IL-4 activates macrophages to adopt distinct phenotypes associated with clearance of helminth infections and tissue repair, but the phenotype depends on the cellular lineage of these macrophages. The ...molecular basis of chromatin remodeling in response to IL-4 stimulation in tissue-resident and monocyte-derived macrophages is not understood. In this study, we find that IL-4 activation of different lineages of peritoneal macrophages in mice is accompanied by lineage-specific chromatin remodeling in regions enriched with binding motifs of the pioneer transcription factor PU.1. PU.1 motif is similarly associated with both tissue-resident and monocyte-derived IL-4-induced accessible regions but has different lineage-specific DNA shape features and predicted cofactors. Mutation studies based on natural genetic variation between C57BL/6 and BALB/c mouse strains indicate that accessibility of these IL-4-induced regions can be regulated through differences in DNA shape without direct disruption of PU.1 motifs. We propose a model whereby DNA shape features of stimulation-dependent genomic elements contribute to differences in the accessible chromatin landscape of alternatively activated macrophages on different genetic backgrounds that may contribute to phenotypic variations in immune responses.
Staphylococcus aureus is responsible for various diseases in humans, and recurrent infections are commonly observed. S. aureus produces an array of bicomponent pore-forming toxins that target and ...kill leukocytes, known collectively as the leukocidins. The contribution of these leukocidins to impair the development of anti-S. aureus adaptive immunity and facilitate reinfection is unclear. Using a murine model of recurrent bacteremia, we demonstrate that infection with a leukocidin mutant results in increased levels of anti-S. aureus antibodies compared with mice infected with the WT parental strain, indicating that leukocidins negatively impact the generation of anti-S. aureus antibodies in vivo. We hypothesized that neutralizing leukocidin-mediated immune subversion by vaccination may shift this host-pathogen interaction in favor of the host. Leukocidin-immunized mice produce potent leukocidin-neutralizing antibodies and robust Th1 and Th17 responses, which collectively protect against bloodstream infections. Altogether, these results demonstrate that blocking leukocidin-mediated immune evasion can promote host protection against S. aureus bloodstream infection.
Considerable data implicate oxidative damage in influenza pathogenesis. We examined temporal changes in oxidative damage using accurate biomarkers in an adult cohort with acute influenza infection ...and their relationships with clinical parameters. Clinical information and blood samples were collected during their acute illness and 3 months later. A fatigue questionnaire was administered 3 months following influenza infection. Thirty-five patients (mean age, 34 years) with polymerase chain reaction-confirmed influenza A infection were included; all patients returned for follow-up assessments. Adjusted levels of plasma F2-isoprostanes, total hydroxyeicosatetraenoic products (HETEs), 7β-hydroxycholesterol and 7-ketocholesterol, serum gamma-glutamyltransferase, and high-sensitivity C-reactive protein (hsCRP) were increased during the acute illness compared with age-matched controls. Despite clinical recovery, levels of these biomarkers remained higher at month 3 compared with controls. A proportion of patients had persistent symptoms such as fatigue (23%), myalgia (14%), and arthralgia (11%) at month 3. Patients with significant fatigue had higher baseline levels of plasma F2-isoprostanes, F4-neuroprostanes, and total HETEs compared to those without fatigue. By contrast, patients with persistent arthralgia and myalgia had higher baseline levels of serum hsCRP compared to those without these symptoms. Our observations lead to the hypothesis that oxidative damage participates in the pathogenesis of influenza infection and postinfectious fatigue.
This review provides a quantitative description of the nano-adsorbent processing and its viability against wastewater detoxification by extracting heavy metal ions. The impact of nano-adsorbent ...functionalities on specific essential attributes such as the surface area, segregation, and adsorption capacity were comprehensively evaluated. A detailed analysis has been presented on the characteristics of nanomaterials through their limited resistance to adsorb some heavy metal ions. Experimental variables such as the adsorbent dosage, pH, substrate concentration, response duration, temperature, and electrostatic force that influence the uptake of metal ions have been studied. Besides, separate models for the adsorption kinetics and isothermal adsorption have been investigated to understand the mechanism behind adsorption. Here, we reviewed the different adsorbent materials with nano-based techniques for the removal of heavy metals from wastewater and especially highlighted the nano adsorption technique. The influencing factors such as pH, temperature, dosage time, sorbent dosage, adsorption capacities, ion concentration, and mechanisms related to the removal of heavy metals by nano composites are highlighted. Lastly, the application potentials and challenges of nano adsorption for environmental remediation are discussed. This critical review would benefit engineers, chemists, and environmental scientists involved in the utilization of nanomaterials for wastewater treatment.
