Bioaerosols containing Legionella may cause Legionnaires’ disease and Pontiac fever in humans. Legionella occur in natural and artificial water systems and are ubiquitous therein. Infection of humans is only caused by inhaling bioaerosols containing these bacteria. Those bioaerosols are, for example, generated by hot water systems, air-conditioning systems, while showering or by cooling towers and can be a threat for the health of people in surrounding areas. Rapid detection methods are essential to combine sampling of bioaerosols with multiplexed analysis for specification and quantification of Legionella species in air. The rapid quantification of bacteria with flow-through chemiluminescence microarrays was established in our laboratories and is applied for bioaerosol analysis in this work .
The efficiency of bioaerosol sampling with Coriolis μ was examined by nebulizing living E. coli in a chamber and quantifying them with flow cytometry after sampling. A recovery of 34±10% was found with a high reproducibility between 5×105 and 2×107 cells/mL. The impinger AGI-30 was compared to the cyclone separator Coriolis μ by quantification of collected L. pneumophila with microarray sandwich immunoassay analysis (Fig.1).
Similar recoveries were determined for both samplers (Fig.2). However, the detection limit with Coriolis μ was lower by a factor of 100 due to the higher sampling rate.