Chitosan based ethanolicAllium Sativumextract hydrogel film: a novel skin tissue regeneration platform for 2nd degree burn wound healing.

This study investigated the potential of ethanolic garlic extract-loaded chitosan hydrogel film for burn wound healing in an animal model. The ethanolic garlic extract was prepared by macerating fresh ground garlic cloves in ethanol for 24 h, followed by filtration and concentration using a rotary evaporator. Hydrogels were then prepared by casting a chitosan solution with garlic extract added at varying concentrations for optimization and, following drying, subjected to various characterization tests, including moisture adsorption (MA), water vapor transmission rate (WVTR), and water vapor permeability rate (WVPR), erosion, swelling, tensile strength, vibrational, and thermal analysis, and surface morphology. The optimized hydrogel (G2) was then analyzedin vivofor its potential for healing 2nd degree burn wounds in rats, and histological examination of skin samples on day 14 of the healing period. Results showed optimized hydrogel (G2; chitosan: 2 g, garlic extract: 1 g) had MA of 56.8% ± 2.7%, WVTR and WVPR of 0.00074 ± 0.0002, and 0.000 498 946 ± 0.0001, eroded up to 11.3% ± 0.05%, 80.7% ± 0.04% of swelling index, and tensile strength of 16.6 ± 0.9 MPa, which could be attributed to the formation of additional linkages between formulation ingredients and garlic extract constituents at OH/NH and C=O, translating into an increase in transition melting temperature and enthalpy (ΔT= 238.83 °C ± 1.2 °C, ΔH= 4.95 ± 0.8 J g-1) of the chitosan moieties compared with blank. Animal testing revealed G2 formulation significantly reduced the wound size within 14 d of the experiment (37.3 ± 6.8-187.5 ± 21.5 mm2) and had significantly higher reepithelization (86.3 ± 6.8-26.8 ± 21.5 and 38.2% ± 15.3%) compared to untreated and blank groups by hastening uniform and compact deposition of collagen fibers at the wound site, cementing developed formulation a promising platform for skin regeneration.

Sex- and age-dependent associations of EPA and DHA with very short sleep duration in adults: a cross-sectional analysis.

OBJECTIVES: This study aimed to compare the efficacy of dietary intake of eicosapentaenoic acid (EPA; 20:5 ω-3) and docosahexaenoic acid (DHA; 22:6 ω-3) on very short sleep duration (<5 h/night) in adults. METHODS: The bootstrap method was used in the multinomial logistic regression to estimate the ORs and corresponding 95% confidence intervals (CIs) of very short sleep duration. We used rolling window method to analyze the effects of EPA and DHA dietary intakes on very short sleep durations in men and women over age. To illustrate the stability of the results for the selected window width, we built a shiny application. RESULTS: Compared to the first quartile, the mean ORs of EPA intake on very short sleep duration and the corresponding 95% CIs for the second, third and fourth quartiles of EPA intake among men under 32 years old were 1.50 (0.56, 3.44) mg, 1.55 (0.59, 3.48) mg, and 3.99 (1.15, 10.01) mg, respectively. Among women over 44 years old, the ORs for DHA intake were 1.12 (0.81, 1.52) mg, 0.94 (0.68, 1.29) mg, and 0.62 (0.38, 0.98) mg for the second, third and fourth quartiles, respectively. CONCLUSIONS: The associations of EPA and DHA with very short sleep duration are sex- and age-dependent. In males under the age of 32, a significant positive correlation exists between dietary EPA intake and very short sleep duration. For women above 44 years of age, an increase in DHA intake can notably ameliorate issues of very short sleep duration.

Assessing in-hospital mortality and predictors in Patients with contrast-induced nephropathy Following primary percutaneous coronary Intervention.

