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1.
Cell Rep Med ; 5(9): 101734, 2024 Sep 17.
Article in English | MEDLINE | ID: mdl-39293400

ABSTRACT

Staphylococcus aureus is a major human pathogen, yet the immune factors that protect against infection remain elusive. High titers of opsonic IgG antibodies, achieved in preclinical animal immunization studies, have consistently failed to provide protection in humans. Here, we investigate antibody responses to the conserved S. aureus surface glycan wall teichoic acid (WTA) and detect the presence of WTA-specific IgM and IgG antibodies in the plasma of healthy individuals. Functionally, WTA-specific IgM outperforms IgG in opsonophagocytic killing of S. aureus and protects against disseminated S. aureus bacteremia through passive immunization. In a clinical setting, patients with S. aureus bacteremia have significantly lower WTA-specific IgM but similar IgG levels compared to healthy controls. Importantly, low WTA-IgM levels correlate with disease mortality and impaired bacterial opsonization. Our findings may guide risk stratification of hospitalized patients and inform future design of antibody-based therapies and vaccines against serious S. aureus infection.


Subject(s)
Antibodies, Bacterial , Immunoglobulin G , Immunoglobulin M , Polysaccharides , Staphylococcal Infections , Staphylococcus aureus , Humans , Staphylococcus aureus/immunology , Immunoglobulin M/immunology , Immunoglobulin M/blood , Staphylococcal Infections/immunology , Staphylococcal Infections/microbiology , Immunoglobulin G/immunology , Immunoglobulin G/blood , Antibodies, Bacterial/immunology , Antibodies, Bacterial/blood , Polysaccharides/immunology , Teichoic Acids/immunology , Animals , Female , Male , Phagocytosis/immunology , Bacteremia/immunology , Bacteremia/microbiology , Mice , Adult , Middle Aged , Opsonization/immunology
2.
J Infect Dis ; 2024 May 14.
Article in English | MEDLINE | ID: mdl-38743812

ABSTRACT

BACKGROUND: The cell envelope of Staphylococcus aureus contains two major secondary cell wall glycopolymers: capsular polysaccharide (CP) and wall teichoic acid (WTA). Both the CP and the WTA are attached to the cell wall and play distinct roles in S. aureus colonization, pathogenesis, and bacterial evasion of host immune defenses. OBJECTIVE: We aimed to investigate whether CP interferes with WTA-mediated properties. METHODS: Strains with natural heterogeneous expression of CP, strains with homogeneous high CP expression and CP-deficient strains were compared to WTA deficient controls regarding WTA dependent phage binding, cell adhesion, IgG deposition, and virulence in vivo. RESULTS: WTA-mediated phage adsorption, specific antibody deposition and cell adhesion were negatively correlated with CP expression. WTA, but not CP, enhanced the bacterial burden in a mouse abscess model, while CP overexpression resulted in intermediate virulence in vivo. CONCLUSIONS: CP protects the bacteria from WTA-dependent opsonization and phage binding. This protection comes at the cost of diminished adhesion to host cells. The highly complex regulation and mostly heterogeneous expression of CP has probably evolved to ensure the survival and optimal physiological adaptation of the bacterial population as a whole.

3.
Pathogens ; 13(5)2024 May 07.
Article in English | MEDLINE | ID: mdl-38787238

ABSTRACT

Campylobacter jejuni is a zoonotic bacterium with the capacity to invade the epithelial cells during the pathogenic process. Several bacterial factors have been identified to contribute to this process, but our knowledge is still very limited about the response of the host. To reveal the major routes of this response, a whole-transcriptome analysis (WTA) was performed where gene expressions were compared between the 1st and the 3rd hours of internalization in INT407 epithelial cells. From the 41,769 human genes tested, altogether, 19,060 genes were shown through WTA to be influenced to different extents. The genes and regulation factors of transcription (296/1052; 28%), signal transduction (215/1052; 21%), apoptosis (153/1052; 15%), immune responses (97/1052; 9%), transmembrane transport (64/1052; 6%), cell-cell signaling (32/1052; 3%), cell-cell adhesions (29/1052; 3%), and carbohydrate metabolism (28/1052; 3%) were the most affected biological functions. A striking feature of the gene expression of this stage of the internalization process is the activation of both immune functions and apoptosis, which convincingly outlines that the invaded cell faces a choice between death and survival. The seemingly balanced status quo between the invader and the host is the result of a complex process that also affects genes known to be associated with postinfectious pathological conditions. The upregulation of TLR3 (3.79×) and CD36 (2.73×), two general tumor markers, and SERPINEB9 (11.37×), FNDC1 (7.58×), and TACR2 (8.84×), three factors of tumorigenesis, confirms the wider pathological significance of this bacterium.

