The evolution and spread of antibiotic‐resistant bacteria have renewed interest in phage therapy, the use of bacterial viruses (phages) to combat bacterial infections. The delivery of phages in ...cocktails where constituent phages target different modalities (e.g., receptors) may improve treatment outcomes by making it more difficult for bacteria to evolve resistance. However, the multipartite nature of cocktails may lead to unintended evolutionary and ecological outcomes. Here, we compare a 2‐phage cocktail with a largely unconsidered group of phages: generalists that can infect through multiple, independent receptors. We find that λ phage generalists and cocktails that target the same receptors (LamB and OmpF) suppress Escherichia coli similarly for ~2 days. Yet, a “trained” generalist phage, which previously adapted to its host via 28 days of coevolution, demonstrated superior suppression. To understand why the trained generalist was more effective, we measured the resistance of bacteria against each of our phages. We find that, when bacteria were assailed by two phages in the cocktail, they evolved mutations in manXYZ, a host inner‐membrane transporter that λ uses to move its DNA across the periplasmic space and into the cell for infection. This provided cross‐resistance against the cocktail and untrained generalist. However, these mutations were ineffective at blocking the trained generalist because, through coevolutionary training, it evolved to bypass manXYZ resistance. The trained generalist's past experiences in training make it exceedingly difficult for bacteria to evolve resistance, further demonstrating the utility of coevolutionary phage training for improving the therapeutic properties of phages.
Floating treatment wetlands are innovative systems and their processes are still scarcely known within the traditional methods of phytodepuration. To gain initial information on their performance and ...potential in removing pollutants, two experiments have been conducted in northeast Italy, in a Natural Park with resurgent water. Barriers formed by a new patented floating element were tested in real climatic and water flow conditions. One experiment was conducted in a channel receiving aquaculture effluents, while the other was set in two cleaner channels to test two installation designs (two barriers composed of two lines of elements—2 × 2 design and two composed of three lines of elements—2 × 3 design). Different macrophyte species were used (
Phragmites australis, Carex elata, Juncus effusus, Typha latifolia, Chrysopogon zizanioides, Sparganium erectum,
and
Dactylis glomerata
). The floating systems were easily installed and required few maintenance operations. Native plants grew successfully, developing roots 90–135 cm deep 1 year after planting. Conversely,
Chrysopogon zizanioides
showed scarce adaptation to local conditions
.
In the first experiment, median chemical oxygen demand (COD) in water passing through the floating wetland system was reduced by 66%, biochemical oxygen demand by 52%, and total phosphorus by 65%. In the second experiment, the 2 × 3 design had a slightly better performance than 2 × 2 in reducing COD (38 and 28% of removal, respectively). The two designs performed similarly on NO
3
-N, reducing the incoming concentrations by 12% (2 × 3 design) and 14% (2 × 2). This form of nitrogen represents almost all the total nitrogen, which was abated by 13% by the 2 × 3 design and by 29% by 2 × 2 design.
The gastrointestinal microbiome plays a significant role in modulating numerous host processes, including metabolism. Prior studies show that when mice receive fecal transplants from obese donors on ...high-fat diets (HFD) (even when recipient mice are fed normal diets after transplantation), they develop obese phenotypes, demonstrating the prominent role that gut microbiota play in determining lean and obese phenotypes. While much of the credit has been given to gut bacteria, the impact of gut viruses on these phenotypes is understudied. To address this shortcoming, we gavaged mice with viromes isolated from donors fed HFD or normal chow over a 4-week study. By characterizing the gut bacterial biota via 16S rRNA amplicon sequencing and measuring mouse weights over time, we demonstrate that transplanted viruses affect the gut bacterial community, as well as weight gain/loss. Notably, mice fed chow but gavaged with HFD-derived viromes gained more weight than their counterparts receiving chow-derived viromes. The converse was also true: mice fed HFD but gavaged with chow-derived viromes gained less weight than their counterparts receiving HFD-derived viromes. Results were replicated in two independent experiments and phenotypic changes were accompanied by significant and identifiable differences in the fecal bacterial biota. Due to methodological limitations, we were unable to identify the specific bacterial strains responsible for respective phenotypic changes. This study confirms that virome-mediated perturbations can alter the fecal microbiome in vivo and indicates that such perturbations are sufficient to drive lean and obese phenotypes in mice.
Idiopathic sudden sensorineural hearing loss (ISSNHL) represents an acute inner ear disorder with an overall incidence of 5-20/100000 individuals per year in western countries. No clear causes for ...this disease have been found so far, but cochlear ischemia has been hypothesized as one of the etiopathological mechanisms. The aim of our study was to assess the role of diabetes and traditional cardiovascular risk factors in the pathogenesis of ISSNHL.
