ABSTRACT: Characteristics of bacterial bioaerosols at Toyama and Yokohama in Japan as assessed by eight-stage Andersen sampler and Illumina MiSeq sequencing
Project description:Legionnaire’s Disease is a growing concern for the United States and Europe, with disease incidences rising 6-fold since 2002. These recorded cases are increasingly associated with antibiotic resistant Legionella pneumophila, the causative agent of Legionnaire’s Disease and overall Legionellosis. With this, the need to study L. pneumophilainfections has never been greater. Current methodology for Legionella pneumophila infection studies often revolves around either artificial administration using intranasal or intratracheal delivery, semi-authentic delivery using bioaerosols and individual delivery systems (i.e. nose cones), or the burgeoning field of authentic exposure scenarios using aerosol generating showerhead devices. Here, we developed an alternative method using a Madison Aerosol Chamber as a means of generating and delivering bioaerosols in mice. We show that bioaerosol delivery using the Aerosol Exposure Chamber is very effective at exposing mice to various doses of L. pneumophila. RNASeq analyses revealed a robust immune response to bioaerosol delivered L. pneumophila comprising of activations of classical markers of infection and inflammation, including Cxcl and Ccl family genes and Il-1β. Similar gene expression profiles were observed when animals were intranasally exposed to L. pneumophila. Intranasal delivery resulted in a shorter duration of activation of several genes, indicating a lack of realistic infection response. Taken together, this evidence shows that our system delivers similar, if not better, results than intranasal inoculation while allowing researchers to study bioaerosol generation and delivery mechanisms simultaneously, critical factors for studying Legionella pneumophila infection. Such a new approach will allow for more accurate investigations to understand the effects of inhaling to Legionella contaminated drinking water.