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•This review provides a quantitative description of the nano-adsorbent against wastewater detoxification.•Highlighted the various nano adsorption techniques.•Challenges of nano adsorption for environmental remediation are discussed.
•Understanding spatial and temporal trends of diversity is crucial for conservation.•This study analyses long-term data from 1986 to 2020 on Singapore reefs.•Taxonomic and phylogenetic diversity ...increased but functional diversity declined.•Reefs shifted towards dominance of stress-tolerant traits such as slow growth.•Trait-based approaches at finer taxonomic resolution will enhance reef monitoring.
Coral reefs provide a multitude of ecosystem functions owing to the high levels of biodiversity they host. Coral species, as the foundation of shallow-water reefs, differ in their contributions toward the functioning of the ecosystem due in part to the disparate phylogenetic histories of scleractinian lineages. Understanding the spatial patterns and temporal trajectories of these biodiversity facets, as well as their interrelationships, is critical for more targeted conservation strategies in the face of widespread habitat degradation and climate change. Here, we analyse long-term benthic data spanning 1986 through 2020 on coral reefs in Singapore, which have been impacted by decades of urbanisation-related and thermal stressors, to test for differences between coral biodiversity facets—specifically, taxonomic, phylogenetic (evolutionary relatedness between species), and functional (occupancy of functional trait space) richness and diversity. Analyses show that taxonomic and phylogenetic richness and diversity measures increased over the 35-year period despite declines during major bleaching events. Yet, while taxonomic and phylogenetic diversity increased, functional richness and diversity declined over the same period. Community-weighted trait measures indicate a shift towards dominance of more stress-tolerant traits such as slower growth rates, smaller corallite sizes, and massive colony forms. Together, these trends highlight the effects of chronic urban stressors alongside major bleaching events impacting reef assemblages. Critically, such assemblage shifts and functional diversity declines were masked by increasing taxonomic diversity, which is most commonly assessed, and could erode ecosystem resilience. The temporal decoupling of the biodiversity facets examined here underscore the need for more comprehensive monitoring of reefs through a combination of trait-based approaches alongside traditional field surveys at finer taxonomic resolution.
A key step which involves the cyclization of delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine to the bicyclic ring structure of isopenicillin N in the penicillin and cephalosporin biosynthetic ...pathway, is catalyzed by isopenicillin N synthase (IPNS). In this study, an IPNS gene from Streptomyces lipmanii NRRL 3584 (slIPNS) was cloned via PCR-based homology cloning, sequenced and expressed in Escherichia coli. Soluble slIPNS was overexpressed up to 21% of total soluble protein, and verified to be functionally active when in an IPNS enzymatic assay. Sequence comparison of the slIPNS gene obtained (excluding the consensus primer sequences) with another cloned IPNS from S. lipmanii 16884.3, revealed one three-nucleotide deletion and three closely-spaced single nucleotide deletions. Furthermore, this paper also reports the first instance of the usage of PCR as an alternative and rapid strategy for IPNS cloning using consensus primers.
While microbiomes in industrialized societies are well characterized, indigenous populations with traditional lifestyles have microbiomes that are more akin to those of ancient humans. However, ...metagenomic data in these populations remains scarce, and the association with soil-transmitted helminth infection status is unclear. Here, we sequenced 650 metagenomes of indigenous Malaysians from five villages with different prevalence of helminth infections.
Individuals from villages with higher prevalences of helminth infections have more unmapped reads and greater microbial diversity. Microbial community diversity and composition were most strongly associated with different villages and the effects of helminth infection status on the microbiome varies by village. Longitudinal changes in the microbiome in response to albendazole anthelmintic treatment were observed in both helminth infected and uninfected individuals. Inference of bacterial population replication rates from origin of replication analysis identified specific replicating taxa associated with helminth infection.
