Metagenomics of high-altitude groundwater reveal different health risks associated with antibiotic-resistant pathogens and bacterial resistome in the latitudinal gradient.

Groundwater on the Tibetan Plateau is a critical water resource to people in Asia. However, its prevalence of antibiotic-resistant pathogens (ARPs), bacterial resistome and their driving factors remain unknown. Using metagenomics analysis, a hotspot of antibiotic-resistance genes (ARGs) and last-resort ARGs (LARGs) with a total of 639 subtypes was identified in the groundwater. Importantly, 164 metagenome-assembled genomes (MAGs) which possessed both ARGs and virulence factors (VFs) were assigned as potential ARPs, with the most abundant species being Acinetobacter johnsonii and Acinetobacter pittii. A total of 157 potential ARPs, involving Escherichia coli, were predicted as "natural" ARGs supercarriers. Thirty-six ARPs dominated by the genus Acinetobacter and Pseudomonas were found to harbour LARGs. Co-localizations of the ARG-mobile genetic elements (MGEs) showed that MGEs were significantly associated with ARGs in the ARPs, which suggests ARPs play a prominent role in ARG dissemination. Notably, latitudinal gradient is a driving factor in the occurrence of ARGs and ARPs. The average abundances of ARGs and ARP decreased as the latitude increased, with the highest abundance occurring in the region between 28.6◦N and 29.5◦N. MetaCompare further revealed health risks associated with the resistome decreased as the latitudes increased. These findings indicated different health risks associated with ARPs and bacterial resistome in latitudinal gradient groundwater. They raise the concerns of mitigating ARPs risk in groundwater on the Tibetan Plateau.

CRISPR/Cas9-based engineered Escherichia coli biosensor for sensitive and specific detection of Cd(II) in drinking water.

Cadmium (Cd) is a ubiquitous pollutant that poses a potential threat to human health. Monitoring Cd(II) in drinking water has significant implications for preventing potential threats of Cd(II) to human. However, the weak signal output and response to nontarget interference limit the detection of Cd(II) using bacterial biosensors. In this study, to enable sensitive and specific detection of Cd(II) in water, a stable whole-cell biosensor, K12-PMP-luxCDABE-△cysI, was constructed in a dual-promoter mode by fusing the mercury promoter Pmer, regulatory gene merR(m), and luciferase gene luxCDABE into the E.coli chromosome based on CRISPR/Cas9 gene editing technology. By knocking out the cadmium-resistance-gene cysI, the sensitivity of the biosensor to Cd(II) was further enhanced. The constructed E. coli biosensor K12-PMP-luxCDABE-△cysI exhibited good nonlinear responses to 0.005-2 mg/L Cd(II). Notably, among the three constructed E. coli biosensor, it exhibited the strongest fluorescence intensity, with the limit of detection meeting the allowable limit for Cd(II) in drinking water. Simultaneously, it could specifically detect Cd(II). Nontarget metal ions, such as Zn(II), Hg(II), and Pb(II), did not affect its performance. Furthermore, it exhibited superior performance in detecting Cd(II) in real drinking water samples by avoiding background interference, and showed excellent stability with the relative standard deviation under 5%. Thus, K12-PMP-luxCDABE-△cysI holds promise as a potential tool for the detection of Cd(II) in drinking water.

Quantitative Trait Locus Mapping for Plant Height and Branch Number in CCRI70 Recombinant Inbred Line Population of Upland Cotton (Gossypium hirsutum).

Upland cotton accounts for a high percentage (95%) of the world's cotton production. Plant height (PH) and branch number (BN) are two important agronomic traits that have an impact on improving the level of cotton mechanical harvesting and cotton yield. In this research, a recombinant inbred line (RIL) population with 250 lines developed from the variety CCRI70 was used for constructing a high-density genetic map and identification of quantitative trait locus (QTL). The results showed that the map harbored 8298 single nucleotide polymorphism (SNP) markers, spanning a total distance of 4876.70 centimorgans (cMs). A total of 69 QTLs for PH (9 stable) and 63 for BN (11 stable) were identified and only one for PH was reported in previous studies. The QTLs for PH and BN harbored 495 and 446 genes, respectively. Combining the annotation information, expression patterns and previous studies of these genes, six genes could be considered as potential candidate genes for PH and BN. The results could be helpful for cotton researchers to better understand the genetic mechanism of PH and BN development, as well as provide valuable genetic resources for cotton breeders to manipulate cotton plant architecture to meet future demands.

