Spermidine Associated with Gut Microbiota Protects Against MRSA Bloodstream Infection by Promoting Macrophage M2 Polarization.

Methicillin-resistant Staphylococcus aureus (MRSA) is a major human pathogen that causes various diseases. Extensive researches highlight the significant role of gut microbiota and its metabolites, particularly spermidine, in infectious diseases. However, the immunomodulatory mechanisms of spermidine in MRSA-induced bloodstream infection remain unclear. Here, we confirmed the protective effects of spermidine in bloodstream infection in mice. Spermidine reduced the bacterial load and expression of inflammatory factors by shifting the macrophage phenotype to an anti-inflammatory phenotype, ultimately prolonging the survival of the infected mice. The protective effect against MRSA infection may rely on the elevated expression of protein tyrosine phosphatase nonreceptor 2 (PTPN2). Collectively, these findings confirm the immunoprotective effects of spermidine via binding to PTPN2 in MRSA bloodstream infection, providing new ideas for the treatment of related infectious diseases.

Radiomics and Clinical Features for Distinguishing Kidney Stone-Associated Urinary Tract Infection: A Comprehensive Analysis of Machine Learning Classification.

Background: This study investigated the abilities of radiomics and clinical feature models to distinguish kidney stone-associated urinary tract infections (KS-UTIs) using computed tomography. Methods: A retrospective analysis was conducted on a single-center dataset comprising computed tomography (CT) scans and corresponding clinical information from 461 patients with kidney stones. Radiomics features were extracted from CT images and underwent dimensionality reduction and selection. Multiple machine learning (Three types of shallow learning and four types of deep learning) algorithms were employed to construct radiomics and clinical models in this study. Performance evaluation and optimal model selection were done using receiver operating characteristic (ROC) curve analysis and Delong test. Univariate and multivariate logistic regression analyzed clinical and radiomics features to identify significant variables and develop a clinical model. A combined model integrating radiomics and clinical features was established. Model performance was assessed by ROC curve analysis, clinical utility was evaluated through decision curve analysis, and the accuracy of the model was analyzed via calibration curve. Results: Multilayer perceptron (MLP) showed higher classification accuracy than other classifiers (area under the curve (AUC) for radiomics model: train 0.96, test 0.94; AUC for clinical model: train 0.95, test 0.91. The combined radiomics-clinical model performed best (AUC for combined model: train 0.98, test 0.95). Decision curve and calibration curve analyses confirmed the model's clinical efficacy and calibration. Conclusions: This study showed the effectiveness of combining radiomics and clinical features from CT scans to identify KS-UTIs. A combined model using MLP exhibited strong classification abilities.

Promotion of RNF168-Mediated Nucleosomal H2A Ubiquitylation by Structurally defined K63-Polyubiquitylated Linker Histone H1.

The chemical synthesis of histones with homogeneous modifications is a potent approach for quantitatively deciphering the functional crosstalk between different post-translational modifications (PTMs). Here, we developed an expedient site-specific (poly)ubiquitylation strategy (CAEPL, Cysteine-Aminoethylation coupled with Enzymatic Protein Ligation), which integrates the Cys-aminoethylation reaction with the process of ubiquitin-activating enzyme UBA1-assisted native chemical ligation. Using this strategy, we successfully prepared monoubiquitylated and K63-linked di- and tri-ubiquitylated linker histone H1.0 proteins, which were incorporated into individual chromatosomes. Quantitative biochemical analysis of different RNF168 constructs on ubiquitylated chromatosomes with different ubiquitin chain lengths demonstrated that K63-linked polyubiquitylated H1.0 could directly stimulate RNF168 ubiquitylation activity by enhancing the affinity between RNF168 and chromatosome. Subsequent cryo-EM structural analysis of the RNF168/UbcH5c-Ub/H1.0-K63-Ub3 chromatosome complex revealed the potential recruitment orientation between RNF168 UDM1 domain and K63-linked ubiquitin chain on H1.0. Finally, we explored the impact of H1.0 ubiquitylation on RNF168 activity in the context of asymmetric H1.0-K63-Ub3 di-nucleosome substrate, revealing a comparable stimulation effect of both the inter- and intra-nucleosomal crosstalk. Overall, our study highlights the significance of access to structurally-defined polyubiquitylated H1.0 by CAEPL strategy, enabling in-depth mechanistic investigations of in-trans PTM crosstalk between linker histone H1.0 and core histone H2A ubiquitylation.