Our results indicate that helminth effects on the microbiota were highly dependent on context, and effects of albendazole on the microbiota can be confounding for the interpretation of deworming studies. Furthermore, a substantial quantity of the microbiome remains unannotated, and this large dataset from an indigenous population associated with helminth infections is a valuable resource for future studies. Video Abstract.
Over 75% of clinical microbiological infections are caused by bacterial biofilms that grow on wounds or implantable medical devices. This work describes the development of a new ...poly(diallyldimethylammonium chloride) (PDADMAC)/alginate-coated gold nanorod (GNR/Alg/PDADMAC) that effectively disintegrates the biofilms of
(
), a prominent pathogen responsible for hospital-acquired infections.
GNR was synthesised via seed-mediated growth method, and the resulting nanoparticles were coated first with Alg and then PDADMAC. FTIR, zeta potential, transmission electron microscopy, and UV-Vis spectrophotometry analysis were performed to characterise the nanoparticles. The efficacy and speed of the non-coated GNR and GNR/Alg/PDADMAC in disintegrating
-preformed biofilms, as well as their in vitro biocompatibility (L929 murine fibroblast) were then studied.
The synthesised GNR/Alg/PDADMAC (mean length: 55.71 ± 1.15 nm, mean width: 23.70 ± 1.13 nm, aspect ratio: 2.35) was biocompatible and potent in eradicating preformed biofilms of methicillin-resistant (MRSA) and methicillin-susceptible
(MSSA) when compared to triclosan, an antiseptic used for disinfecting
colonisation on abiotic surfaces in the hospital. The minimum biofilm eradication concentrations of GNR/Alg/PDADMAC (MBEC
for MRSA biofilm = 0.029 nM; MBEC
for MSSA biofilm = 0.032 nM) were significantly lower than those of triclosan (MBEC
for MRSA biofilm = 10,784 nM; MBEC
for MRSA biofilm 5967 nM). Moreover, GNR/Alg/PDADMAC was effective in eradicating 50% of MRSA and MSSA biofilms within 17 min when used at a low concentration (0.15 nM), similar to triclosan at a much higher concentration (50 µM). Disintegration of MRSA and MSSA biofilms was confirmed by field emission scanning electron microscopy and confocal laser scanning microscopy.
These findings support the potential application of GNR/Alg/PDADMAC as an alternative agent to conventional antiseptics and antibiotics for the eradication of medically important MRSA and MSSA biofilms.
Microbiologically influenced corrosion (MIC), commonly known as biocorrosion, is a destructive phenomenon that can be initiated by the bioactivities of microbes. It can occur in the diesel mixture ...storage tank, especially due to the presence of biodiesel, because the biodegradability characteristic of biodiesel results in the enhancement of microbial growth and also the MIC process. The Bacillus genus, such as B. licheniformis, is one of the microbes that is detected in the diesel storage tank and can contribute to MIC pitting phenomena. This study examined biocorrosion in ST-37 carbon steel by B. licheniformis, with variation of biodiesel concentrations (B0, B15, B20, B30, and B100). The results showed that the bioactivity of B. licheniformis increased in all biodiesel concentration cultures compared to the sterile medium. Then the highest corrosion rate was found for samples dipped in the B15-blend. However, the corrosion rate decreased on the specimen immersed in the equal and higher than B20-blend, due to thicker and more uniform biofilm formation. In addition, B. licheniformis can produce γ-polyglutamate, which acts as a corrosion inhibitor. This shows that B. licheniformis-mediated biocorrosion may promote the use of the B100 product as an environmentally friendly biofuel. However, it is important to consider the effects of B. licheniformis on diesel blend medium, especially biodegradation. Furthermore, the study of the production, extraction and implementation of γ-polyglutamate as a green corrosion inhibitor may be very useful in the future as a corrosion prevention solution.
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•The concentration of biodiesel can influence the phenomena of biocorrosion in the storage tank. .•B. licheniformis is detected in the storage tank of the diesel blend.•TPC, gravimetry, SEM, digital microscope, and FTIR analysis are used.•The formation of biofilm on the metal surface can influence the pitting corrosion attack.•B. licheniformis can produce γ-polyglutamate, which can inhibit corrosion.
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