4.
Saudi J Biol Sci ; 31(4): 103956, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38404538

ABSTRACT

The target of the present work is to study the most abundant carbohydrate-active enzymes (CAZymes) of glycosyltransferase (GT) class, which are encoded by fungiome genes present in the rhizospheric soil of the plant species Moringa oleifera. The datasets of this CAZy class were recovered using metagenomic whole shotgun genome sequencing approach, and the resultant CAZymes were searched against the KEGG pathway database to identify function. High emphasis was given to the two GT families, GT4 and GT2, which were the highest within GT class in the number and abundance of gene queries in this soil compartment. These two GT families harbor CAZymes playing crucial roles in cell membrane and cell wall processes. These CAZymes are responsible for synthesizing essential structural components such as cellulose and chitin, which contribute to the integrity of cell walls in plants and fungi. The CAZyme beta-1,3-glucan synthase of GT2 family accumulates 1,3-ß-glucan, which provides elasticity as well as tensile strength to the fungal cell wall. Other GT CAZymes contribute to the biosynthesis of several compounds crucial for cell membrane and wall integrity, including lipopolysaccharide, e.g., lipopolysaccharide N-acetylglucosaminyltransferase, cell wall teichoic acid, e.g., alpha-glucosyltransferase, and cellulose, e.g., cellulose synthase. These compounds also play pivotal roles in ion homeostasis, organic carbon mineralization, and osmoprotection against abiotic stresses in plants. This study emphasizes the major roles of these two CAZy GT families in connecting the structure and function of cell membranes and cell walls of fungal and plant cells. The study also sheds light on the potential occurrence of tripartite symbiotic relationships involving the plant, rhizospheric bacteriome, and fungiome via the action of CAZymes of GT4 and GT2 families. These findings provide valuable insights towards the generation of innovative agricultural practices to enhance the performance of crop plants in the future.

5.
Antimicrob Agents Chemother ; 68(3): e0162723, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38349162

ABSTRACT

Methicillin-resistant Staphylococcus aureus (MRSA) strains are a major challenge for clinicians due, in part, to their resistance to most ß-lactams, the first-line treatment for methicillin-susceptible S. aureus. A phenotype termed "NaHCO3-responsiveness" has been identified, wherein many clinical MRSA isolates are rendered susceptible to standard-of-care ß-lactams in the presence of physiologically relevant concentrations of NaHCO3, in vitro and ex vivo; moreover, such "NaHCO3-responsive" isolates can be effectively cleared by ß-lactams from target tissues in experimental infective endocarditis (IE). One mechanistic impact of NaHCO3 exposure on NaHCO3-responsive MRSA is to repress WTA synthesis. This NaHCO3 effect mimics the phenotype of tarO-deficient MRSA, including sensitization to the PBP2-targeting ß-lactam, cefuroxime (CFX). Herein, we further investigated the impacts of NaHCO3 exposure on CFX susceptibility in the presence and absence of a WTA synthesis inhibitor, ticlopidine (TCP), in a collection of clinical MRSA isolates from skin and soft tissue infections (SSTI) and bloodstream infections (BSI). NaHCO3 and/or TCP enhanced susceptibility to CFX in vitro, by both minimum inhibitor concentration (MIC) and time-kill assays, as well as in an ex vivo simulated endocarditis vegetations (SEV) model, in NaHCO3-responsive MRSA. Furthermore, in experimental IE (presumably in the presence of endogenous NaHCO3), pre-exposure to TCP prior to infection sensitized the NaHCO3-responsive MRSA strain (but not the non-responsive strain) to enhanced clearances by CFX in target tissues. These data support the notion that NaHCO3 is acting similarly to WTA synthesis inhibitors, and that such inhibitors have potential translational applications in the treatment of certain MRSA strains in conjunction with specific ß-lactam agents.