Mechanism of nucleosomal H2A K13/15 monoubiquitination and adjacent dual monoubiquitination by RNF168.

The DNA damage repair regulatory protein RNF168, a monomeric RING-type E3 ligase, has a crucial role in regulating cell fate and DNA repair by specific and efficient ubiquitination of the adjacent K13 and K15 (K13/15) sites at the H2A N-terminal tail. However, understanding how RNF168 coordinates with its cognate E2 enzyme UbcH5c to site-specifically ubiquitinate H2A K13/15 has long been hampered by the lack of high-resolution structures of RNF168 and UbcH5c~Ub (ubiquitin) in complex with nucleosomes. Here we developed chemical strategies and determined the cryo-electron microscopy structures of the RNF168-UbcH5c~Ub-nucleosome complex captured in transient H2A K13/15 monoubiquitination and adjacent dual monoubiquitination reactions, providing a 'helix-anchoring' mode for monomeric E3 ligase RNF168 on nucleosome in contrast to the 'compass-binding' mode of dimeric E3 ligases. Our work not only provides structural snapshots of H2A K13/15 site-specific monoubiquitination and adjacent dual monoubiquitination but also offers a near-atomic-resolution structural framework for understanding pathogenic amino acid substitutions and physiological modifications of RNF168.

Deubiquitinating enzyme USP39 promotes the growth and metastasis of gastric cancer cells by modulating the degradation of RNA-binding protein RBM39.

It has been revealed recently that the RNA-binding motif protein RBM39 is highly expressed in several cancers, which results in poor patient survival. However, how RBM39 is regulated in gastric cancer cells is unknown. Here, affinity purification-mass spectrometry and a biochemical screening are employed to identify the RBM39-interacting proteins and the deubiquitinating enzymes that regulate the RBM39 protein level. Integration of the data obtained from these two approaches uncovers USP39 as the potential deubiquitinating enzyme that regulates RBM39 stability. Bioinformatic analysis discloses that USP39 is increased in gastric cancer tissues and its elevation shortens the duration of overall survival for gastric cancer patients. Biochemical experiments verify that USP39 and RBM39 interact with each other and highly colocalize in the nucleus. Expression of USP39 elevates while USP39 knockdown attenuates the RBM39 protein level and their interaction regulates this modulation and their colocalization. Mechanistic studies reveal that USP39 reduces the K48-linked polyubiquitin chains on RBM39, thus enhancing its stability and increasing the protein level by preventing its proteasomal degradation. USP39 overexpression promotes while its knockdown attenuates the growth, colony formation, migration, and invasion of gastric cancer cells. Interestingly, overexpression of RBM39 partially restores the impact of USP39 depletion, while RBM39 knockdown partially abolishes the effect of USP39 overexpression on the growth, colony formation, migration, and invasion of gastric cancer cells. Collectively, this work identifies the first DUB for RBM39 and elucidates the regulatory functions and the underlying mechanism, providing a possible alternative approach to suppressing RBM39 by inhibiting USP39 in cancer therapy.

Zidovudine in synergistic combination with nitrofurantoin or omadacycline: in vitro and in murine urinary tract or lung infection evaluation against multidrug-resistant Klebsiella pneumoniae.