Case-control study of 141 patients (75 males/66 females) matched for age and gender. Cases were affected by ISSNHL, defined as a sudden hearing loss > or =30 dB, within 3 frequencies, developing over 72 h. The control group was composed of 271 sex- and age-matched subjects (142 males/129 females) who agreed to participate in this observational study and provided blood samples for laboratory investigations. Cardiovascular risk factors examined were: diabetes mellitus, smoking history, hypercholesterolemia, hypertriglyceridemia and hypertension.
On the univariate analysis, diabetes prevalence was higher in the ISSNHL group (15.6%) compared to controls (8.5%) (p = 0.03). Also hypercholesterolemia was significantly more frequent in the ISSNHL group compared to the control population. There were no statistically significant differences between the 2 populations concerning other cardiovascular risk factors. The risk of ISSNHL tended to increase as the number of cardiovascular risk factors increased (p for linear trend = 0.018).
Our findings suggest that diabetes mellitus, hypercholesterolemia and a high burden of cardiovascular risk factors are associated with the risk of ISSNHL.
•A. donax gave the highest ethanol (3.9 Mg ha−1) and methane (9056 m3 ha−1) yields.•M. giganteus produced 3.1 Mg ha−1 of ethanol and 4325 m3 ha−1 of methane.•Methane transformation showed higher ...energy output than ethanol.•A. donax and M. x giganteus were the most interesting bioenergy species.
The research aimed to study and characterize, in a four-year study, thirteen pluri-annual herbaceous species for their potential bioethanol and biomethane production. The highest biomass yield was obtained with Arundo donax followed by Miscanthus x giganteus. Biomass cellulose content had median values ranging from 23.1% (Symphytum x uplandicum) to 45.4% (Lythrum salicaria), hemicellulose from 9.4% (Iris pseudacorus) to 36.8% (Glyceria maxima) and lignin from 2.6% (G. maxima) to 14.5% (Helianthus tuberosus and L. salicaria). The best ethanol and methane median yields were achieved by A. donax (3.5 Mg ha−1 and 8227 m3 ha−1, respectively) followed by M. x giganteus (3.2 Mg ha−1 and 4446 m3 ha−1, respectively). Methane transformation showed a higher energy output than ethanol with values ranging from 1 GJ ha−1 (Phalaris arundinacea) to 508 GJ ha−1 (A. donax) and from 1 GJ ha−1 (P. arundinacea) to 624 GJ ha−1 (A. donax) for ethanol and methane, respectively. Results showed that A. donax and M. x giganteus are the most interesting species for bioethanol and biomethane production.
The evolution of antibiotic-resistant bacteria threatens to become the leading cause of worldwide mortality. This crisis has renewed interest in the practice of phage therapy. Yet, bacteria's ...capacity to evolve resistance may debilitate this therapy as well. To combat the evolution of phage resistance and improve treatment outcomes, many suggest leveraging phages' ability to counter resistance by evolving phages on target hosts before using them in therapy (phage training). We found that in vitro, λtrn, a phage trained for 28 d, suppressed bacteria ∼1,000-fold for three to eight times longer than its untrained ancestor. Prolonged suppression was due to a delay in the evolution of resistance caused by several factors. Mutations that confer resistance to λtrn are ∼100× less common, and while the target bacterium can evolve complete resistance to the untrained phage in a single step, multiple mutations are required to evolve complete resistance to λtrn. Mutations that confer resistance to λtrn are more costly than mutations for untrained phage resistance. Furthermore, when resistance does evolve, λtrn is better able to suppress these forms of resistance. One way that λtrn improved was through recombination with a gene in a defunct prophage in the host genome, which doubled phage fitness. This transfer of information from the host genome is an unexpected but highly efficient mode of training phage. Lastly, we found that many other independently trained λ phages were able to suppress bacterial populations, supporting the important role training could play during phage therapeutic development.
Alterations in diet can have significant impact on the host, with high-fat diet (HFD) leading to obesity, diabetes, and inflammation of the gut. Although membership and abundances in gut bacterial ...communities are strongly influenced by diet, substantially less is known about how viral communities respond to dietary changes. Examining fecal contents of mice as the mice were transitioned from normal chow to HFD, we found significant changes in the relative abundances and the diversity in the gut of bacteria and their viruses. Alpha diversity of the bacterial community was significantly diminished in response to the diet change but did not change significantly in the viral community. However, the diet shift significantly impacted the beta diversity in both the bacterial and viral communities. There was a significant shift away from the relatively abundant
accompanied by increases in bacteriophages from the
family. The proportion of identified bacteriophage structural genes significantly decreased after the transition to HFD, with a conserved loss of integrase genes in all four experimental groups. In total, this study provides evidence for substantial changes in the intestinal virome disproportionate to bacterial changes, and with alterations in putative viral lifestyles related to chromosomal integration as a result of shift to HFD.
