Genomic Investigation of a Legionellosis Outbreak in a Persistently Colonized Hotel.

Objectives: A long-lasting legionellosis outbreak was reported between November 2011 and July 2012 in a hotel in Calpe (Spain) affecting 44 patients including six deaths. Intensive epidemiological and microbiological investigations were performed in order to detect the reservoirs.

Methods: Clinical and environmental samples were tested for the presence and genetic characterization of Legionella pneumophila.

Phylogenetic analysis of environmental Legionella pneumophila isolates from an endemic area (Alcoy, Spain).

Environmental surveillance of Legionella pneumophila is a key component of the control measures established in urban settlements to ensure water safety and quality, with the aim of minimizing and limiting opportunistic infections in humans. In this work, we present results on the detection and genetic characterization of these bacteria in the outbreak-recurrent region of Alcoy (Comunidad Valenciana, Spain) using water and biofilm samples. We were particularly interested in studying the presence and distribution of L.