BACKGROUND: The contrast-induced nephropathy (CIN) is a common complication of primary percutaneous coronary intervention (PCI) it has been reported to be associated with an increased risk of mortality. The study reported the in-hospital mortality among patients who developed CIN after primary PCI. METHODS: This descriptive cross-sectional study was conducted on a sample of consecutive who developed CIN after primary PCI at a tertiary care cardiac hospital in Karachi, Pakistan. The CIN was defined as either a relative increase of 25% or an absolute increase of 0.5 mg/dL in post -procedure serum creatinine within 72 hours. The in-hospital mortality status was recorded and clinical and demographic predictors of in-hospital mortality were identified with the help of binary logistic regression analysis. RESULTS: In the study sample of 402 patients, 74.1% (298) were male and the mean age of the study sample was 59.4±11.5 years. The in-hospital mortality rate was 9.7% (39). On multivar iable analysis, an increased risk of mortality was found to be independently associated with inferior wall myocardial infarction (IWMI) with right ventricular (RV) infarction, intra-procedure arrhythmias, and pump failure with an adjusted odds ratio of 3.63 [95% CI: 1.31-10.08; p=0.013], 5.53 [95% CI: 1.39-22.06; p=0.015], and 8.94 [95% CI: 3.99-20.02; p<0.001], respectively. CONCLUSIONS: In conclusion, there is a high rate of mortality for patients who develop CIN after primary PCI, and the risk of mortality is further aggravated by the presence of IWMI with RV infarction, intra-procedure arrhythmias, and pump failure.

The exceptionally efficient quorum quenching enzyme LrsL suppresses Pseudomonas aeruginosa biofilm production.

Quorum quenching (QQ) is the enzymatic degradation of molecules used by bacteria for synchronizing their behavior within communities. QQ has attracted wide attention due to its potential to inhibit biofilm formation and suppress the production of virulence factors. Through its capacity to limit biofouling and infections, QQ has applications in water treatment, aquaculture, and healthcare. Several different QQ enzymes have been described; however, they often lack the high stability and catalytic efficiency required for industrial applications. Previously, we identified genes from genome sequences of Red Sea sediment bacteria encoding potential QQ enzymes. In this study, we report that one of them, named LrsL, is a metallo-ß-lactamase superfamily QQ enzyme with outstanding catalytic features. X-ray crystallography shows that LrsL is a zinc-binding dimer. LrsL has an unusually hydrophobic substrate binding pocket that can accommodate a broad range of acyl-homoserine lactones (AHLs) with exceptionally high affinity. In vitro, LrsL achieves the highest catalytic efficiency reported thus far for any QQ enzyme with a Kcat /KM of 3 × 107. LrsL effectively inhibited Pseudomonas aeruginosa biofilm formation without affecting bacterial growth. Furthermore, LrsL suppressed the production of exopolysaccharides required for biofilm production. These features, and its capacity to regain its function after prolonged heat denaturation, identify LrsL as a robust and unusually efficient QQ enzyme for clinical and industrial applications.

Physicochemical Properties of Extracellular Polymeric Substances Produced by Three Bacterial Isolates From Biofouled Reverse Osmosis Membranes.

This work describes the chemical composition of extracellular polymeric substances (EPS) produced by three bacteria (RO1, RO2, and RO3) isolated from a biofouled reverse osmosis (RO) membrane. We isolated pure cultures of three bacterial strains from a 7-year-old biofouled RO module that was used in a full-scale seawater treatment plant. All the bacterial strains showed similar growth rates, biofilm formation, and produced similar quantities of proteins and polysaccharides. The gel permeation chromatography showed that the EPS produced by all the strains has a high molecular weight; however, the EPS produced by strains RO1 and RO3 showed the highest molecular weight. Fourier Transform Infrared Spectroscopy (FTIR), Proton Nuclear Magnetic Resonance (1H NMR), and Carbon NMR (13C NMR) were used for a detailed characterization of the EPS. These physicochemical analyses allowed us to identify features of EPS that are important for biofilm formation. FTIR analysis indicated the presence of α-1,4 glycosidic linkages (920 cm-1) and amide II (1,550 cm-1) in the EPS, the presence of which has been correlated with the fouling potential of bacteria. The presence of α-glycoside linkages was further confirmed by 13C NMR analysis. The 13C NMR analysis also showed that the EPS produced by these bacteria is chemically similar to foulants obtained from biofouled RO membranes in previous studies. Therefore, our results support the hypothesis that the majority of substances that cause fouling on RO membranes originate from bacteria. Investigation using 1H NMR showed that the EPS contained a high abundance of hydrophobic compounds, and these compounds can lead to flux decline in the membrane processes. Genome sequencing of the isolates showed that they represent novel species of bacteria belonging to the genus Bacillus. Examination of genomes showed that these bacteria carry carbohydrates-active enzymes that play a role in the production of polysaccharides. Further genomic studies allowed us to identify proteins involved in the biosynthesis of EPS and flagella involved in biofilm formation. These analyses provide a glimpse into the physicochemical properties of EPS found on the RO membrane. This knowledge can be useful in the rational design of biofilm control treatments for the RO membrane.

