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

Abstract

Background Although 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. Objective The objective of this study was to directly compare bacteria, both quantitatively and qualitatively, in bioaerosols from CH and FH poultry facilities. Methods Bioaerosols 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). Results Dust ( 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. Conclusions Bacteria concentration and diversity are significantly different between bioaerosols from CH and FH poultry operations.