title: Total and viable airborne bacterial load in two different agricultural environments using gas chromatography-tandem mass spectrometry and culture: a prototype study.
abstract: Airborne exposure to bacterial components found in agricultural environments can lead to pulmonary inflammation. Total (viable and nonviable) bacterial load was monitored in a stable and a dairy by a new approach, gas chromatography-tandem mass spectrometry measurement of muramic acid, a component of gram positive and gram negative bacterial peptidoglycan. Also used to assess the gram negative bacterial load were 3-hydroxy fatty acids, markers of bacterial lipopolysaccharide. Culture, an established procedure for assessing the viable bacterial portion of airborne dust, served as a basis for comparison. The muramic acid and 3-hydroxy fatty acid concentrations (total C12:0, C14:0, and C16:0) showed a correlation with an R2 of 0.81. Dust and muramic acid levels also correlated. However, although relative muramic acid levels were lower in the stable than the dairy, colony forming units (CFU) were considerably higher in the stable. The total bacterial load (estimated from muramic acid values) for both the stable and dairy was also higher than would have been predicted from culture. These results suggest that nonculture based approaches and culture provide complementary but independent measurements of airborne biopollution.
authors.affiliation: Department of Microbiology & Immunology, University of South Carolina, School of Medicine, Columbia 29208, USA.
authors.forename: M
authors.initials: M
authors.lastname: Krahmer
authors.forename: K
authors.initials: K
authors.lastname: Fox
authors.forename: A
authors.initials: A
authors.lastname: Fox
authors.forename: A
authors.initials: A
authors.lastname: Saraf
authors.forename: L
authors.initials: L
authors.lastname: Larsson
mesh_terms: D000383:Agriculture; D000391:Air Microbiology; D001419:Bacteria / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008070:Lipopolysaccharides / Q000032:analysis; D009112:Muramic Acids / Q000032:analysis; D016272:Occupational Health; D013022:South Carolina
chemical_list: D008070:Lipopolysaccharides; D009112:Muramic Acids