Removal of Bacteria and Organic Carbon by an Integrated Ultrafiltration-Nanofiltration Desalination Pilot Plant.

Fouling caused by organic matter and bacteria remains a significant challenge for the membrane-based desalination industry. Fouling decreases the permeate quality and membrane performance and also increases energy demands. Here, we quantified the amount of organic matter and bacteria at several stages along the water-treatment train of an integrated ultrafiltration-nanofiltration seawater treatment pilot plant. We quantified the organic matter, in terms of Total Organic Carbon (TOC) and Assimilable Organic Carbon (AOC), and evaluated its composition using Liquid Chromatography for Organic Carbon Detection (LC-OCD). The bacterial cells were counted using Bactiquant. We found that ultrafiltration (UF) was effective at removing bacterial cells (99.7%) but not TOC. By contrast, nanofiltration (NF) successfully removed both TOC (95%) and bacterial cells. However, the NF permeate showed higher amounts of AOC than seawater. LC-OCD analysis suggested that the AOC was mostly composed of low molecular weight neutral substances. Furthermore, we found that the cleaning of the UF membrane using chemically enhanced backwash reduced the amount of AOC released into the UF permeate. By implementing the cleaning-in-place of the NF membrane, the pressure drop was restored to the normal level. Our results show that the UF and NF membrane cleaning regimes investigated in this study improved membrane performance. However, AOC remained the hardest-to-treat fraction of organic carbon. AOC should, therefore, be monitored closely and regularly to mitigate biofouling in downstream processes.

Draft Genome Sequences of Three Bacillus Species Isolated from Biofouled Reverse-Osmosis Membranes.

Here, we present the draft genome sequences of three bacteria belonging to the genus Bacillus which were isolated from biofouled reverse-osmosis (RO) membranes harvested from a full-scale desalination plant. The sizes of the assembled genomes for RO1, RO2, and RO3 were 4.22 Mb, 4.15 Mb, and 4.23 Mb, respectively.

Evaluating the effect of hydraulic retention time on fouling development and biomass characteristics in an algal membrane photobioreactor treating a secondary wastewater effluent.

Coupling algal biomass growth to wastewater treatment is a promising alternative for the simultaneous removal and recovery of nutrients. This study aims to evaluate the effects of the Hydraulic Retention Time (HRT) on the fouling behavior and biomass characteristics of C. Vulgaris in a Membrane Photobioreactor (MPBR), fed with a secondary synthetic wastewater effluent. The changes in the algal cell characteristics and in their metabolic products were assessed at three different HRTs (12 h, 24 h and 36 h). Experimental results showed that higher loading rates led to a broader Particle Size Distribution (PSD) resulting from looser and less stable algal flocs. In contrast, bigger and homogeneously distributed particles observed at lower loading rates, led to a porous layer with lower fouling rates and organic removal. The presence of smaller particles and dissolved organics resulted in a more compact and less porous layer that increased the removal of small-MW organics.

Metagenomic analysis of sludge and early-stage biofilm communities of a submerged membrane bioreactor.

Biofilm formation on membranes in activated sludge membrane bioreactors (MBR), commonly identified as biofouling, is a significant problem for MBR operations. A better understanding of microbial species involved in the biofilm formation is needed to develop anti-biofilm measures. A read-based and genome-resolved shotgun metagenomic approach was applied to characterize the composition and functional potential of the sludge and early stage biofilm microbial communities in an MBR process. Read-based analysis revealed that the prevalence of different phyla are relatively similar in both the sludge and biofilm samples, with Proteobacteria as the most dominant, followed by Chloroflexi, Bacteroidetes and Planctomycetes. However, the relative abundance of these phyla slightly varies between the sludge and biofilm. Phyla such as Actinobacteria, bacterial candidate phyla, Chlamydiae, Cyanobacteria/Melainabacteria and Firmicutes are 2 to 4 times more abundant in the biofilm than in the sludge. At the genus level, genera belonging to Proteobacteria (Legionella, Caulobacter, Sphingomonas, Acinetobacter and Rhizobium), Cyanobacteria (Hassallia), and Spirochaetes (Turneriella) are at least twice more abundant in the biofilm. These genera, especially those belonging to Phylum Proteobacteria, are known to play an important role in the formation of biofilms on surfaces. The Alpha diversity is found slightly higher in the biofilm, compared with sludge samples. Functional classification of reads through the SEED subsystem shows that functional classes such as those involved in the metabolism of various molecules are significantly different in the biofilm and sludge. A phylogenomic analysis of the six extracted metagenome assembled genomes (MAGs) shows that three MAGs belong to Proteobacteria, and one MAG belong to each of Chloroflexi, Bacteroidetes and Planctomycetes. The relative abundance of the MAG belonging to Alphaproteobacteria is higher in the biofilm. A functional potential analysis of the MAGs reveals their potential to metabolize carbon and nitrogen sources, as well as the prevalence of antibiotic resistance genes.