The prevalence and risk factors of work-related musculoskeletal disorders among nurses in China: A systematic review and meta-analysis.

BACKGROUND: Work-related musculoskeletal disorders significantly impact the job performance and quality of life of nursing personnel in China, necessitating an understanding of their prevalence and risk factors to enhance occupational health and improve medical safety. OBJECTIVE: To systematically evaluate the prevalence and risk factors of work-related musculoskeletal disorders among clinical nurses in China. DESIGN: Systematic literature review and meta-analysis. METHODS: A computerized search was conducted on databases, including the China Knowledge Resource Integrated Database, Wanfang Database, China Biomedical Literature Database, Weipu Database, Embase, PubMed, Web of Science, the Cochrane Library, and CINAHL, covering studies from inception to February 28, 2024, addressing the risk factors for work-related musculoskeletal disorders among clinical nursing professionals in China. The meta-analysis was performed using Review Manager 5.4 and Stata 14 software. RESULTS: The analysis included 23 articles, involving a total of 21,042 cases, and revealed a prevalence rate of 79 % (95 % CI: 73 %-84 %) for work-related musculoskeletal disorders among clinical nursing staff in China. Subgroup analysis revealed that the prevalence of work-related musculoskeletal disorders was highest among those with length of service >15 years, at 87 %; the 31-40 age group had a higher prevalence than other age groups, at 85 %; female nurses exhibited a prevalence rate of 80 %, surpassing male nurses at 77 %, while surgical nurses had a higher prevalence rate (83 %) than those in other departments. The most affected body parts were the neck (58 %), waist (57 %), shoulders (49 %), and back (35 %). Identified risk factors for work-related musculoskeletal disorders among clinical nurses in China included age >35 years (OR = 1.69, 95 % CI: 1.16-2.45), length of service ≥10 years (OR = 3.30, 95 % CI: 1.84-5.92), marital status (married) (OR = 2.19, 95 % CI: 1.91-2.50), heavy workload (OR = 2.46, 95 % CI: 1.25-4.83), weekly work hours >40 h (OR = 1.50, 95 % CI: 1.34-1.67), daily work hours >8 h (OR = 1.71, 95 % CI: 1.32-2.21), strong sense of work fatigue (OR = 1.47, 95 % CI: 1.22-1.76), and high night shift frequency (OR = 1.81, 95 % CI: 1.62-2.02). Regular physical exercise was found to be a protective factor (OR = 0.68, 95 % CI: 0.56-0.82). CONCLUSION: The overall prevalence of work-related musculoskeletal disorders among clinical nursing staff in China was 79 %. Age >35 years, length of service ≥10 years, marital status (married), heavy workload, weekly work hours >40 h, daily work hours >8 h, strong sense of work fatigue, and night shift frequency were identified as risk factors. Nursing administrators and staff can take proactive measures against the aforementioned factors to reduce the risk of illness and ensure the safety of medical care. REGISTRATION: PROSPERO: CRD42023479433.

Emergence of colistin-resistant Stenotrophomonas maltophilia with high virulence in natural aquatic environments.

