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.