Laboratory for Bacterial Evolution and Pathogenesis (LBEP)

High population diversity found in Legionella longbeachae

Genomic analyses highlight the complexities of tracing the origin of legionellosis

Our PhD student Rodrigo Bacigalupe just published his first first-author article, "Population Genomics of Legionella longbeachae and Hidden Complexities of Infection Source Attribution", in the Emerging Infectious Diseases journal. Congratulations, Rodrigo! This is the article abstract:

Legionella longbeachae is the primary cause of legionellosis in Australasia and Southeast Asia and an emerging pathogen in Europe and the United States; however, our understanding of the population diversity of L. longbeachae from patient and environmental sources is limited. We analyzed the genomes of 64 L. longbeachae isolates, of which 29 were from a cluster of legionellosis cases linked to commercial growing media in Scotland in 2013 and 35 were non-outbreak-associated isolates from Scotland and other countries. We identified extensive genetic diversity across the L. longbeachae species, associated with intraspecies and interspecies gene flow, and a wide geographic distribution of closely related genotypes. Of note, we observed a highly diverse pool of L. longbeachae genotypes within compost samples that precluded the genetic establishment of an infection source. These data represent a view of the genomic diversity of L. longbeachae that will inform strategies for investigating future outbreaks.

For more information, you can find the article here.

Full citation: 

Bacigalupe R, Lindsay D, Edwards G, Fitzgerald JR. Population Genomics of Legionella longbeachae and Hidden Complexities of Infection Source Attribution. Emerg Infect Dis. 2017 May;23(5):750-757. doi: 10.3201/eid2305.161165.