The presence of Stenotrophomonas maltophilia in aquatic environments poses great health risks to immunocompromised individuals because of its multidrug resistance and resultant high mortality. However, a significant gap exists in the isolation and understanding of colistin-resistant S. maltophilia in aquatic environments. In this study, nine colistin-resistant S. maltophilia strains isolated from natural lakes were explored, and their phylogenetic relationship, biofilm formation, virulence, and antibiotic resistance profiles and underlying genetic determinants were assessed. After genome analysis, besides known multi-locus sequence typing (MLST) of ST532, new assigned ST965 and ST966 which phylogenetically clustered into soil isolates were found firstly. All the isolates exhibited resistance to multiple antibiotics, including aminoglycosides, beta-lactams, tetracyclines, and even colistin, with the highest minimum inhibitory concentration (MIC) against colistin reaching 640 mg/L. Comparative genomic analysis revealed aph(3')-Iic, blaL1, tetT, phoP, mcr-3, arnA, pmrE, and efflux pump genes as the genetic determinants underlying this multidrug resistance. Notably, the biofilm-forming capacities of the newly discovered ST965 and ST966 isolates were significant stronger than those of the known ST532 isolates (p < 0.01), resulting in the death of over 50 % of the Galleria mellonella population within 1 day of injection. The ST965 isolates demonstrated the highest virulence against G. mellonella, followed by the ST966 isolates and ST532 isolates which was phylogenetically clustered with clinical isolates, indicating that the novel S. maltophilia strains of ST965 and ST966 may pose considerable health risks to humans. Our findings provide insights into colistin-resistant S. maltophilia in aquatic environments and raise concerns about the health risks posed by the newly assigned sequence types of colistin-resistant S. maltophilia with potential high virulence in natural aquatic environments.

A mica filter enables bacterial enrichment from large volumes of natural water for sensitive monitoring of pathogens by nanopore sequencing.

Nanopore sequencing is extremely promising for the high-throughput detection of pathogenic bacteria in natural water; these bacteria may be transmitted to humans and cause waterborne infectious diseases. However, the concentration of pathogenic bacteria in natural water is too low to be detected directly by nanopore sequencing. Herein, we developed a mica filter to enrich over 85% of bacteria from > 10 L of natural water in 100 min, which led to a 102-fold improvement in the assay limits of the MinION sequencer for assessing pathogenic bacteria. Correspondingly, the sequencing time of S. Typhi detection at a concentration as low as 105 CFU/L was reduced from traditional 48 h to 3 h. The bacterial adsorption followed pseudo-first-order kinetics and the successful adsorption of bacteria to the mica filter was confirmed by scanning electron microscopy and Fourier infrared spectroscopy et al. The mica filter remained applicable to a range of water samples whose quality parameters were within the EPA standard limits for freshwater water. The mica filter is thus an effective tool for the sensitive and rapid monitoring of pathogenic bacteria by nanopore sequencing, which can provide timely alerts for waterborne transmission events.

Carbonaceous particulate matter promotes the horizontal transfer of antibiotic resistance genes.

There is growing concern about the transfer of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in airborne particulate matter. In this study, we investigated the effects of various types of carbonaceous particulate matter (CPM) on the transfer of ARGs in vitro. The results showed that CPM promoted the transfer of ARGs, which was related to the concentration and particle size. Compared with the control group, the transfer frequency was 95.5, 74.7, 65.4, 14.7, and 3.8 times higher in G (graphene), CB (carbon black), NGP (nanographite powder), GP1.6 (graphite powder 1.6 micron), and GP45 (graphite powder 45 micron) groups, respectively. Moreover, the transfer frequency gradually increased with the increase in CPM concentration, while there was a negative relationship between the CPM particle size and conjugative transfer frequency. In addition, the results showed that CPM could promote the transfer of ARGs by increasing ROS, as well as activating the SOS response and expression of conjugative transfer-related genes (trbBp, trfAp, korA, kroB, and trbA). These findings are indicative of the potential risk of CPM for the transfer of ARGs in the environment, enriching our understanding of environmental pollution and further raising awareness of environmental protection.

Mitochondrial dysfunction of peripheral blood mononuclear cells is associated with lung carcinogenesis.

The composition, quantity, and function of peripheral blood mononuclear cells (PBMCs) are closely correlated with tumorigenesis. However, the mechanisms of PBMCs in lung cancer are not clear. Mitochondria are energy factories of cells, and almost all cellular functions rely on their energy metabolism level. The present study aimed to test whether the mitochondrial function of PBMCs directly determines their tumor immune monitoring function. We recruited 211 subjects, including 105 healthy controls and 106 patients with recently diagnosed with lung cancer. The model of lung carcinogenesis induced by BaP was used in animal experiment, and the Bap carcinogenic metabolite, Benzo(a)pyren-7,8-dihydrodiol-9,10-epoxide (BPDE), was used in cell experiment. We found that mitochondrial function of PBMCs decreased significantly in patients with new lung cancer, regardless of age. In vivo, BaP caused PBMC mitochondrial dysfunction in mice before the appearance of visible malignant tissue. Moreover, mitochondrial function decreased significantly in mice with lung cancers induced by BaP compared to those without lung cancer after BaP intervention. In vitro, BPDE also induced mitochondrial dysfunction and reduced the aggressiveness of PBMCs toward cancer cells. Furthermore, the changes in mitochondrial energy metabolism gene expression caused by BPDE are involved in this process. Thus, the mitochondrial function of PBMCs is a potential prognostic biomarker or therapeutic target to improve clinical outcomes in patients with lung cancer.