Subject(s)
Endocarditis, Bacterial , Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections , Humans , Anti-Bacterial Agents/pharmacology , Cefuroxime/pharmacology , Bicarbonates/pharmacology , Staphylococcus aureus , beta-Lactams/pharmacology , Endocarditis, Bacterial/drug therapy , Microbial Sensitivity Tests , Staphylococcal Infections/drug therapy
6.
Front Med (Lausanne) ; 11: 1297001, 2024.
Article in English | MEDLINE | ID: mdl-38357647

ABSTRACT

Introduction: Single-cell multi-omics studies, such as multidimensional transcriptomics (whole transcriptomic analysis, WTA), and surface marker analysis (antibody sequencing, AbSeq), have turned out to be valuable techniques that offer inaccessible possibilities for single-cell profiling of mRNA, lncRNA, and proteins. Methods: We used this technique to understand the dynamics of mRNA and protein-level differences in healthy, COVID-19-infected and recovered individuals using peripheral blood mononuclear cells (PBMCs). Our results demonstrate that compared to mRNA expression, protein abundance is a better indicator of the disease state. Results: We demonstrate that compared to mRNA expression, protein abundance is a better indicator of the disease state. We observed high levels of cell identity and regulatory markers, CD3E, CD4, CD8A, CD5, CD7, GITR, and KLRB1 in healthy individuals, whereas markers related to cell activation, CD38, CD28, CD69, CD62L, CD14, and CD16 elevated in the SARS-CoV-2 infected patients at both WTA and AbSeq levels. Curiously, in recovered individuals, there was a high expression of cytokine and chemokine receptors (CCR5, CCR7, CCR4, CXCR3, and PTGRD2). We also observed variations in the expression of markers within cell populations under different states. Discussion: Furthermore, our study emphasizes the significance of employing an oligo-based method (AbSeq) that can help in diagnosis, prognosis, and protection from disease/s by identifying cell surface markers that are unique to different cell types or states. It also allows simultaneous study of a vast array of markers, surpassing the constraints of techniques like FACS to query the vast repertoire of proteins.

7.
J Prev (2022) ; 45(1): 47-85, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37999883

ABSTRACT

Despite concerted efforts to enforce smoke-free laws in various countries, nonsmokers, particularly women and children, continue to be exposed to daily secondhand smoke (SHS), resulting in significant health risks. While existing studies have assessed the health effects of numerous diseases, the quantification of SHS spillovers remains understudied. This research employs choice experiments and contingent valuation techniques to rigorously quantify the attributes of SHS health risks, with a specific emphasis on facilitating cross-country comparisons. Our investigation reveals that nonsmoking individuals in the United Kingdom exhibit an attitude of indifference towards a proposed policy offering increased disposable income as compensation for SHS exposure. Conversely, nonsmoking Americans express a contrary perspective. Furthermore, our study demonstrates that nonsmoking Americans attribute a higher value to SHS health risks compared to their British counterparts. Consequently, this research uncovers a hitherto unexplored dimension of health risk-related behaviors. These findings hold the potential to significantly contribute to the development of future smoke-free policies, offering valuable insights that can inform policy decisions and address the persistent challenges associated with SHS exposure, particularly among vulnerable populations.