Limited treatment options and multidrug-resistant (MDR) Klebsiella pneumoniae present a significant therapeutic challenge, underscoring the need for novel approaches. Drug repurposing is a promising tool for augmenting the activity of many antibiotics. This study aimed to identify novel synergistic drug combinations against K. pneumoniae based on drug repurposing. We used the clinically isolated GN 172867 MDR strain of K. pneumoniae to determine the reversal resistance activity of zidovudine (AZT). The combined effects of AZT and various antibiotics, including nitrofurantoin (NIT) and omadacycline (OMC), were examined using the checkerboard method, growth curves, and crystal violet assays to assess biofilms. An in vitro combination activity testing was carried out in 12 isolates of K. pneumoniae. In vivo murine urinary tract and lung infection models were used to evaluate the therapeutic effects of AZT + NIT and AZT + OMC, respectively. The fractional inhibitory concentration index and growth curve demonstrated that AZT synergized with NIT or OMC against K. pneumoniae strains. In addition, AZT + NIT inhibited biofilm formation and cleared mature biofilms. In vivo, compared with untreated GN 172867-infected mice, AZT + NIT and AZT + OMC treatment decreased colony counts in multiple tissues (P < 0.05) and pathological scores in the bladder and kidneys (P < 0.05) and increased the survival rate by 60% (P < 0.05). This study evaluated the combination of AZT and antibiotics to treat drug-resistant K. pneumoniae infections and found novel drug combinations for the treatment of acute urinary tract infections. These findings suggest that AZT may exert significant anti-resistance activity.

Discovery of clinical isolation of drug-resistant Klebsiella pneumoniae with overexpression of OqxB efflux pump as the decisive drug resistance factor.

Background emergence of multidrug-resistant (MDR) bacterial strains is a public health concern that threatens global and regional security. Efflux pump-overexpressing MDR strains from clinical isolates are the best subjects for studying the mechanisms of MDR caused by bacterial efflux pumps. A Klebsiella pneumoniae strain overexpressing the OqxB-only efflux pump was screened from a clinical strain library to explore reverse OqxB-mediated bacterial resistance strategies. We identified non-repetitive clinical isolated K. pneumoniae strains using a matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry clinical TOF-II (Clin-TOF-II) and susceptibility test screening against levofloxacin and ciprofloxacin. And the polymorphism analysis was conducted using pulsed-field gel electrophoresis. Efflux pump function of resistant strains is obtained by combined drug sensitivity test of phenylalanine-arginine beta-naphthylamide (PaßN, an efflux pump inhibitor) and detection with ethidium bromide as an indicator. The quantitative reverse transcription PCR was performed to assess whether the oqxB gene was overexpressed in K. pneumoniae isolates. Additional analyses assessed whether the oqxB gene was overexpressed in K. pneumoniae isolates and gene knockout and complementation strains were constructed. The binding mode of PaßN with OqxB was determined using molecular docking modeling. Among the clinical quinolone-resistant K. pneumoniae strains, one mediates resistance almost exclusively through the overexpression of the resistance-nodulation-division efflux pump, OqxB. Crystal structure of OqxB has been reported recently by N. Bharatham, P. Bhowmik, M. Aoki, U. Okada et al. (Nat Commun 12:5400, 2021, https://doi.org/10.1038/s41467-021-25679-0). The discovery of this strain will contribute to a better understanding of the role of the OqxB transporter in K. pneumoniae and builds on the foundation for addressing the threat posed by quinolone resistance.IMPORTANCEThe emergence of antimicrobial resistance is a growing and significant health concern, particularly in the context of K. pneumoniae infections. The upregulation of efflux pump systems is a key factor that contributes to this resistance. Our results indicated that the K. pneumoniae strain GN 172867 exhibited a higher oqxB gene expression compared to the reference strain ATCC 43816. Deletion of oqxB led a decrease in the minimum inhibitory concentration of levofloxacin. Complementation with oqxB rescued antibiotic resistance in the oqxB mutant strain. We demonstrated that the overexpression of the OqxB efflux pump plays an important role in quinolone resistance. The discovery of strain GN 172867 will contribute to a better understanding of the role of the OqxB transporter in K. pneumoniae and promotes further study of antimicrobial resistance.