Comparative analysis of chlorine-resistant bacteria after chlorination and chloramination in drinking water treatment plants.

Chlorine-resistant bacteria (CRB) in drinking water treatment plants (DWTPs) jeopardize water quality and pose a potential risk to human health. However, the specific response of CRB to chlorination and chloramination remains uncharacterized. Therefore, we analyzed 16 S rRNA sequencing data from water samples before and after chlorination and chloramination taken between January and December 2020. Proteobacteria and Firmicutes dominated all finished water samples. After chloramination, Acinetobacter, Pseudomonas, Methylobacterium, Ralstonia, and Sphingomonas were the dominant CRB, whereas Ralstonia, Bacillus, Acinetobacter, Pseudomonas, and Enterococcus were prevalent after chlorination. Over 75% of the CRB e.g. Acinetobacter, Pseudomonas, Bacillus, and Enterococcus were shared between the chlorination and chloramination, involving potentially pathogens, such as Acinetobacter baumannii and Pseudomonas aeruginosa. Notably, certain genera such as Faecalibacterium, Geobacter, and Megasphaera were enriched as strong CRB after chloramination, whereas Vogesella, Flavobacterium, Thalassolituus, Pseudoalteromonas, and others were enriched after chlorination according to LEfSe analysis. The shared CRB correlated with temperature, pH, and turbidity, displaying a seasonal pattern with varying sensitivity to chlorination and chloramination in cold and warm seasons. These findings enhance our knowledge of the drinking water microbiome and microbial health risks, thus enabling better infectious disease control through enhanced disinfection strategies in DWTPs.

Hub Genes in Stable QTLs Orchestrate the Accumulation of Cottonseed Oil in Upland Cotton via Catalyzing Key Steps of Lipid-Related Pathways.

Upland cotton is the fifth-largest oil crop in the world, with an average supply of nearly 20% of vegetable oil production. Cottonseed oil is also an ideal alternative raw material to be efficiently converted into biodiesel. However, the improvement in kernel oil content (KOC) of cottonseed has not received sufficient attention from researchers for a long time, due to the fact that the main product of cotton planting is fiber. Previous studies have tagged QTLs and identified individual candidate genes that regulate KOC of cottonseed. The regulatory mechanism of oil metabolism and accumulation of cottonseed are still elusive. In the current study, two high-density genetic maps (HDGMs), which were constructed based on a recombinant inbred line (RIL) population consisting of 231 individuals, were used to identify KOC QTLs. A total of forty-three stable QTLs were detected via these two HDGM strategies. Bioinformatic analysis of all the genes harbored in the marker intervals of the stable QTLs revealed that a total of fifty-one genes were involved in the pathways related to lipid biosynthesis. Functional analysis via coexpression network and RNA-seq revealed that the hub genes in the co-expression network that also catalyze the key steps of fatty acid synthesis, lipid metabolism and oil body formation pathways (ACX4, LACS4, KCR1, and SQD1) could jointly orchestrate oil accumulation in cottonseed. This study will strengthen our understanding of oil metabolism and accumulation in cottonseed and contribute to KOC improvement in cottonseed in the future, enhancing the security and stability of worldwide food supply.

QTL Verification and Candidate Gene Screening of Fiber Quality and Lint Percentage in the Secondary Segregating Population of Gossypium hirsutum.

