Characterization of Bioaerosols from Cage-housed and Floor-housed Poultry Operations

Background. Dust and endotoxin levels are higher in bioaerosols from floor-housed (FH) poultry operations than cage-housed (CH) poultry facilities. Workers from CH operations have reported a greater prevalence of respiratory symptoms than FH workers. The negative respiratory symptoms observed in workers are typically attributed to endotoxin. However, other components of poultry bioaerosols and their effects on human health, such as bacteria, antibiotics and archaea, are poorly understood. Bacteria have been detected in intestinal, fecal, litter, and air samples from poultry operations. Chicken fecal bacteria differ depending on bird age and antibiotic use, which differ between CH and FH facilities. Antibiotics are used in CH and FH poultry operations to lower the likeliness of disease transmission. In FH facilities, antibiotics may also be used at sub-therapeutic levels for growth promotion. Low levels of antibiotic create a selective pressure towards antimicrobial resistance (AMR) in chicken fecal bacteria. Archaea have been detected in ceca, fecal, litter and house fly samples from poultry facilities but have not been investigated in bioaerosols. However, archaea have been detected in swine and dairy bioaerosols and can induce airway inflammation. Further understanding of poultry bioaerosols, with a comparison of those from CH and FH operations, will aid in the development of management practices to reduce worker exposure and response. Objective. The objective of these studies was to compare bioaerosols from CH and FH poultry facilities. Specifically, levels of dust, endotoxin, total bacteria, bacterial species, antimicrobial resistance genes and methanogenic archaea were examined. Methods. Bioaerosols were collected from fifteen CH and fifteen FH poultry operations using stationary area samplers as well as personal sampling devices. Dust was measured by gravimetric analyses. Limulus Amoebocyte Lysate (LAL) assays were used to quantify endotoxin. Bacteria and archaea concentrations were measured by quantitative PCR. Bacterial and archaeal diversity was investigated using PCR followed by denaturing gradient gel electrophoresis (DGGE) and sequencing. AMR genes were detected using end-point PCR. Results. Dust (p<0.001), endotoxin (p<0.05), total bacteria (p<0.05), Enterococcus (p<0.001), E. coli (p<0.001) and Staphylococcus (p<0.001) were more concentrated in bioaerosols from FH poultry operations than CH bioaerosols. Methanogenic archaea (p<0.001) and C. perfringens (p<0.05) were significantly higher in bioaerosols from CH facilities than FH bioaerosols. Zinc bacitracin resistance gene (bcrR), erythromycin resistance gene (ermA), and tetracycline resistance gene (tetA/C), were more prevalent in bioaerosols from FH facilities than CH bioaerosols (p<0.01, p<0.01 and p<0.05, respectively). Conclusions. Bioaerosols from CH and FH poultry operations are significantly different, suggesting that CH and FH workers are exposed to significantly different environments. Bacterial diversity, C. perfringens, archaea, and/or unmeasured components of bioaerosols may be contributing to the greater prevalence of respiratory symptoms observed in CH workers. Each barn type may require specific remediation methods. Future directions. In order to better understand the role of bioaerosols in poultry worker respiratory dysfunction, it will be necessary to examine airway inflammation following exposure to bioaerosols, or components of bioaerosols, from each poultry barn type

An aerobiological perspective of dust in cage-housed and floor-housed poultry operations

The Canadian poultry production industry contributes nearly $10 billion to the Canadian economy and employs nearly 50,000 workers. However, modern poultry facilities are highly contaminated with airborne dust. Although there are many bioaerosols in the poultry barn environment, endotoxin is typically attributed with the negative respiratory symptoms observed in workers. These adverse respiratory symptoms have a higher prevalence in poultry workers compared to workers from other animal confinement buildings. Workers in cage-housed operations compared to floor-housed facilities report a higher prevalence of some respiratory symptoms. We review the current state of knowledge on airborne dust in poultry barns and respiratory dysfunction in poultry workers while highlighting the areas that need further investigation. Our review focuses on the aerobiological pathway of poultry dust including the source and aerosolization of dust and worker exposure and response. Further understanding of the source and aerosolization of dust in poultry operations will aid in the development of management practices to reduce worker exposure and response

Nucleolytic processing of abasic sites underlies PARP inhibitor hypersensitivity in ALC1-deficient BRCA mutant cancer cells

Clinical success with poly (ADP-ribose) polymerase inhibitors (PARPi) is impeded by inevitable resistance and associated cytotoxicity. Depletion of Amplified in Liver Cancer 1 (ALC1), a chromatin-remodeling enzyme, can overcome these limitations by hypersensitizing BReast CAncer genes 1/2 (BRCA1/2) mutant cells to PARPi. Here, we demonstrate that PARPi hypersensitivity upon ALC1 loss is reliant on its role in promoting the repair of chromatin buried abasic sites. We show that ALC1 enhances the ability of the abasic site processing enzyme, Apurinic/Apyrimidinic endonuclease 1 (APE1) to cleave nucleosome-occluded abasic sites. However, unrepaired abasic sites in ALC1-deficient cells are readily accessed by APE1 at the nucleosome-free replication forks. APE1 cleavage leads to fork breakage and trapping of PARP1/2 upon PARPi treatment, resulting in hypersensitivity. Collectively, our studies reveal how cells overcome the chromatin barrier to repair abasic lesions and uncover cleavage of abasic sites as a mechanism to overcome limitations of PARPi

Epigenetic silencing of CREB3L1 by DNA methylation is associated with high-grade metastatic breast cancers with poor prognosis and is prevalent in triple negative breast cancers

Methylation within specific CpG regions of the CREB3L1 gene in different breast tumor subtypes. The relative methylation was plotted for each tumor subtype. Methylation in regions 2 and 3 show an inverse correlation with CREB3L1 mRNA expression (found in Fig. 6b), whereas methylation in regions 16, 19 and 20 show a direct correlation with CREB3L1 mRNA expression. For all panels: normal (n = 97), luminal (n = 357), human epidermal growth factor receptor 2 (HER2) amplified (n = 19), triple negative breast cancer (TNBC) (n = 113). Statistical differences were analyzed using post-hoc pairwise comparison: *p <0.05; **p <0.01; ***p <0.001. (PDF 97 kb

Mental Rotation Performance in Male Soccer Players

It is the main goal of this study to investigate the visual-spatial cognition in male soccer players. Forty males (20 soccer players and 20 non-athletes) solved a chronometric mental rotation task with both cubed and embodied figures (human figures, body postures). The results confirm previous results that all participants had a lower mental rotation speed for cube figures compared to embodied figures and a higher error rate for cube figures, but only at angular disparities greater than 90°. It is a new finding that soccer–players showed a faster reaction time for embodied stimuli. Because rotation speed did not differ between soccer-players and non-athletes this finding cannot be attributed to the mental rotation process itself but instead to differences in one of the following processes which are involved in a mental rotation task: the encoding process, the maintanence of readiness, or the motor process. The results are discussed against the background of the influence on longterm physical activity on mental rotation and the context of embodied cognition