Genome-resolved metagenomic analysis reveals roles of microbial community members in full-scale seawater reverse osmosis plant.

Biofouling of Reverse Osmosis (RO) membrane is a significant issue for the water treatment industry. In this study, we apply the metagenomic shot-gun sequencing technology to characterise the composition and functional potential of the microbial community in a full-scale RO plant, at different stages of seawater treatment. We find Proteobacteria, Bacteroidetes and Planctomycetes to be the most abundant bacterial phyla. The genetic potential of the RO membrane microbial community shows the enrichment of genes involved in biofilm formation, representing the selective pressure of the biofilm formation process. We recover 31 metagenome-assembled genomes (MAGs) from intake (raw seawater), fouled RO membranes (leading and middle RO module) and brine reject water. A total of 25 MAGs are recovered from the biofilm samples (leading and middle RO modules), with 9 of them (36%) belonging to Planctomycetes. We investigate all 25 MAGs for genes (pili, flagella, quorum sensing, quorum quenching and nitrate reduction) that play an important role in biofilm formation and sustenance of cells. We show that Planctomycetes contain genes for the formation of flagella and pili, and the reduction of nitrate. Although genes for quorum sensing are not detected, quorum quenching genes are identified in the biofilm MAGs. Our results show that Planctomycetes, along with other microbes, play an important role in the formation and sustenance of biofilms on seawater RO membranes.

Genome sequence analysis of Zooshikella ganghwensis strain VG4 and its potential for the synthesis of antimicrobial metabolites.

With antimicrobial resistance on the rise, the discovery of new compounds with novel structural scaffolds exhibiting antimicrobial properties has become an important area of research. Such compounds can serve as starting points for the development of new antimicrobials. In this report, we present the draft genome sequence of the Zooshikella ganghwensis strain VG4, isolated from Red Sea sediments, that produces metabolites with antimicrobial properties. A genomic analysis reveals that it carries at least five gene clusters that have the potential to direct biosynthesis of bioactive secondary metabolites such as polyketides and nonribosomal peptides. By using in-silico approaches, we predict the structure of these metabolites.

Quorum-Quenching Bacteria Isolated From Red Sea Sediments Reduce Biofilm Formation by Pseudomonas aeruginosa.

Quorum sensing (QS) is the process by which bacteria communicate with each other through small signaling molecules such as N-acylhomoserine lactones (AHLs). Certain bacteria can degrade AHL molecules by a process called quorum quenching (QQ); therefore, QQ can be used to control bacterial infections and biofilm formation. In this study, we aimed to identify new species of bacteria with QQ activity. Red Sea sediments were collected either from the close vicinity of seagrass or from areas with no vegetation. We isolated 72 bacterial strains, which were tested for their ability to degrade/inactivate AHL molecules. Chromobacterium violaceum CV026-based bioassay was used for the initial screening of isolates with QQ activity. QQ activity was further quantified using high-performance liquid chromatography-tandem mass spectrometry. We found that these isolates could degrade AHL molecules of different acyl chain lengths as well as modifications. 16S-rRNA sequencing of positive QQ isolates showed that they belonged to three different genera. Specifically, two isolates belonged to the genus Erythrobacter; four, Labrenzia; and one, Bacterioplanes. The genome of one representative isolate from each genus was sequenced, and potential QQ enzymes, namely, lactonases and acylases, were identified. The ability of these isolates to degrade the 3OXOC12-AHLs produced by Pseudomonas aeruginosa PAO1 and hence inhibit biofilm formation was investigated. Our results showed that the isolate VG12 (genus Labrenzia) is better than other isolates at controlling biofilm formation by PAO1 and degradation of different AHL molecules. Time-course experiments to study AHL degradation showed that VG1 (genus Erythrobacter) could degrade AHLs faster than other isolates. Thus, QQ bacteria or enzymes can be used in combination with an antibacterial to overcome antibiotic resistance.