Combining Environmental Investigation and a Dual-Analytical Strategy to Isolate the Legionella longbeachae Strain Linked to Two Occupational Cases of Legionellosis

This study reports the strategies used to successfully isolateL. longbeachae strain that was responsible of the two occupational legionellosis in Quebec. Fifteen random samples were collected from the soil of the metal recycling plant where the diagnosed workers were employed, covering 1.5% of the accessible surface of the plant. All samples were analyzed with both the quantitative polymerase chain reaction (qPCR) and culture methods. Four qPCR detection systems targetingLegionella spp,L. pneumophila,L. pneumophila serogroup 1, andL. longbeachae were used. Acid, heat, and acid/heat treatments were used for the culture method. For the qPCR method, all samples were positives forLegionella spp but only four were positives forL. longbeachae. For the culture method, only one isolate could be confirmed to beL. longbeachae. However, that strain proves to be the same one that caused the occupational legionellosis. Detecting the presence ofL. longbeachae using the qPCR method made it possible to target the right samples to enable the cultivable strain ofL. longbeachae to be isolated from the soil of the metal recycling plant. The complementarity of the two methods was established. This paper demonstrated the advantages of selecting the proper sampling and analytical strategies to achieve the isolation of the strain responsible for the infections. It also highlights for the first time in Quebec the potential occupational risks associated withL. longbeachae from soil and should motivate...
Source: Annals of Occupational Hygiene - Category: Occupational Health Source Type: research