Subject(s)
Smoke-Free Policy , Tobacco Smoke Pollution , Child , Humans , Female , United States/epidemiology , Tobacco Smoke Pollution/adverse effects , Non-Smokers , Employment , White
8.
Cell Rep ; 42(9): 113154, 2023 09 26.
Article in English | MEDLINE | ID: mdl-37725513

ABSTRACT

Bacteria use quorum sensing (QS) to coordinate group behavior in response to cell density, and some bacterial viruses (phages) also respond to QS. In Staphylococcus aureus, the agr-encoded QS system relies on accumulation of auto-inducing cyclic peptides (AIPs). Other staphylococci also produce AIPs of which many inhibit S. aureus agr. We show that agr induction reduces expression of tarM, encoding a glycosyltransferase responsible for α-N-acetylglucosamine modification of the major S. aureus phage receptor, the wall teichoic acids. This allows lytic phage Stab20 and related phages to infect and kill S. aureus. However, in mixed communities, producers of inhibitory AIPs like S. haemolyticus, S. caprae, and S. pseudintermedius inhibit S. aureus agr, thereby impeding phage infection. Our results demonstrate that cross-species interactions dramatically impact phage susceptibility. These interactions likely influence microbial ecology and impact the efficacy of phages in medical and biotechnological applications such as phage therapy.


Subject(s)
Bacteriophages , Staphylococcal Infections , Humans , Staphylococcus aureus/metabolism , Bacteriophages/metabolism , Staphylococcus/metabolism , Glycosyltransferases/metabolism , Bacterial Proteins/metabolism , Quorum Sensing
9.
Methods Mol Biol ; 2660: 69-83, 2023.
Article in English | MEDLINE | ID: mdl-37191791

ABSTRACT

The rapid emergence of spatial multi-omics technologies in recent years has revolutionized biomedical research. Among these, the Digital Spatial Profiler (DSP, commercialized by nanoString) has become one of the dominant technologies in spatial transcriptomics and proteomics and has assisted in deconvoluting complex biological questions. Based on our practical experience in the past 3 years with DSP, we share here a detailed hands-on protocol and key handling notes that will allow the broader community to optimize their work procedure.


Subject(s)
Gene Expression Profiling , RNA , RNA/genetics , Gene Expression Profiling/methods , Paraffin Embedding , Tissue Fixation , Formaldehyde
10.
Microbiol Spectr ; 11(3): e0038023, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37154757

ABSTRACT

DNA methylation is a defense that microorganisms use against extreme environmental stress, and improving resistance against environmental stress is essential for industrial actinomycetes. However, research on strain optimization utilizing DNA methylation for breakthroughs is rare. Based on DNA methylome analysis and KEGG pathway assignment in Streptomyces roseosporus, we discovered an environmental stress resistance regulator, TagR. A series of in vivo and in vitro experiments identified TagR as a negative regulator, and it is the first reported regulator of the wall teichoic acid (WTA) ABC transport system. Further study showed that TagR had a positive self-regulatory loop and m4C methylation in the promoter improved its expression. The ΔtagR mutant exhibited better hyperosmotic resistance and higher decanoic acid tolerance than the wild type, which led to a 100% increase in the yield of daptomycin. Moreover, enhancing the expression of the WTA transporter resulted in better osmotic stress resistance in Streptomyces lividans TK24, indicating the potential for wide application of the TagR-WTA transporter regulatory pathway. This research confirmed the feasibility and effectiveness of mining regulators of environmental stress resistance based on the DNA methylome, characterized the mechanism of TagR, and improved the resistance and daptomycin yield of strains. Furthermore, this research provides a new perspective on the optimization of industrial actinomycetes. IMPORTANCE This study established a novel strategy for screening regulators of environmental stress resistance based on the DNA methylome and discovered a new regulator, TagR. The TagR-WTA transporter regulatory pathway improved the resistance and antibiotic yield of strains and has the potential for wide application. Our research provides a new perspective on the optimization and reconstruction of industrial actinomycetes.


Subject(s)
Daptomycin , Streptomyces , Epigenome , Anti-Bacterial Agents , Streptomyces/genetics , Streptomyces/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism
11.
Int J Sports Physiol Perform ; 18(5): 547-552, 2023 May 01.
Article in English | MEDLINE | ID: mdl-36965488