Characteristics of stachyose-induced effects on gut microbiota and microbial metabolites in vitro associated with obesity in children.

Childhood obesity presents a serious health concern associated with gut microbiota alterations. Dietary interventions targeting the gut microbiota have emerged as promising strategies for managing obesity in children. This study aimed to elucidate the impact of stachyose (STS) supplementation on the gut microbiota composition and metabolic processes in obese children. Fecal samples were collected from 40 obese children (20 boys and 20 girls) aged between 6 and 15 and in vitro fermentation was conducted with or without the addition of STS, respectively, followed by 16S rRNA amplicon sequencing and analysis of short-chain fatty acids (SCFAs) and gases. Notably, our results revealed that STS supplementation led to significant alterations in gut microbiota composition, including an increase in the abundance of beneficial bacteria such as Bifidobacterium and Faecalibacterium, and a decrease in harmful bacteria including Escherichia-Shigella, Parabacteroides, Eggerthella, and Flavonifractor. Moreover, STS supplementation resulted in changes in SCFAs production, with significant increases in acetate levels and reductions in propionate and propionate, while simultaneously reducing the generation of gases such as H2S, H2, and NH3. The Area Under the Curve (AUC)-Random Forest algorithm and PICRUSt 2 were employed to identify valuable biomarkers and predict associations between the gut microbiota, metabolites, and metabolic pathways. The results not only contribute to the elucidation of STS's modulatory effects on gut microbiota but also underscore its potential in shaping metabolic activities within the gastrointestinal environment. Furthermore, our study underscores the significance of personalized nutrition interventions, particularly utilizing STS supplementation, in the management of childhood obesity through targeted modulation of gut microbial ecology and metabolic function.

Efficient Chemical Synthesis of Multi-Monoubiquitylated and Diubiquitylated Histones by the α-Halogen Ketone-Mediated Strategy.

The chemical synthesis of homogeneously ubiquitylated histones is a powerful approach to decipher histone ubiquitylation-dependent epigenetic regulation. Among the various methods, α-halogen ketone-mediated conjugation chemistry has recently been an attractive strategy to generate single-monoubiquitylated histones for biochemical and structural studies. Herein, we report the use of this strategy to prepare not only dual- and even triple-monoubiquitylated histones but also diubiquitin-modified histones. We were surprised to find that the synthetic efficiencies of multi-monoubiquitylated histones were comparable to those of single-monoubiquitylated ones, suggesting that this strategy is highly tolerant to the number of ubiquitin monomers installed onto histones. The facile generation of a series of single-, dual-, and triple-monoubiquitylated H3 proteins enabled us to evaluate the influence of ubiquitylation patterns on the binding of DNA methyltransferase 1 (DNMT1) to nucleosomes. Our study highlights the potential of site-specific conjugation chemistry to generate chemically defined histones for epigenetic studies.

Viral shedding pattern of severe fever with thrombocytopenia syndrome virus in severely ill patients: A prospective, Multicenter cohort study.

