella pneumophila, New York City, New York, USA, 2015. The tree was created by using single-nucleotide polymorphism (SNP) differences found across all isolates. Sizes of circles are proportional to number of isolates having identical genomic backgrounds, numbers adjacent to lines indicate number of polymorphism differences between each node, and numbers in parentheses indicate years. Strains 07-304 and 15-215 contain the same plasmid and differ greatly from the plasmid present in all East Bronx isolates. These plasmids have only partial identity with known plasmids in other Legionellaceae. *East Bronx outbreak samples contain 1,030 additional SNP differences caused by the presence of suspected homologous recombination events that were omitted from the final SNP analysis; †Plasmids are present in these isolates. EBC, East Bronx college; env., environmental; HS, homeless shelter; NH, nursing home.