ABSTRACT

PURPOSE: An understanding of an athlete's total daily energy expenditure (TEE) is necessary to inform nutritional strategies, particularly where daily training and competitive demands are highly variable. This observational case series assessed the TEE of elite tennis players during high-level competition. METHODS: Senior female singles participants (FS: n = 3; 21 [1] y; ranked  Women's Tennis Association [WTA] top 125-375), an FS junior (n = 1; 16 y; ranked WTA top 350), and a men's doubles player (n = 1; 26 y; ranked Association of Tennis Professionals [ATP] top 5) were assessed for TEE (using the doubly labeled water method) during a 9- to 14-day period, which included training, Wimbledon Championships, WTA/ATP International Tournaments, Junior/Senior International Tennis Federation, and Wimbledon Junior Championships. One female (FS3) did not exercise from day 4 following injury. RESULTS: TEE for men's doubles was 4586 kcal·d-1 (67 kcal·kg-1 fat-free mass [FFM]; daily activity 98 [74] min). Noninjured adult female participants' TEEs were 3396 and 3948 kcal·d-1 (66 and 81 kcal·kg-1 FFM; daily activity durations were 139 [84] min and 150 [66] min, respectively), while TEE for the injured athlete was 2583 kcal·d-1 (45.7 kcal·kg-1; daily nonexercise activity duration was <45 min). The junior player TEE was 3988 kcal·d-1 (78.2 kcal·kg-1 FFM; daily activity of 131 [66] min). CONCLUSION: This observational case series positions tennis as a highly energetically demanding sport with variability evident between individuals (ie, TEE between 60 and 90 kcal·kg-1 FFM). Accordingly, nutritional strategies that promote sufficient energy availability should be emphasized with individual variability suitably assessed prior to prescription.


Subject(s)
Sports , Tennis , Male , Adult , Humans , Female , Water , Energy Metabolism , Adenosine Triphosphate
12.
Front Med (Lausanne) ; 10: 1282065, 2023.
Article in English | MEDLINE | ID: mdl-38162890

ABSTRACT

Introduction: Kidney transplantation has become the most cost-effective treatment for patients with end-stage kidney disease (ESKD) and offers them the highest quality of life. Yet, kidney donation is often inaccessible due to cultural and traditional beliefs about organ donation. The goal of our study is to assess the value of kidney donation using the Willingness to Accept (WTA) technique. We also aim to understand the factors influencing an individual's willingness to donate an organ. Methods: A self-administered survey was completed by 985 participants from the general public. The quantitative method and survey design that were chosen used descriptive, correlational, nonparametric, and multivariate statistical tests. Results: Most of the respondents, 895 (90.9%) are not willing to donate a kidney while alive. Four hundred and five (41.1%) of the respondents are not willing to donate a kidney after their death, while the rest are willing to donate their kidney after their death without financial compensation. The same attitude applies to the donation of a kidney from their relatives. Significant predictors from the results of the logistic regression model in predicting the lowest (minimal) amount that will encourage donation of one kidney after death were: Marital status; Nationality; Adi card holder; Knowing people who need a kidney donation; confidence in the medical staff; and consideration of the family's opinions regarding organ donation. Discussion: Using cost benefit analysis (CBA), with the aim of evaluating the willingness of individuals to accept payment for innovative medical procedures, such as kidney donation, allows an assessment of the perceived value of the medical procedure and enables policymakers to decide whether to allocate funds or offer subsidies for kidney donation, given the limited healthcare resources available. During our research, we found that most participants did not support the commercialization of organs. Our recommendation for policymakers and health professionals is to continue providing adequate funding for kidney donations and to implement educational programs aimed at improving attitudes towards organ donation.

