Bacterial diversity characterization of bioaerosols from cage-housed and floor-housed poultry operations

BackgroundAlthough bioaerosols from both cage-housed (CH) and floor-housed (FH) poultry operations are highly concentrated, workers from CH operations have reported a greater prevalence of respiratory symptoms.ObjectiveThe objective of this study was to directly compare bacteria, both quantitatively and qualitatively, in bioaerosols from CH and FH poultry facilities.MethodsBioaerosols were collected from fifteen CH and fifteen FH poultry operations, using stationary area samplers as well as personal sampling devices. Dust, endotoxin and bacteria were quantified and bacterial diversity was investigated using PCR followed by denaturing gradient gel electrophoresis (DGGE).ResultsDust (p<0.001), endotoxin (p<0.05) and bacteria (p<0.05) were significantly higher in personal bioaerosols of FH poultry operations than CH bioaerosols. Although dust and endotoxin did not differ significantly between area and personal samples within each barn type, clustering analysis of DGGE profiles of bacteria revealed that area and personal samples shared less than 10% similarity. These data suggest that area samples are not representative of personal bacteria exposures, which may be affected by worker movement, bacteria carried on the worker and worker location. Personal DGGE profiles from CH and FH operations shared less than 20% similarity and composite analysis showed that bacteria were more prevalent in personal samples from CH bioaerosols than FH bioaerosols.ConclusionsBacteria concentration and diversity are significantly different between bioaerosols from CH and FH poultry operations.

Research highlights
► Dust, endotoxin and bacteria were higher in FH than CH bioaerosols.
► Area and personal DGGE profiles shared less than 10% similarity.
► Personal CH and FH DGGE profiles shared less than 20% similarity.
► Bacteria were more prevalent in personal CH than FH bioaerosols.