Exposure to bacteria in swine-house dust and acute inflammatory reactions in humans.

Abstract

Inhalation of swine-house dust may cause an acute airway inflammatory condition (organic dust toxic syndrome). Thirty-eight healthy subjects were exposed to swine dust while weighing swine for 3 h. We studied the correlation between acute health effects and the inhaled bacterial exposure markers peptidoglycan (the main constituent of the cell walls of gram-positive bacteria, but also present in lesser amounts in gram-negative bacteria) and lipopolysaccharides (LPS; present only in gram-negative bacteria). LPS activity in airborne dust was measured with the Limulus amebocyte lysate assay (LPS(LAL)), and the total LPS was estimated from 3-hydroxy fatty acids, which were measured with gas chromatography-mass spectrometry (GC-MS) (LPS(GC-MS)). Peptidoglycan was estimated from muramic acid measured with GC-MS. The median (25th to 75th percentile) concentration of inhalable dust was 21 (16 to 25) mg/m3. LPS(LAL) was 1.2 (0.9 to 1.4) microg/m3; LPS(GC-MS) was 3.9 (2.5 to 4.9) microg/m3; and the peptidoglycan concentration in airborne dust was 6.5 (2.7 to 13) microg/m3. All exposure markers correlated significantly with an increase in serum interleukin-6. LPS(LAL) showed the highest correlation (r2 = 0.29) and total inhaled dust the lowest (r2 = 0.09). LPS(LAL) also correlated with symptoms and with an increase in bronchial responsiveness and decrease in vital capacity (VC). Peptidoglycan, but not LPS(LAL), correlated with an increase in the blood granulocyte concentration and in body temperature. The results suggest that several microbial agents in inhaled swine-house dust may contribute to acute systemic health effects.

Heterogeneity in microbial exposure in schools in Sweden, Poland and Jordan revealed by analysis of chemical markers

“…Studies have shown that peptidoglycan is toxic to hamster tracheal epithelium in vitro (Cookson et al, 1989), and this macromolecule also induces reactions that are equivalent to most of the major signs and symptoms associated with bacterial infections, such as fever, leukocytosis, acute-phase responses, and lymphocyte activation (Hauschildt and Kleine, 1995). Furthermore, Zhiping et al (1996) found that the levels of muramic acid (used as a marker of peptidoglycan) in swine-house dust were correlated with granulocyte counts and body temperature in humans who inhaled the dust. Other investigators have reported that dusty indoor environments in schools are associated with adverse health effects (Smedje and Norba¨ck, 2001) and that elevated levels of endotoxin in household surroundings are connected with increased severity of asthma (Michel et al, 1996).…”

Upper airway inflammation and respiratory symptoms in domestic waste collectors

“…The exposure-response relation found was more pronounced for total dust exposure than for endotoxin or glucan exposure alone, suggesting that other currently unidentified agentsfor instance peptidoglycans-in the dust, besides endotoxin and glucan, may also play a part. 35 The availability of repeated exposure and NAL measurements allowed calculation of variance components between and within subjects, where the variance between subjects reflects differences between people and the variance within subjects the day to day variation within a person. Our data showed that between and within subject variability was not the same for each NAL marker, as the total variance for IL6 and total cell concentrations was larger than for IL8 concentrations.…”

Characterization of Bioaerosols from Dairy Barns: Reconstructing the Puzzle of Occupational Respiratory Diseases by Using Molecular Approaches

“…Yet little information on bioaerosols is available. This lack of knowledge impedes the understanding of the bioaerosol-related respiratory diseases etiology (3,18,46). Indeed, the airway mucosa is a primary entry site for toxic and pathogenic factors, but what the workers are exposed to and how it impacts respiratory health are poorly addressed.…”