13.
Microbiol Spectr ; 10(6): e0342222, 2022 12 21.
Article in English | MEDLINE | ID: mdl-36377886

ABSTRACT

Methicillin-resistant Staphylococcus aureus (MRSA) strains pose major treatment challenges due to their innate resistance to most ß-lactams under standard in vitro antimicrobial susceptibility testing conditions. A novel phenotype among MRSA, termed "NaHCO3 responsiveness," where certain strains display increased susceptibility to ß-lactams in the presence of NaHCO3, has been identified among a relatively large proportion of MRSA isolates. One underlying mechanism of NaHCO3 responsiveness appears to be related to decreased expression and altered functionality of several genes and proteins involved in cell wall synthesis and maturation. Here, we studied the impact of NaHCO3 on wall teichoic acid (WTA) synthesis, a process intimately linked to peptidoglycan (PG) synthesis and functionality, in NaHCO3-responsive versus -nonresponsive MRSA isolates. NaHCO3 sensitized responsive MRSA strains to cefuroxime, a specific penicillin-binding protein 2 (PBP2)-inhibitory ß-lactam known to synergize with early WTA synthesis inhibitors (e.g., ticlopidine). Combining cefuroxime with ticlopidine with or without NaHCO3 suggested that these latter two agents target the same step in WTA synthesis. Further, NaHCO3 decreased the abundance and molecular weight of WTA only in responsive strains. Additionally, NaHCO3 stimulated increased autolysis and aberrant cell division in responsive strains, two phenotypes associated with disruption of WTA synthesis. Of note, studies of key genes involved in the WTA biosynthetic pathway (e.g., tarO, tarG, dltA, and fmtA) indicated that the inhibitory impact of NaHCO3 on WTA biosynthesis in responsive strains likely occurred posttranslationally. IMPORTANCE MRSA is generally viewed as resistant to standard ß-lactam antibiotics. However, a NaHCO3-responsive phenotype is observed in a substantial proportion of clinical MRSA strains in vitro, i.e., isolates which demonstrate enhanced susceptibility to standard ß-lactam antibiotics (e.g., oxacillin) in the presence of NaHCO3. This phenotype correlates with increased MRSA clearance in vivo by standard ß-lactam antibiotics, suggesting that patients with infections caused by such MRSA strains might be amenable to treatment with ß-lactams. The mechanism(s) behind this phenotype is not fully understood but appears to involve mecA-PBP2a production and maturation axes. Our study adds significantly to this body of knowledge in terms of additional mechanistic targets of NaHCO3 in selected MRSA strains. This investigation demonstrates that NaHCO3 has direct impacts on S. aureus wall teichoic acid biosynthesis in NaHCO3-responsive MRSA. These findings provide an additional target for new agents being designed to synergistically kill MRSA using ß-lactam antibiotics.


Subject(s)
Methicillin-Resistant Staphylococcus aureus , Sodium Bicarbonate , Teichoic Acids , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , beta-Lactams/pharmacology , Cefuroxime/pharmacology , Cell Wall/metabolism , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/genetics , Microbial Sensitivity Tests , Monobactams/pharmacology , Sodium Bicarbonate/pharmacology , Staphylococcus aureus/metabolism , Teichoic Acids/biosynthesis
14.
Comput Struct Biotechnol J ; 20: 5790-5812, 2022.
Article in English | MEDLINE | ID: mdl-36382179

ABSTRACT

The relevance of protein-glycan interactions in immunity has long been underestimated. Yet, the immune system possesses numerous classes of glycan-binding proteins, so-called lectins. Of specific interest is the group of myeloid C-type lectin receptors (CLRs) as they are mainly expressed by myeloid cells and play an important role in the initiation of an immune response. Myeloid CLRs represent a major group amongst pattern recognition receptors (PRRs), placing them at the center of the rapidly growing field of glycoimmunology. CLRs have evolved to encompass a wide range of structures and functions and to recognize a large number of glycans and many other ligands from different classes of biopolymers. This review aims at providing the reader with an overview of myeloid CLRs and selected ligands, while highlighting recent insights into CLR-ligand interactions. Subsequently, methodological approaches in CLR-ligand research will be presented. Finally, this review will discuss how CLR-ligand interactions culminate in immunological functions, how glycan mimicry favors immune escape by pathogens, and in which way immune responses can be affected by CLR-ligand interactions in the long term.

