Genome sequencing links persistent outbreak of legionellosis in Sydney to an emerging clone of Legionella pneumophila ST211.

Genome sequencing links persistent outbreak of legionellosis in Sydney to an emerging clone of Legionella pneumophila ST211. Appl Environ Microbiol. 2017 Dec 15;: Authors: Timms VJ, Rockett R, Bachmann NL, Martinez E, Wang Q, Chen SC, Jeoffreys N, Howard PJ, Smith A, Adamson S, Gilmour R, Sheppeard V, Sintchenko V Abstract The city of Sydney, Australia, experienced a persistent outbreak of Legionella pneumophila serogroup 1 (Lp1) pneumonia in 2016. To elucidate the source and guide public health actions the genomes of clinical and environmental Lp1 isolates recovered over 7 weeks were examined. A total of 48 isolates from human cases and cooling towers were sequenced and compared using SNP-based, core-genome MLST and pangenome approaches. All three methods confirmed phylogenetic relatedness between isolates associated with outbreaks in the Central Business District (CBD) in March and May and Suburb 1. These isolates were designated "Main cluster" and consisted of isolates from two patients from the CBD March outbreak, one patient and one tower isolate from Suburb 1 and isolates from two cooling towers and three patients from the CDB May outbreak. All main cluster isolates were sequence type (ST)211 which previously has only been reported in Canada. Significantly, pangenome analysis identified mobile genetic elements containing a unique T4ASS that was specific to the main cluster and co-circulating clinical strains, suggesting a poten...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research