| 1. |
- Abrego, Nerea, et al.
(författare)
-
Airborne DNA reveals predictable spatial and seasonal dynamics of fungi
- 2024
-
Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 631, s. 835-842
-
Tidskriftsartikel (refereegranskat)abstract
- Fungi are among the most diverse and ecologically important kingdoms in life. However, the distributional ranges of fungi remain largely unknown as do the ecological mechanisms that shape their distributions1,2. To provide an integrated view of the spatial and seasonal dynamics of fungi, we implemented a globally distributed standardized aerial sampling of fungal spores3. The vast majority of operational taxonomic units were detected within only one climatic zone, and the spatiotemporal patterns of species richness and community composition were mostly explained by annual mean air temperature. Tropical regions hosted the highest fungal diversity except for lichenized, ericoid mycorrhizal and ectomycorrhizal fungi, which reached their peak diversity in temperate regions. The sensitivity in climatic responses was associated with phylogenetic relatedness, suggesting that large-scale distributions of some fungal groups are partially constrained by their ancestral niche. There was a strong phylogenetic signal in seasonal sensitivity, suggesting that some groups of fungi have retained their ancestral trait of sporulating for only a short period. Overall, our results show that the hyperdiverse kingdom of fungi follows globally highly predictable spatial and temporal dynamics, with seasonality in both species richness and community composition increasing with latitude. Our study reports patterns resembling those described for other major groups of organisms, thus making a major contribution to the long-standing debate on whether organisms with a microbial lifestyle follow the global biodiversity paradigms known for macroorganisms4,5.
|
|
| 2. |
- Hammarström, Helena, et al.
(författare)
-
Treatment with reduced dose trimethoprim-sulfamethoxazole is effective in mild to moderate Pneumocystis jirovecii pneumonia in patients with hematologic malignancies
- 2023
-
Ingår i: Clinical Infectious Diseases. - : University of Chicago Press. - 1058-4838 .- 1537-6591. ; 76:3, s. e1252-e1260
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent studies have reported that reduced dose trimethoprim-sulfamethoxazole (TMP-SMX) may be effective in the treatment of Pneumocystis jirovecii pneumonia (PJP) but data is lacking for patients with hematologic malignancies.METHODS: This retrospective study included all adult hematologic patients with PJP between 2013 and 2017 at six Swedish University Hospitals. Treatment with 7.5-15 mg TMP/kg/day (reduced dose) was compared with >15-20 mg TMP/kg/day (standard dose), after correction for renal function. The primary outcome was the change in respiratory function (ΔPaO2/FiO2) between baseline and day 8. Secondary outcomes were clinical failure and/or death at day 8 and death at day 30.RESULTS: Out of a total of 113 included patients, 80 patients received reduced dose, and 33 patients received standard dose. The overall 30-day mortality in the whole cohort was 14%. There were no clinically relevant differences in ΔPaO2/FiO2 at day 8 between the treatment groups, neither before nor after controlling for potential confounders in an adjusted regression model (-13,6 mmHg [95% CI -56,7-29,5] and -9,4 mmHg, [95% CI -50.5-31.7], respectively). Clinical failure and/or death at day 8 and 30-day mortality did not differ significantly between the groups, 18% vs. 21% and 14% vs. 15%, respectively. Among patients with mild to moderate pneumonia, defined as PaO2/FiO2>200 mmHg, all 44 patients receiving reduced dose were alive at day 30.CONCLUSION: In this cohort of 113 patients with hematologic malignancies, reduced dose TMP-SMX was effective and safe for treating mild to moderate PJP.
|
|
| 3. |
- Kmezik, Cathleen, 1991, et al.
(författare)
-
A polysaccharide utilization locus from the gut bacterium Dysgonomonas mossii encodes functionally distinct carbohydrate esterases.
- 2021
-
Ingår i: The Journal of biological chemistry. - : Elsevier BV. - 1083-351X .- 0021-9258. ; 296
-
Tidskriftsartikel (refereegranskat)abstract
- The gut microbiota plays a central role in human health by enzymatically degrading dietary fiber and concomitantly excreting short chain fatty acids that are associated with manifold health benefits. The polysaccharide xylan is abundant in dietary fiber but non-carbohydrate decorations hinder efficient cleavage by glycoside hydrolases (GHs) and need to be addressed by carbohydrate esterases (CEs). Enzymes from carbohydrate esterase families 1 and 6 (CE1 & 6) perform key roles in xylan degradation by removing feruloyl and acetate decorations, yet little is known about these enzyme families especially with regards to their diversity in activity. Bacteroidetes bacteria are dominant members of the microbiota and often encode their carbohydrate-active enzymes in multi-gene polysaccharide utilization loci (PULs). Here we present the characterization of three CEs found in a PUL encoded by the gut Bacteroidete Dysgonomonas mossii. We demonstrate that the CEs are functionally distinct, with one highly efficient CE6 acetyl esterase and two CE1 enzymes with feruloyl esterase activities. One multidomain CE1 enzyme contains two CE1 domains: an N-terminal domain feruloyl esterase, and a C-terminal domain with minimal activity on model substrates. We present the structure of the C-terminal CE1 domain with the carbohydrate binding module that bridges the two CE1 domains, as well as a complex of the same protein fragment with methyl ferulate. The investment of D. mossii in producing multiple CEs suggests that improved accessibility of xylan for GHs as well as cleavage of covalent polysaccharide-polysaccharide and lignin-polysaccharide bonds are important enzyme activities in the gut environment.
|
|
| 4. |
- Ovaskainen, Otso, et al.
(författare)
-
Global Spore Sampling Project: A global, standardized dataset of airborne fungal DNA
- 2024
-
Ingår i: Scientific Data. - 2052-4463. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Novel methods for sampling and characterizing biodiversity hold great promise for re-evaluating patterns of life across the planet. The sampling of airborne spores with a cyclone sampler, and the sequencing of their DNA, have been suggested as an efficient and well-calibrated tool for surveying fungal diversity across various environments. Here we present data originating from the Global Spore Sampling Project, comprising 2,768 samples collected during two years at 47 outdoor locations across the world. Each sample represents fungal DNA extracted from 24 m3 of air. We applied a conservative bioinformatics pipeline that filtered out sequences that did not show strong evidence of representing a fungal species. The pipeline yielded 27,954 species-level operational taxonomic units (OTUs). Each OTU is accompanied by a probabilistic taxonomic classification, validated through comparison with expert evaluations. To examine the potential of the data for ecological analyses, we partitioned the variation in species distributions into spatial and seasonal components, showing a strong effect of the annual mean temperature on community composition.
|
|
| 5. |
|
|