15.
J Environ Manage ; 320: 115941, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-36056500

ABSTRACT

Understanding the mechanism of public perception and behavior towards environmental goods provision is essential for effective sustainable governance. This paper studies how citizens' self-reported environmental knowledge affects their trust in public service providers and subsequently their decisions about accepting the provision of a pollution management facility in their neighborhood. Utilizing unique survey data on the siting of a facility for waste incineration in Guangzhou, China, we find that the public's perceived environmental knowledge damages their trust in the operator, which lowers their acceptance of the facility siting, while damage to their trust in the government is negligible. In addition, we find that citizens' preferences for the type of information disclosed and the channels used for disclosure can affect public trust and thus acceptance of the facility siting. Therefore, policy suggestions for urban planning for sustainability are that the urban planner and policy maker can mitigate the negative consequences of bounded environmental knowledge by ensuring there is appropriate information disclosure. This study broadens our understanding of public recognition and acceptance of environmental goods provision and provides practical suggestions for sustainable development.


Subject(s)
Incineration , Trust , China , Government , Humans
16.
Microbiol Spectr ; 10(3): e0141322, 2022 06 29.
Article in English | MEDLINE | ID: mdl-35647874

ABSTRACT

Bacterial cell division is a complex and highly regulated process requiring the coordination of many different proteins. Despite substantial work in model organisms, our understanding of the systems regulating cell division in noncanonical organisms, including critical human pathogens, is far from complete. One such organism is Staphylococcus aureus, a spherical bacterium that lacks known cell division regulatory proteins. Recent studies on GpsB, a protein conserved within the Firmicutes phylum, have provided insight into cell division regulation in S. aureus and other related organisms. It has been revealed that GpsB coordinates cell division and cell wall synthesis in multiple species. In S. aureus, we have previously shown that GpsB directly regulates FtsZ polymerization. In this study, using Bacillus subtilis as a tool, we isolated spontaneous suppressors that abrogate the lethality of S. aureus GpsB overproduction in B. subtilis. Through characterization, we identified several residues important for the function of GpsB. Furthermore, we discovered an additional role for GpsB in wall teichoic acid (WTA) biosynthesis in S. aureus. Specifically, we show that GpsB directly interacts with the WTA export protein TarG. We also identified a region in GpsB that is crucial for this interaction. Analysis of TarG localization in S. aureus suggests that WTA machinery is part of the divisome complex. Taken together, this research illustrates how GpsB performs an essential function in S. aureus by directly linking the tightly regulated cell cycle processes of cell division and WTA-mediated cell surface decoration. IMPORTANCE Cytokinesis in bacteria involves an intricate orchestration of several key cell division proteins and other factors involved in building a robust cell envelope. Presence of teichoic acids is a signature characteristic of the Gram-positive cell wall. By characterizing the role of Staphylococcus aureus GpsB, an essential cell division protein in this organism, we have uncovered an additional role for GpsB in wall teichoic acid (WTA) biosynthesis. We show that GpsB directly interacts with TarG of the WTA export complex. We also show that this function of GpsB may be conserved in other GpsB homologs as GpsB and the WTA exporter complex follow similar localization patterns. It has been suggested that WTA acts as a molecular signal to control the activity of autolytic enzymes, especially during the separation of conjoined daughter cells. Thus, our results reveal that GpsB, in addition to playing a role in cell division, may also help coordinate WTA biogenesis.


Subject(s)
Staphylococcal Infections , Teichoic Acids , Virulence Factors/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Cell Division , Cell Wall/metabolism , Humans , Staphylococcal Infections/microbiology , Staphylococcus aureus/metabolism , Teichoic Acids/metabolism
17.
Front Psychol ; 13: 866124, 2022.
Article in English | MEDLINE | ID: mdl-35592172

ABSTRACT

Artificial intelligence (AI) has become one of the core driving forces for the future development of the medical industry, but patients are skeptical about the use of AI in medical care. Based on the intergroup threat theory (ITT), this study verified that patients would regard AI as an external group, triggering the perceived threat of the external group, which results in avoidance behaviors in the treatment (experiment 1: n = 446) and diagnosis (experiment 2: n = 330) scenarios. The results show that despite AI can provide expert-level accuracy in medical care, patients are still more likely to rely on human doctors and experience more negative emotions as AI is more involved in medical care (experiment 1). Furthermore, patients pay more attention to threats at the individual level related to themselves, such as realistic threats related to privacy issues and symbolic threats related to the neglect of personal characteristics. In contrast, realistic threats and symbolic threats at the group level had less effect on patients in the medical scenario (experiment 2).