Background: Severe fever with thrombocytopenia syndrome (SFTS) is spreading rapidly in Asia. The pathway of SFTS virus shedding from patient and specific use of personal protective equipments (PPEs) against viral transmission have rarely been reported. The study was to determine SFTS virus (SFTSV) shedding pattern from the respiratory, digestive and urinary tract to outside in patients. Methods: Patients were divided into mild and severe groups in three sentinel hospitals for SFTS in Anhui province from April 2020 to October 2022. SFTSV level from blood, throat swabs, fecal/anal swabs, urine and bedside environment swabs of SFTS patients were detected by qRT-PCR. Specific PPEs were applied in healthcare workers contacting with the patients who had oropharyngeal virus shedding and hemorrhagic signs. Results: A total of 189 SFTSV-confirmed patients were included in the study, 54 patients died (case fatality rate, 28.57 %). Positive SFTSV in throat swabs (T-SFTSV), fecal/anal swabs (F-SFTSV) and urine (U-SFTSV) were detected in 121 (64.02 %), 91 (48.15 %) and 65 (34.4 %) severely ill patients, respectively. The levels of T-SFTSV, F-SFTSV and U-SFTSV were positively correlated with the load of SFTSV in blood. We firstly revealed that SFTSV positive rate of throat swabs were correlated with occurrence of pneumonia and case fatality rate of patients (P < 0.0001). Specific precaution measures were applied by healthcare workers in participating cardiopulmonary resuscitation and orotracheal intubation for severely ill patients with positive T-SFTSV, no event of SFTSV human-to-human transmission occurred after application of effective PPEs. Conclusions: Our research demonstrated SFTSV could shed out from blood, oropharynx, feces and urine in severely ill patients. The excretion of SFTSV from these parts was positively correlated with viral load in the blood. Effective prevention measures against SFTSV human-to-human transmission are needed.

Comparison of efficacies of different treatments for nontuberculous mycobacterial pulmonary disease in Anhui Province, China.

INTRODUCTION: Although nontuberculous mycobacterial (NTM) infection is a common cause of pulmonary disease worldwide, few studies have focused on epidemiological and therapeutic factors related to NTM cases in Anhui Province, China. This retrospective study aimed to identify aetiological and clinical factors, and treatment outcomes of patients with NTM pulmonary disease (NTMPD) in Anhui. METHODOLOGY: Retrospective clinical data obtained from medical records of NTMPD patients seeking care at Anhui Chest Hospital from July 2019 to June 2022 were analyzed. Treatment outcomes were compared between two patient groups: one receiving a standardised NTM treatment regimen and the other receiving precision treatment regimens. RESULTS: Genotypic analysis of 672 clinical NTMPD-associated isolates revealed that most were Mycobacterium intracellulare, while drug-susceptibility test results demonstrated diverse antibiotic resistance profiles for these isolates. Cough was the most common symptom for 101 NTMPD patients. After patients of both groups received treatment, symptoms improved, sputum culture conversion was observed for some patients, imaging findings stabilised; however, no statistically significant intergroup differences in treatment outcomes were found. CONCLUSIONS: In this study, M. intracellulare was the predominant NTM species identified in isolates obtained from NTMPD patients. Drug resistance profiles of our patient isolates were complex, highlighting the need for administration of timely, more effective, standardised treatments for patients with NTMPD in Anhui Province, China.

Structural and mechanistic basis for nucleosomal H2AK119 deubiquitination by single-subunit deubiquitinase USP16.

Epigenetic regulators have a crucial effect on gene expression based on their manipulation of histone modifications. Histone H2AK119 monoubiquitination (H2AK119Ub), a well-established hallmark in transcription repression, is dynamically regulated by the opposing activities of Polycomb repressive complex 1 (PRC1) and nucleosome deubiquitinases including the primary human USP16 and Polycomb repressive deubiquitinase (PR-DUB) complex. Recently, the catalytic mechanism for the multi-subunit PR-DUB complex has been described, but how the single-subunit USP16 recognizes the H2AK119Ub nucleosome and cleaves the ubiquitin (Ub) remains unknown. Here we report the cryo-EM structure of USP16-H2AK119Ub nucleosome complex, which unveils a fundamentally distinct mode of H2AK119Ub deubiquitination compared to PR-DUB, encompassing the nucleosome recognition pattern independent of the H2A-H2B acidic patch and the conformational heterogeneity in the Ub motif and the histone H2A C-terminal tail. Our work highlights the mechanism diversity of H2AK119Ub deubiquitination and provides a structural framework for understanding the disease-causing mutations of USP16.

Lapagyl mitigates UV-induced inflammation and immunosuppression via Foxp3+ Tregs and CCL pathway: A single-cell transcriptomics study.