Fiber quality traits, especially fiber strength, length, and micronaire (FS, FL, and FM), have been recognized as critical fiber attributes in the textile industry, while the lint percentage (LP) was an important indicator to evaluate the cotton lint yield. So far, the genetic mechanism behind the formation of these traits is still unclear. Quantitative trait loci (QTL) identification and candidate gene validation provide an effective methodology to uncover the genetic and molecular basis of FL, FS, FM, and LP. A previous study identified three important QTL/QTL cluster loci, harboring at least one of the above traits on chromosomes A01, A07, and D12 via a recombinant inbred line (RIL) population derived from a cross of Lumianyan28 (L28) × Xinluzao24 (X24). A secondary segregating population (F2) was developed from a cross between L28 and an RIL, RIL40 (L28 × RIL40). Based on the population, genetic linkage maps of the previous QTL cluster intervals on A01 (6.70-10.15 Mb), A07 (85.48-93.43 Mb), and D12 (0.40-1.43 Mb) were constructed, which span 12.25, 15.90, and 5.56 cM, with 2, 14, and 4 simple sequence repeat (SSR) and insertion/deletion (Indel) markers, respectively. QTLs of FL, FS, FM, and LP on these three intervals were verified by composite interval mapping (CIM) using WinQTL Cartographer 2.5 software via phenotyping of F2 and its derived F2:3 populations. The results validated the previous primary QTL identification of FL, FS, FM, and LP. Analysis of the RNA-seq data of the developing fibers of L28 and RIL40 at 10, 20, and 30 days post anthesis (DPA) identified seven differentially expressed genes (DEGs) as potential candidate genes. qRT-PCR verified that five of them were consistent with the RNA-seq result. These genes may be involved in regulating fiber development, leading to the formation of FL, FS, FM, and LP. This study provides an experimental foundation for further exploration of these functional genes to dissect the genetic mechanism of cotton fiber development.

An effective hybrid feature selection using entropy weight method for automatic sleep staging.

Objective. Sleep staging is the basis for sleep quality assessment and diagnosis of sleep-related disorders. In response to the inadequacy of traditional manual judgement of sleep stages, using machine learning techniques for automatic sleep staging has become a hot topic. To improve the performance of sleep staging, numerous studies have extracted a large number of sleep-related characteristics. However, there are redundant and irrelevant features in the high-dimensional features that reduce the classification accuracy. To address this issue, an effective hybrid feature selection method based on the entropy weight method is proposed in this paper for automatic sleep staging.Approach. Firstly, we preprocess the four modal polysomnography (PSG) signals, including electroencephalogram (EEG), electrooculogram (EOG), electrocardiogram (ECG) and electromyogram (EMG). Secondly, the time domain, frequency domain and nonlinear features are extracted from the preprocessed signals, with a total of 185 features. Then, in order to acquire characteristics of the multi-modal signals that are highly correlated with the sleep stages, the proposed hybrid feature selection method is applied to choose effective features. This method is divided into two stages. In stage I, the entropy weight method is employed to combine two filter methods to build a subset of features. This stage evaluates features based on information theory and distance metrics, which can quickly obtain a subset of features and retain the relevant features. In stage II, Sequential Forward Selection is used to evaluate the subset of features and eliminate redundant features. Further more, to achieve better performance of classification, an ensemble model based on support vector machine, K-nearest neighbor, random forest and multilayer perceptron is finally constructed for classifying sleep stages.Main results. The experiment using the Cyclic Alternating Pattern (CAP) sleep database is performed to assess the performance of the method proposed in this paper. The proposed hybrid feature selection method chooses only 30 features highly correlated to sleep stages. The accuracy, F1 score and Kappa coefficient of 6 class sleep staging reach 88.86%, 83.15% and 0.8531%, respectively.Significance. Experimental results show the effectiveness of the proposed method compared to the existing state-of-the-art studies. It greatly reduces the number of features required while achieving outstanding auto-sleep staging results.

Landscape of antibiotic resistance genes and bacterial communities in groundwater on the Tibetan Plateau, and distinguishing their difference with low-altitude counterparts.