18.
Acta Psychol (Amst) ; 223: 103462, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35030363

ABSTRACT

The amount of money individuals were willing to accept (WTA) to discontinue using prominent Chinese social media platforms (WeChat/QQ), the willingness to pay (WTP) for using these platforms, as well as WTA/WTP disparities were investigated in between-groups and within-subjects design studies to examine their existence, size, and psychological correlates in the form of personality and social media use habits. Individuals were recruited at Chinese universities in three separate surveys. For between-groups investigations, four samples were investigated: WTA and WTP samples for investigations in the context of WeChat as well as WTA and WTP samples for QQ. For within-subjects investigations, individuals completed items on WTA and WTP for WeChat/QQ, the Big Five Inventory, time spent on WeChat/QQ, and the short Bergen Social Media Addiction Scale. Two samples providing data on WeChat and QQ, respectively, were investigated. Across study designs and for both WeChat and QQ we found evidence for high WTA and comparatively low WTP scores, thus, large WTA/WTP disparities. Individual differences in the disparities were negatively associated with Openness across social media platforms. The results reveal a generally low acceptance to pay for social media use, which is important against the background of discussions on monetary payment models. Moreover, a complex interplay between individual characteristics, characteristics of the service, and how and why the service is used seems to underly WTA and the WTA/WTP disparity. Finally, methodological implications of the present results for forthcoming studies assessing valuation (WTA, WTP) in the context of social media are discussed.


Subject(s)
Social Media , China , Humans , Patient Acceptance of Health Care , Personality
19.
Methods Mol Biol ; 2386: 263-288, 2022.
Article in English | MEDLINE | ID: mdl-34766276

ABSTRACT

Single-cell RNA sequencing (sc-RNAseq) has become a critical approach for the analysis of immune cell function and heterogeneity. So far, the immune cell isolation, based on surface marker expression predicted by the RNA expression profiles, is often limited by the poor correlation between transcript and protein expression patterns. To overcome these difficulties, novel single-cell multi-omic approaches based on the combined analysis of transcript and surface protein expression have been developed. One of the major benefits of these technologies is the possibility to use a high number of antibodies conjugated with oligonucleotide (AbOs) for the surface marker detection, thus overcoming the limit of using few surface markers as occurs in flow cytometry. Here we describe the BD Rhapsody single-cell analysis system protocol for 3' mRNA whole transcriptome analysis (WTA), combined with AbO- and Sample Tag library preparation.


Subject(s)
Single-Cell Analysis , Gene Expression Profiling , RNA , Sequence Analysis, RNA , Transcriptome
20.
Front Microbiol ; 12: 721426, 2021.
Article in English | MEDLINE | ID: mdl-34745029

ABSTRACT

Most isolated strains of Staphylococcus sciuri contain mecA1, the evolutionary origin of mecA, but are sensitive to ß-lactams (OS-MRSS, oxacillin-susceptible mecA1-positive S. sciuri). In order to improve the efficacy of antibiotic treatment, it is important to clarify whether the resistance of OS-MRSS to ß-lactams is an inducible phenotype. In this study, three OS-MRSS strains with oxacillin MIC = 1 µg/ml were isolated from 29 retail pork samples. The resistance of OS-MRSS to ß-lactams (MIC > 256 µg/ml) was found to be induced by oxacillin, and the induced resistance was observed to remain stable within a certain period of time. Interestingly, the induced ß-lactam resistance was not caused by mecA1, heterogeneous resistance, or any genetic mutation, but mainly due to increased wall teichoic acid (WTA) synthesis that thickened the cell wall. The induced strains also showed slower growth rate, as well as decreased adhesion ability and biofilm thickness. These phenotypes were found to be achieved through altered gene expression in associated pathways, such as the citrate cycle and pentose phosphate pathway. The results challenge the traditional antibiotic sensitivity test. In the presence of ß-lactam antibiotics, OS-MRSS that was initially sensitive to ß-lactams was observed to gradually develop ß-lactam resistance in several days. This often-neglected phenomenon in antibiotic sensitivity tests requires further research attention.

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