Prior studies have shown that high-fat diet (HFD) can have profound effects on the gastrointestinal (GI) tract microbiome and also demonstrate that bacteria in the GI tract can affect metabolism and lean/obese phenotypes. We investigated whether the composition of viral communities that also inhabit the GI tract are affected by shifts from normal to HFD. We found significant and reproducible shifts in the content of GI tract viromes after the transition to HFD. The differences observed in virome community membership and their associated gene content suggest that these altered viral communities are populated by viruses that are more virulent toward their host bacteria. Because HFD also are associated with significant shifts in GI tract bacterial communities, we believe that the shifts in the viral community may serve to drive the changes that occur in associated bacterial communities.
Ecosystem services provided by wetland systems presently play a pivotal role in intensive cropland as water purification from agricultural pollution. A field trial was conducted in 2014 to evaluate ...herbicide runoff reduction and retention using a 0.32 ha constructed surface flow wetland (CSFW) at the outlet of a 6 ha agricultural basin. To simulate an extreme pulse contamination, the CSFW was flooded with a runoff contaminated with metolachlor, and terbuthylazine and two other subsequent floods with pure water were applied 21 and 65 days later. Results show that the CSFW can reduce runoff concentration of metolachlor and terbuthylazine by a factor of 45–80 even in extreme flooding conditions. Herbicides retention in the CSFW was reversible, and the second and third floods mobilized 14–31 and 3.5–7.0% respectively, of the amount detected in the first flood. The CSFW performs a high buffer capacity for herbicides, capable to provide water purification service, protecting downstream surface water. Moreover, mitigation capacity of a CSFW for a heavy runoff from a 10 ha basin is 90% for every 50 m in length of a 15 m wide wetland. This confirms that the implementation of CSFWs in agro-systems can improve the sustainability of agricultural production.
The development of biocompatible polymeric nanoparticles has become an important strategy for optimizing the therapeutic efficacy of many classical drugs, as it may expand their activities, reduce ...their toxicity, increase their bioactivity and improve biodistribution. In this study, nanoparticles of Amphotericin B entrapped within poly (lactic-co-glycolic) acid and incorporated with dimercaptosuccinic acid (NANO-D-AMB) as a target molecule were evaluated for their physic-chemical characteristics, pharmacokinetics, biocompatibility and antifungal activity. We found high plasma concentrations of Amphotericin B upon treatment with NANO-D-AMB and a high uptake of nanoparticles in the lungs, liver and spleen. NANO-D-AMB exhibited antifungal efficacy against Paracoccidioides brasiliensis and induced much lower cytotoxicity levels compared to D-AMB formulation in vivo and in vitro. Together, these results confirm that NANO-D-AMB improves Amphotericin B delivery and suggest this delivery system as a potential alternative to the use of Amphotericin B sodium deoxycholate.
Biodistribution scintigraphic images of nanoparticles labeled with the radioisotope technetium 99: amphotericin loaded nanoparticles (99mTc-NANO-D-AMB) or free DMSA after 1 and 8 h of intravenously injection. Display omitted
•Amphotericin B is a widely used antifungal, but toxicity limits its use.•NANO-D-AMB was proposed to optimize efficacy and reduce toxicity of this drug.•NANO-D-AMB had similar antifungal efficacy than AMBISOME®.•NANO-D-AMB had lower toxicity compared to D-AMB in vivo and in vitro.•NANO-D-AMB improves drug delivery and might be a potential alternative to D-AMB.
To evaluate the soybean polyphenol glucosides bioconversion to aglycone forms by different β-glucosidases-producing filamentous fungi to enhance their antioxidant activity. Soybean defatted flour was ...submitted to solid-state fermentation with Aspergillus niger, Aspergillus niveus and Aspergillus awamori. The fungi studied produced approximately the same β-glucosidase activity units amount when p-nitrophenyl-β- d-glucopyranoside was used as substrate for the assay. However, electrophoretic analysis, using 4-methylumbellipheryl-β- d-glucopyranoside as substrate, showed that β-glucosidase produced by A. niveus was more active. Fermented methanolic extracts showed an increase in polyphenol and genistein contents and antioxidant activities. The highest genistein content was found in soybean fermented by A. niveus. Methanolic extracts of the soybean fermented by the different fungi showed a similar capacity of scavenging H₂O₂ generated in vivo by the tumour promoter 12-O-tetradecanoyl phorbol-13-acetate. A. niveus synthesized a β-glucosidase with higher specificity to hydrolyse genistin β-glycosidic bond than those produced by A. awamori and A. niger. The utilization of these β-glucosidases-producing fungi in soybean fermentation processes resulted in the obtaining of methanolic extracts with different antioxidant potentials that could be used either therapeutically or as an antioxidant in nonphysiological oxidative stress conditions, as the one induced in skin by UV radiation.
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