Groundwater is a vital source of drinking water for Tibetans. Antibiotic resistance genes (ARGs) and bacterial communities in groundwater on the Tibetan Plateau remain unclear. Furthermore, the characterization of their differences between high-altitude and low-altitude groundwater is still unrevealed. Herein, 32 groundwater samples were collected on the plateau, and intra- and extracellular ARGs (iARGs and eARGs), and bacterial communities were characterised through qPCR assays to 19 ARGs and 16S rRNA sequencing. It showed top four abundant intra- and extracellular last-resort ARGs (LARGs) were blaOXA-48, mcr-1, vanA, and vanB, whereas dominant common ARGs (CARGs) were tetA and ermB, respectively. CARGs had higher abundances than LARGs, and iARGs were more frequently detected than eARGs. Proteobacteria, an invasive resident phylum, and Firmicutes dominated eDNA release. Network analysis revealed all observed LARGs co-occurred with pathogenic and non-pathogenic bacteria. Community diversity was significantly associated with longitude and elevation, while nitrate correlated with ARGs. Comparative analysis demonstrated eARG frequencies and abundances were higher at high altitudes than at low altitudes. Additionally, Acinetobacter and Pseudomonas specifically dominated at high altitudes. This study reveals the widespread prevalence of ARGs, particularly LARGs, in groundwater on the less-disturbed Tibetan Plateau and underlines the potential risks associated with the LARG-carrying bacteria. ENVIRONMENTAL IMPLICATION: Antibiotic resistance genes (ARGs), which are defined as emerging environmental contaminants, are becoming a global concern due to their ability to confer antibiotic resistance to pathogens. Our findings highlight the prevalence of ARGs, particularly LARGs, in groundwater on the Tibetan Plateau, and the possibility that naturally-occurring pathogenic and non-pathogenic bacteria carry multiple LARGs. In addition, we further reveal differences in the distribution of ARGs and bacterial community between high-altitude and low-altitude groundwater. Collectively, our findings offer an important insight into the potential public risks related to groundwater on the Tibetan Plateau.

Beauvericin exerts an anti-tumor effect on hepatocellular carcinoma by inducing PI3K/AKT-mediated apoptosis.

Beauvericin is a world-spread mycotoxin isolated from the traditional Chinese medicine, Bombyx batryticatus (BB), which has been widely used to treat various neoplastic diseases. This study investigated the anti-hepatocellular carcinoma (HCC) activity of beauvericin and its potential mechanism. In this study, H22-bearing mice were intraperitoneally injected with 3, 5, 7 mg/kg of beauvericin once per-week over a three-week period. TUNEL staining determined the extent of tumor apoptosis induced by beauvericin. ELISA kits detected the level of IL-2, Perforin, and TNF-α, IFN-γ level in the serum. H22 hepatoma cells were exposed to beauvericin (5, 10, and 20 µmol/L) to investigate the underlying pathway. CCK-8 assay was used to observe the influence of beauvericin on the growth of H22 cells. Flow cytometry was used to detect the cell apoptosis and ROS level. Western blotting was performed to detect apoptotic and PI3K/AKT pathway protein production. The results showed that beauvericin could remarkably inhibit the growth of HCC in mice, combined with elevated TNF-α and IL-2. In vitro, beauvericin significantly promoted the generation of ROS, up-regulated Bax/Bcl-2 ratio and cleaved caspase-9, cleaved caspase-3 levels, down-regulated p-PI3K/PI3K ratio, p-AKT/AKT ratio, promoted the apoptosis of H22 cells, and inhibited the growth of H22 cells. Remarkably, treatment with PI3K/AKT activator (740Y-P and SC79) could prevent beauvericin-induced H22 cell apoptosis. These findings collectively indicate that beauvericin inhibits HCC growth by inducing apoptosis via the PI3K/AKT pathway.

Spatial and temporal analysis of the seasonal dynamics of antibiotic resistance gene occurrence in recreational marine water.

