Asie : Népal : Région de développement Ouest : Zone de Gandaki : Vallée de la Soti khola : Vendeur de lait en bordure de chemin, à Shyamran

Légende manuscrite sur le document original : ''Vallée de la Buri Gandaki. Zone supérieure des moyens pays. Vendeur de lait en bordure du chemin. '' Géolocalisation : approximative centrée sur Shyamran

Effect of relative humidity and exposure time on four aerosolized phage models.

<p>Experiments were conducted at 19°C with 25% (black circles) and 50% (black squares) relative humidity. a, b, c indicate significant effect of exposure time for phages ϕX174 and PR772. The asterisk (*) indicates a significant difference between 25% and 50% relative humidity for phages ϕ6 and PR772.</p

Primers and probes used in this study.

<p>Primers and probes used in this study.</p

Endotoxins in Indoor Air and Settled Dust in Primary Schools in a Subtropical Climate

Endotoxins can significantly affect the air quality in school environments. However, there is currently no reliable method for the measurement of endotoxins, and there is a lack of reference values for endotoxin concentrations to aid in the interpretation of measurement results in school settings. We benchmarked the “baseline” range of endotoxin concentration in indoor air, together with endotoxin load in floor dust, and evaluated the correlation between endotoxin levels in indoor air and settled dust, as well as the effects of temperature and humidity on these levels in subtropical school settings. Bayesian hierarchical modeling indicated that the concentration in indoor air and the load in floor dust were generally (<95th percentile) <13 EU/m³ and <24,570 EU/m², respectively. Exceeding these levels would indicate abnormal sources of endotoxins in the school environment and the need for further investigation. Metaregression indicated no relationship between endotoxin concentration and load, which points to the necessity for measuring endotoxin levels in both the air and settled dust. Temperature increases were associated with lower concentrations in indoor air and higher loads in floor dust. Higher levels of humidity may be associated with lower airborne endotoxin concentrations

Behavior of the four phages under tested conditions.

<p>Behavior of the four phages under tested conditions.</p

Bacteria and phages used in this study.

<p>Bacteria and phages used in this study.</p

Increased Prevalence of <i>Methanosphaera stadtmanae</i> in Inflammatory Bowel Diseases

<div><p>Background</p><p>The gut microbiota is associated with the modulation of mucosal immunity and the etiology of inflammatory bowel diseases (IBD). Previous studies focused on the impact of bacterial species on IBD but seldom suspected archaea, which can be a major constituent of intestinal microbiota, to be implicated in the diseases. Recent evidence supports that two main archaeal species found in the digestive system of humans, <i>Methanobrevibacter smithii</i> (MBS) and <i>Methanosphaera stadtmanae</i> (MSS) can have differential immunogenic properties in lungs of mice; with MSS but not MBS being a strong inducer of the inflammatory response. We thus aimed at documenting the immunogenic potential of MBS and MSS in humans and to explore their association with IBD.</p><p>Methods</p><p>To validate the immunogenicity of MBS and MSS in humans, peripheral blood mononuclear cells from healthy subjects were stimulated with these two microorganisms and the production of inflammatory cytokine TNF was measured by ELISA. To verify MBS and MSS prevalence in IBD, stool samples from 29 healthy control subjects and 29 patients suffering from IBD were collected for DNA extraction. Plasma was also collected from these subjects to measure antigen-specific IgGs by ELISA. Quantitative PCR was used for bacteria, methanogens, MBS and MSS quantification.</p><p>Results</p><p>Mononuclear cells stimulated with MSS produced higher concentrations of TNF (39.5 ng/ml) compared to MBS stimulation (9.1 ng/ml). Bacterial concentrations and frequency of MBS-containing stools were similar in both groups. However, the number of stool samples positive for the inflammatory archaea MSS was higher in patients than in controls (47% vs 20%). Importantly, only IBD patients developed a significant anti-MSS IgG response.</p><p>Conclusion</p><p>The prevalence of MSS is increased in IBD patients and is associated with an antigen-specific IgG response.</p></div

IgG response in plasma of controls subjects and IBD patients.

<p>Titers of A) MBS- and B) MSS-specific IgGs. C) Quantification of total IgGs. Results are expressed as average ± SEM. Eighteen controls (9 positive for MBS and 4 positive for MSS in stool samples) and seventeen patients (6 positive for MBS and 9 positive for MSS in stool samples) were analyzed. p<0.05.</p

Primers and probes used in the study.

<p>Primers and probes used in the study.</p

Dominance of CD4⁺ T lymphocytes and CD19⁺ B lymphocytes in BALF of mice instilled with archaeal species.

<p>The numbers of CD4⁺ T cells, CD8⁺ T cells and CD19⁺ B cells were analyzed in BALF of mice exposed for 3 weeks to 6.25, 25 and 100 µg of A) MBS or B) MSS. Compared to MBS, MSS induced strong CD4⁺ helper T cell and CD19⁺ B cell responses in the airways, which plateaued from the lowest dose instilled. Results are expressed as median ± interquartile intervals. Letters a and b represent statistical differences between treatment regimens within a same cell type. Six mice per group were analyzed. p<0.05.</p