BACKGROUND: As the largest organ of the body, the skin is constantly subjected to ultraviolet radiation (UVR), leading to inflammations and changes that mirror those seen in chronological aging. Although various small molecule drugs have been explored for treating skin photoaging, they typically suffer from low stability and a high incidence of adverse reactions. Consequently, the continued investigation of photoaging treatments, particularly those utilizing herbal products, remains a critical clinical endeavor. One such herbal product, Lapagyl, is derived from the bark of the lapacho tree and possesses antioxidant efficacies that could be beneficial in combating skin photoaging. PURPOSE: This research aimed to evaluate the efficacy of the herbal product Lapagyl in combating UVR-induced skin photoaging. Additionally, it sought to unravel the mechanisms by which Lapagyl promotes the regeneration of the skin extracellular matrix. METHODS: To investigate whether Lapagyl can alleviate skin aging and damage, a UVR radiation model was established using SKH-1 hairless mice. The dorsal skins of these mice were evaluated for wrinkle formation, texture, moisture, transepidermal water loss (TEWL), and elasticity. Pathological assessments were conducted to determine Lapagyl's efficacy. Additionally, single-cell sequencing and spectrum analysis were employed to elucidate the working mechanisms and primary components of Lapagyl in addressing UVR-induced skin aging and injury. RESULTS: Lapagyl markedly reduced UVR-induced wrinkles, moisture loss, and elasticity decrease in SKH-1 mice. Single-cell sequencing demonstrated that Lapagyl corrected the imbalance in cell proportions caused by UVR, decreased UVR-induced ROS expression, and protected basal and spinous cells from skin damage. Additionally, Lapagyl effectively prevented the entry of inflammatory cells into the skin by reducing CCL8 expression and curtailed the UVR-induced formation of Foxp3+ regulatory T cells (Tregs) in the skin. Both pathological assessments and ex vivo skin model results demonstrated that Lapagyl effectively reduced UVR-induced damage to collagen and elastin. Spectrum analysis identified Salidroside as the primary compound remaining in the skin following Lapagyl treatment. Taken together, our study elucidated the skin protection mechanism of the herbal product Lapagyl against UVR damage at the cellular level, revealing its immunomodulatory effects, with salidroside identified as the primary active compound for skin. CONCLUSION: Our study provided a thorough evaluation of Lapagyl's protective effects on skin against UVR damage, delving into the mechanisms at the cellular level. We discovered that Lapagyl mitigates skin inflammation and immunosuppression by regulating Foxp3+ Tregs and the CCL pathway. These insights indicate that Lapagyl has potential as a novel therapeutic option for addressing skin photoaging.

Proton pump inhibitors stabilize the expression of PD-L1 on cell membrane depending on the phosphorylation of GSK3ß.

BACKGROUND: Preclinical and clinical evidence indicates that proton pump inhibitors (PPIs) may indirectly diminish the microbiome diversity, thereby reducing the effectiveness of immune checkpoint inhibitors (ICIs). Conversely, recent publications have shown that PPIs could potentially enhance the response to ICIs. The precise mechanism through which PPIs modulate the ICIs remains unclear. In this study, we discovered a novel molecular function of PPIs in regulating immune invasion, specifically through inducing PD-L1 translocation in various tumor cells. METHODS: C57BL/6 mice subcutaneous transplantation model is used to verify the potential efficacy of PPIs and PD-L1 antibody. Western blotting analysis and phosphorylated chip are used to verify the alteration of PD-L1-related pathways after being treated with PPIs. The related gene expression is performed by qRT-PCR and luciferase reporter analysis. We also collected 60 clinical patients diagnosed with esophageal cancer or reflux esophagitis and then detected the expression of PD-L1 in the tissue samples by immunohistochemistry. RESULTS: We observed that the IC50 of tumor cells in response to PPIs was significantly higher than that of normal epithelial cells. PPIs significantly increased the expression of PD-L1 on cell membrane at clinically relevant concentrations. Furthermore, pre-treatment with PPIs appeared to synergize the efficiency of anti-PD-L1 antibodies in mouse models. However, PPI administration did not alter the transcription or total protein level of PD-L1 in multiple tumor cells. Using a phosphorylated protein chip, we identified that PPIs enhanced the phosphorylation of GSK3ß, then leading to PD-L1 protein translocation to the cell membranes. The capacity of PPIs to upregulate PD-L1 was negated following GSK3ß knockout. Furthermore, our clinical data showed that the PPIs use resulted in increased PD-L1 expression in esophageal cancer patients. CONCLUSION: We mainly address a significant and novel mechanism that the usage of PPIs could directly induce the expression of PD-L1 by inducing GSK3ß phosphorylation and facilitate primary tumor progression and metastasis.