People who engage in water sports in recreational marine water may be at high risk of exposure to hazardous antibiotic-resistant bacteria (ARB). However, information on the contribution of specific sources to ARB contamination in recreational marine water is still lacking. Here, we carried out monthly analyses of antibiotic resistance genes (ARGs), pathogenic bacteria and 16S rRNA sequencing data at the First Bathing Beach in Qingdao. The sampling sites were divided into four areas: swimming area, intermediate area, polluted area, and sewage outlet. Correlations between ARGs and bacterial communities among sampling sites were explored by spatial and temporal analysis. We found that all of 21 important ARG types were detected in the swimming area, with aadA (1.3 × 106 ± 2.7 × 106 genomic copies/L) and sul2 (4.3 × 105 ± 5.9 × 105 genomic copies/L) at the highest concentration. Most ARGs were detected at highest frequency and concentration in the sewage outlet and decreased from there to the swimming area. ARG correlation between these two areas was positive only in the cold season, suggesting that sewage was the main source of ARG pollution in the swimming area during that period. The ARGs ermA(1) and vanA were detected at highest frequency and concentration in the swimming area and were significantly correlated with the intestinal pathogen Enterococcus, which was more abundant here than in the surrounding areas during the warm season. Co-occurrence analysis of bacterial genera and ARGs showed that six genera were commonly correlated with ARGs in all sampling areas in the cold season, while none were found in the warm season. Our findings indicate that ARG pollution in the swimming area was also driven by sources other than sewage, especially in the warm season, which is the peak tourist season in Qingdao. These results provide a valuable basis for the implementation of effective strategies to control ARG risks in recreational waters.

Antidepressant exposure as a source of disinfectant resistance in waterborne bacteria.

The emergence of disinfectant-resistant pathogens in water is a major threat to public health. However, whether human-consumed pharmaceuticals can induce bacterial resistance to disinfectants remains unclear. Herein, Escherichia coli was exposed to 12 antidepressants, and susceptibility of antidepressant-induced chloramphenicol (CHL)-resistant mutants to disinfectants was tested. Whole genome sequencing, global transcriptomic sequencing, and real-time quantitative polymerase chain reaction were used to elucidate the underlying mechanisms. We observed that duloxetine, fluoxetine, amitriptyline, and sertraline significantly increased the mutation frequency of E. coli against CHL by 15- to 2948-fold. The resultant mutants increased the average MIC50 of sodium hypochlorite, benzalkonium bromide, and triclosan roughly 2- to 8-fold. Consistently, marRAB and acrAB-tolC genes, together with ABC transporter genes (e.g., yddA, yadG, yojI, and mdlA), were triggered to increase the efflux of disinfectants out of the cell, while ompF was inhibited, reducing disinfectant penetration into the cell. Additionally, the occurrence of DNA mutations in marR and acrR in the mutants was observed, potentially resulting in increased synthesis of the AcrAB-TolC pump. This study indicates that pharmaceutical exposure may create disinfectant-resistant bacteria, which may then be released into water systems, providing novel insights into the potential source of water-borne disinfectant-resistant pathogens.

Benzene induces spleen injury through the B cell receptor signaling pathway.

Benzene is a toxic environmental pollutant that disrupts the immune system in humans. Benzene exposure reduces the abundance of immune cells in multiple immune organs; however, the biological mechanisms underlying benzene-induced immunotoxicity has not been elucidated. In this study, benzene was used to develop mouse model for immune dysfunction. A significant decrease in IgG, IL-2 and IL-6 levels, an increase in oxidative stress and spleen injury were observed after benzene exposure in a dose-dependent manner. Quantitative proteomics revealed that benzene-induced immune dysfunction was associated with deregulation of the B cell receptor (BCR) signaling pathway. Benzene exposure suppressed the expression of CD22, BCL10 and NF-κb p65. Also, a significant decrease in proliferation and an increase in apoptosis of splenic lymphocytes were found after benzene exposure. Moreover, we found that benzene exposure increased mitochondrial reactive oxygen species (mito-ROS) and decreased adenosine triphosphate (ATP). Overall, we revealed the damaging effects of benzene on spleen-related immune function and the underlying biological mechanism, involving the disruption of BCR signaling pathway, NF-κB deactivation, and mitochondrial dysfunction.

Simulated Gastric Acid Promotes the Horizontal Transfer of Multidrug Resistance Genes across Bacteria in the Gastrointestinal Tract at Elevated pH Levels.

