PhD Defense: Microorganisms and their components present in livestock ambient air in relation to respiratory symptoms


Exposure to livestock farm particulate matter (BioPM) has been shown to have a range of effects to promote or inhibit different facets of allergic respiratory diseases. The main aim of this thesis was to investigate whether microorganism or their components present in indoor ambient air of livestock farms contribute to the initiation and/or worsening of respiratory symptoms in asthmatic patients. We characterized the microbial and fungal profiles of livestock farms BioPM and their effect on innate receptors and cells. The bacterial and fungal communities from livestock airborne BioPM were found to be grouped according to animal farm. BioPM derived from all farms induced a concentration-dependent increase in inflammatory response. The results also show that BioPM from all farms induced the enhancement of an inflammatory response when using blood cells from healthy individuals and asthmatic patients, and it may be related to oxidative stress. However, we found no marked differences in oxidative stress and inflammatory response to BioPM between blood cells from healthy controls and asthmatic patients. We have investigated whether and how BioPM from livetock farms could modify airway allergic responses by using an experimental mouse model as well as the possible underlying mechanisms. The results indicate that inhalation exposure of BioPM from chicken and pig farms may result in enhancement of airway allergic response in mice. All these results indicate the exposure of BioPM from livestock farms may cause the enhancement of airway allergic response. The variation in the responses between farms may be related to the difference in microbial and fungal profiles. Understanding the source and doses of BioPM that may affect the airway allergic response could help susceptible individuals to avoid worsening their respiratory diseases.

Start date and time
End date and time
PhD candidate
D. Liu
Microorganisms and their components present in livestock ambient air in relation to respiratory symptoms
PhD supervisor(s)
prof. dr. F.R. Cassee
prof. dr. G. Folkerts
M.E. Nijland
dr. E. Pinelli Ortiz