Traditional paddy field-supported bird diversity ignored by forest-focused protection of ecosystems in tropical China.

Biodiversity in tropical regions is facing threats from agricultural expansion and intensification. Therefore, a promising future for local ecosystem conservation depends not only on traditional protected areas but also on well-managed agricultural landscapes. In this study, we compared the ecological traits of bird species in paddy fields outside of protected areas and natural forests within the protected areas of Xishuangbanna, southern China. There were 148 species in total, of which 98 were in forests and 55 in paddy fields. The abundance of birds in paddy fields was 176 per kilometer, which was much higher than the 60 per kilometer in forests. There were 26 law-protected species observed, half of which were found in each habitat. The main functional groups living in nature reserves are invertivores and frugivores, whereas paddy fields provide habitats for aquatic predator and granivore bird species. Our results indicate that paddy fields act as a refuge for wetland and grassland bird species when natural wetlands disappear, highlighting the urgent need to focus more on wetland protection and eco-friendly agricultural schemes at the landscape scale in future conservation policies.

Erratum: A Novel Pak1/ATF2/miR-132 Signaling Axis Is Involved in the Hematogenous Metastasis of Gastric Cancer Cells.

[This corrects the article DOI: 10.1016/j.omtn.2017.07.005.].

Abiotic natural attenuation of 1,2,3-trichloropropane by natural magnetite under O2 perturbation.

1,2,3-Trichloropropane (TCP) is an emerging groundwater pollutant, but there is a lack of reported studies on the abiotic natural attenuation of TCP by iron minerals. Furthermore, perturbation by O2 is common in the shallow subsurface by both natural and artificial processes. In this study, natural magnetite was selected as the reactive iron mineral to investigate its role in the degradation of TCP under O2 perturbation. The results indicated that the mineral structural Fe(II) on magnetite reacted with dissolved oxygen to generate O2-· and HO·. Both O2-· and HO· contributed to TCP degradation, with O2-· playing a more important role. After 56 days of reaction, 66.7% of TCP was completely dechlorinated. This study revealed that higher magnetite concentrations, smaller magnetite particle sizes, and lower initial TCP concentrations favored TCP degradation. The presence of <10 mg/L natural organic matter (NOM) did not affect TCP degradation. These findings significantly advance our understanding of the abiotic natural attenuation mechanisms facilitated by iron minerals under O2 perturbation, providing crucial insights for the study of natural attenuation.

Prognostic value of poly-microorganisms detected by droplet digital PCR and pathogen load kinetics in sepsis patients: a multi-center prospective cohort study.

