Date of Award

2013

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

First Advisor

Waterman, Jenora T.

Abstract

Agriculture workers inhale a variety of dusts, gases, microbes and compounds on a daily basis. Several respiratory diseases display inflammation and oxidative stress as key factors of pathogenesis. To better understand the effects of agricultural dusts on the airway there first needs to be characterization of dust components. Thus, we hypothesized that confinement facilities contain high levels of respirable particles, bacteria, and elements of respiratory importance. We further hypothesized that SCF dust alone or in combination with diepoxybutane (DEB) will result in oxidative stress and phytonutrients from the sorrel plant will reduce these effects. Several bacterial species were identified via amplification of the 16S ribosomal DNA gene and or biochemical selection, and include Escherichia coli, Listeria sp., Bacillus sp., Staphylococcus and Clostridium species. Each dust extract showed pH altering effects (p-value < 0.05) and resulted in acidic changes with the exception of small ruminant dust (alkaline). Respirable particles (< 10 μm) were found in dairy and poultry dusts. More inhalable particles were found in swine, small ruminant and equine dust samples. Exposure to swine dust extract increased intracellular hydrogen peroxide, 8-isoprostane and nitric oxide levels in NHBE cells in vitro and pretreatment with sorrel prevented such increases (p-value<0.001, p-value<0.001 and p-value<0.05 respectively). Elucidating the mechanism of agricultural dust mediated oxidative stress, ‘dust+DEB’ mediated oxidative stress and agriculture-related inflammatory airway diseases will provide insight for better understanding of respiratory diseases caused by chronic exposure to CAFO-like facilities and development of improved animal management practices to ultimately decrease the incidences of respiratory disease.

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