The assessment of factors that can promote the transmission of antibiotic resistance genes (ARGs) across bacteria in the gastrointestinal tract is in great demand to understand the occurrence of infections related to antibiotic-resistant bacteria (ARB) in humans. However, whether acid-resistant enteric bacteria can promote ARG transmission in gastric fluid under high-pH conditions remains unknown. This study assessed the effects of simulated gastric fluid (SGF) at different pH levels on the RP4 plasmid-mediated conjugative transfer of ARGs. Moreover, transcriptomic analysis, measurement of reactive oxygen species (ROS) levels, assessment of cell membrane permeability, and real-time quantitative assessment of the expression of key genes were performed to identify the underlying mechanisms. The frequency of conjugative transfer was the highest in SGF at pH 4.5. Antidepressant consumption and certain dietary factors further negatively impacted this situation, with 5.66-fold and 4.26-fold increases in the conjugative transfer frequency being noted upon the addition of sertraline and 10% glucose, respectively, compared with that in the control group without any additives. The induction of ROS generation, the activation of cellular antioxidant systems, increases in cell membrane permeability, and the promotion of adhesive pilus formation were factors potentially contributing to the increased transfer frequency. These findings indicate that conjugative transfer could be enhanced under certain circumstances in SGF at elevated pH levels, thereby facilitating ARG transmission in the gastrointestinal tract. IMPORTANCE The low pH of gastric acid kills unwanted microorganisms, in turn affecting their inhabitation in the intestine. Hence, studies on the factors that influence antibiotic resistance gene (ARG) propagation in the gastrointestinal tract and on the underlying mechanisms are limited. In this study, we constructed a conjugative transfer model in the presence of simulated gastric fluid (SGF) and found that SGF could promote the dissemination of ARGs under high-pH conditions. Furthermore, antidepressant consumption and certain dietary factors could negatively impact this situation. Transcriptomic analysis and a reactive oxygen species assay revealed the overproduction of reactive oxygen species as a potential mechanism by which SGF could promote conjugative transfer. This finding can help provide a comprehensive understanding of the bloom of antibiotic-resistant bacteria in the body and create awareness regarding the risk of ARG transmission due to certain diseases or an improper diet and the subsequent decrease in gastric acid levels.

Genome-wide characterization of trichome birefringence-like genes provides insights into fiber yield improvement.

Cotton is an important fiber crop. The cotton fiber is an extremely long trichome that develops from the epidermis of an ovule. The trichome is a general and multi-function plant organ, and trichome birefringence-like (TBL) genes are related to trichome development. At the genome-wide scale, we identified TBLs in four cotton species, comprising two cultivated tetraploids (Gossypium hirsutum and G. barbadense) and two ancestral diploids (G. arboreum and G. raimondii). Phylogenetic analysis showed that the TBL genes clustered into six groups. We focused on GH_D02G1759 in group IV because it was located in a lint percentage-related quantitative trait locus. In addition, we used transcriptome profiling to characterize the role of TBLs in group IV in fiber development. The overexpression of GH_D02G1759 in Arabidopsis thaliana resulted in more trichomes on the stems, thereby confirming its function in fiber development. Moreover, the potential interaction network was constructed based on the co-expression network, and it was found that GH_D02G1759 may interact with several genes to regulate fiber development. These findings expand our knowledge of TBL family members and provide new insights for cotton molecular breeding.

Reducing the carbon emission from agricultural production in China: do land transfer and urbanization matter?

Urbanization and land transfer have triggered a profound reform of the Chinese agricultural sector since reform and opening, leading to a continuous rise in agricultural carbon emissions. However, the impact of urbanization and land transfer on agricultural carbon emissions is not widely understood. Therefore, based on the panel data covering 30 provinces (cities) in China from 2005 to 2019, we adopted a panel autoregressive distributed lag model and a vector autoregressive model to empirically explore the causal relationship between land transfer, urbanization, and agricultural carbon emissions. The main conclusions are as follows: (1) Land transfer can significantly reduce carbon emissions from agricultural production in the long run, while urbanization has a positive effect on agricultural carbon emissions. (2) In the short run, land transfer has a significant positive impact on agricultural carbon emissions, and urbanization also has a positive impact on the carbon emissions of agricultural production, but in insignificant ways. (3) There is two-way causality between land transfer and agricultural carbon emission, and between urbanization and land transfer is the same, but urbanization is the one-way Granger cause of agricultural carbon emissions. Finally, some suggestions are provided for low-carbon agriculture development: the government should encourage the transfer of land management rights and guide high-quality resources to gather in green agriculture.