This study aimed to investigate the prognostic value of a novel droplet digital polymerase chain reaction (DDPCR) assay in sepsis patients. In this prospective cohort study, univariable and multivariable Cox regressions were used to assess risk factors for 28-day mortality. We also monitored pathogen load together with clinical indicators in a subgroup of the cohort. A total of 107 sepsis patients with positive baseline DDPCR results were included. Detection of poly-microorganisms [adjusted hazard ratio (HR) = 3.19; 95% confidence interval (CI) = 1.34-7.62; P = 0.009], high Charlson Comorbidity Index (CCI) score (adjusted HR = 1.14; 95% CI = 1.01-1.29; P = 0.041), and Sequential Organ Failure Assessment (SOFA) score (adjusted HR = 1.18; 95% CI = 1.05-1.32; P = 0.005) at baseline were independent risk factors for 28-day mortality while initial pathogen load was not associated (adjusted HR = 1.17; 95% CI = 0.82-1.66; P = 0.385). Among 63 patients with serial DDPCR results, an increase in pathogen load at days 6-8 compared to baseline was a risk factor for 28-day mortality (P = 0.008). Also, pathogen load kinetics were significantly different between day-28 survivors and nonsurvivors (P = 0.022), with a decline overtime only in survivors and an increase from days 3 and 4 to days 6-8 in nonsurvivors. Using DDPCR technique, we found that poly-microorganisms detected and increased pathogen load a week after sepsis diagnosis were associated with poor prognosis.IMPORTANCEThis prospective study was initiated to explore the prognostic implications of a novel multiplex PCR assay in sepsis. Notably, our study was the largest cohort of sepsis with droplet digital polymerase chain reaction pathogen monitoring to date, allowing for a comprehensive evaluation of the prognostic significance of both pathogen species and load. We found that detection of poly-microorganisms was an independent risk factors for 28-day mortality. Also, pathogen load increase 1 week after sepsis diagnosis was a risk factor for 28-day mortality, and differential pathogen load kinetics were identified between day-28 survivors and nonsurvivors. Overall, this study demonstrated that pathogen species and load were highly correlated with sepsis prognosis. Patients exhibiting conditions mentioned above face a more adverse prognosis, suggesting the potential need for an escalation of antimicrobial therapy.Registered at ClinicalTrials.gov (NCT05190861).

Mitigating Tetracycline antibiotic contamination in chicken manure using ex situ fermentation system.

Excessive use of tetracycline antibiotics in poultry farming results in significant concentrations of these drugs and tetracycline resistance genes (TRGs) in chicken manure, impacting both environmental and human health. Our research represents the first investigation into the removal dynamics of chlortetracycline (CTC) and TRGs in different layers of an ex situ fermentation system (EFS) for chicken waste treatment. By pinpointing and analyzing dominant TRGs-harboring bacteria and their interactions with environmental variables, we've closed an existing knowledge gap. Findings revealed that CTC's degradation half-lives spanned 3.3-5.8 days across different EFS layers, and TRG removal efficiency ranged between 86.82% and 99.52%. Network analysis highlighted Proteobacteria and Actinobacteria's essential roles in TRGs elimination, whereas Chloroflexi broadened the potential TRG hosts in the lower layer. Physical and chemical conditions within the EFS influenced microbial community diversity, subsequently impacting TRGs and integrons. Importantly, our study reports that the middle EFS layer exhibited superior performance in eliminating CTC and key TRGs (tetW, tetG, and tetX) as well as intI2. Our work transcends immediate health and environmental remediation by offering insights that encourage sustainable agriculture practices.

Breather wave solutions on the Weierstrass elliptic periodic background for the (2 + 1)-dimensional generalized variable-coefficient KdV equation.

In this paper, the Nth Darboux transformations for the (2+1)-dimensional generalized variable-coefficient Koretweg-de Vries (gvcKdV) equation are proposed. By using the Lamé function method, the generalized Lamé-type solutions for the linear spectral problem associated with the gvcKdV equation with the static and traveling Weierstrass elliptic ℘-function potentials are derived, respectively. Then, the nonlinear wave solutions for the gvcKdV equation on the static and traveling Weierstrass elliptic ℘-function periodic backgrounds under some constraint conditions are obtained, respectively, whose evolutions and dynamical properties are also discussed. The results show that the degenerate solutions on the periodic background can be obtained by taking the limits of the half-periods ω1,ω2 of ℘(x), and the evolution curves of nonlinear wave solutions on the periodic background are determined by the coefficients of the gvcKdV equations.