Combinatorial RiPP biosynthesis for the generation of gene-encoded new-to-nature peptide antimicrobials

The excessive and inappropriate use of antibiotics has escalated antimicrobial resistance, driving the urgent need for novel antibiotics with innovative structures and modes of action. Non-ribosomal peptides (NRPs), such as the last-resort antibiotics daptomycin and polymyxin, exhibit potent antibacterial activity, but their significant side effects limit their application. Various endeavours have been made to create improved NRP analogues, but with limited success. In contrast, ribosomally synthesized and post-translationally modified peptides (RiPPs) are highly amenable to engineering. As RiPPs encompass much of the chemical diversity found in NRPs, they offer a new avenue for creating structural and functional NRP mimics via ribosomal pathways. In this thesis, we developed multiple novel RiPP combinatorial biosynthesis pathways that combine modifications from diverse RiPP enzymes into a single peptide, yielding such NRP mimics. We devised a chimeric leader that facilitates recognition for modification by three different RiPP modification enzymes, the epimerase OspD, the arginase OspR, and the lanthionine macrocyclase SyncM, resulting in the in vivo production of macrocyclic peptides containing D-amino acids and ornithines. Advancing further, sequences of a wide variety of NRP antibiotics were closely mimicked, successfully generating various NRP mimics with antibacterial activity against both Gram-negative and Gram-positive ESKAPE-pathogens. In addition, we established another hybrid pathway, introducing a β-amino acid and macrocycle in a single product by the ketoamide-installing splicease PlpYX, and SyncM, creating a structural mimic of the anti-cancer NRP aplidin. Overall, this work demonstrates the feasibility of generating gene-encoded NRP-emulating antimicrobial peptides through RiPP biosynthesis, offering promise in addressing antibiotic resistance

Combinatorial biosynthesis for the generation of new-to-nature peptide antimicrobials

Natural peptide products are a valuable source of important therapeutic agents, including antibiotics, antivirals and crop protection agents. Aided by an increased understanding of structure-activity relationships of these complex molecules and the biosynthetic machineries that produce them, it has become possible to re-engineer complete machineries and biosynthetic pathways to create novel products with improved pharmacological properties or modified structures to combat antimicrobial resistance. In this review, we will address the progress that has been made using non-ribosomally produced peptides and ribosomally synthesized and post-translationally modified peptides as scaffolds for designed biosynthetic pathways or combinatorial synthesis for the creation of novel peptide antimicrobials

Mental health professionals’ knowledge, skills and attitudes on domestic violence and abuse in the Netherlands:Cross-sectional study

Background Despite the high prevalence of domestic violence and abuse (DVA) among patients with psychiatric conditions, detection rates are low. Limited knowledge and skills on DVA in mental healthcare (MHC) professionals might contribute to poor identification.AimsTo assess the level of, and factors associated with, DVA knowledge and skills among MHC professionals. Method A total of 278 professionals in Dutch MHC institutions completed a survey assessing factual knowledge, perceived knowledge, perceived skills and attitudes about DVA. Results On average, low scores were reported for perceived skills and knowledge. MHC professionals in primary care scored higher than those working with individuals with severe mental illness (P<0.005). Levels of factual knowledge were higher; levels of attitudes moderate. Previous training was positively associated with skills (odds ratios (OR) = 3.0) and attitudes (OR = 2.7). Years of work was negatively associated with factual knowledge (OR = 0.97). Larger case-loads predicted higher scores on skills (OR = 2.1). Conclusions Training is needed, particularly for clinicians working with patients with severe mental illness

Experiencing discrimination mediates the relationship between victimization and social withdrawal in patients suffering from a severe mental illness:A cross-sectional study

Psychiatric patients are often victims of crime and discrimination and are often socially withdrawn. This has negative consequences for their health and recovery. We examined whether such discrimination mediates the association between victimization and social withdrawal, and whether these associations differ between men and women. We also determined the prevalence of social withdrawal and the discrimination experienced by patients suffering from a severe mental illness. This study is embedded in the Victimization in Psychiatric Patients study. Information on discrimination, social withdrawal and victimization was obtained using structured self-report questionnaires (N = 949). We reported the 12-month prevalence of these phenomena and used path analysis to estimate the direct path between personal and property victimization and social withdrawal, and the indirect path through the discrimination experienced. The impact of gender was assessed by testing interaction terms. Social withdrawal was reported by 20.6% (95%CI 18.1–23.2) of participants, and being discriminated against in the past 12 months by 75.3% (95%CI: 72.6–78.0%). While crime victimization had no direct effects on social withdrawal, personal crime victimization (B = 0.47; 95%CI 0.25-0.72; p < 0.001) and property crime victimization (B = 0.65; 95%CI 0.42-0.93; p < 0.001) had significant indirect effects on social withdrawal, which were mediated by the discrimination experienced. In men we found a direct negative effect of property crime on social withdrawal (B = -0.68; 95%CI: −1.21to −0.11, p = 0.014). We conclude that personal and property victimization, for both men and women, was associated with higher levels of social withdrawal, and this was fully mediated by the discrimination experienced

Assessing the Acceptability, Feasibility and Sustainability of an Intervention to Increase Detection of Domestic Violence and Abuse in Patients Suffering From Severe Mental Illness: A Qualitative Study

Rationale: Despite interventions to improve detection rates, domestic violence, and abuse (DVA) remains largely undetected by healthcare services. We therefore aimed to examine the acceptability, feasibility, and sustainability of an intervention aiming to improve DVA detection rates, which included a clear referral pathway (i.e., the BRAVE intervention) and to explore the acceptability and feasibility of DVA management and referrals in general, in the context of low detection rates. Methods: Qualitative study design with four focus groups of 16 community mental health (CMH) clinicians from both control and intervention arms. The focus groups discussed managing DVA in clinical practice and staff experiences with the BRAVE intervention in particular. Focus groups continued until saturation of the subject was reached. Interviews were analyzed using a thematic analysis approach. Results: DVA was seen to be highly relevant to mental healthcare but is also a very sensitive subject. Barriers in CMH professionals, institutions, and society meant CMH professionals often refrained from asking about DVA in patients. Barriers included communication difficulties between CMH professionals and DVA professionals, a fear of disrupting the therapeutic alliance with the patient, and a lack of appropriate services to help victims of DVA. Conclusion: The BRAVE intervention was acceptable but not feasible or sustainable. Personal, institutional, and public barriers make it not feasible for CMH professionals to detect DVA in mental healthcare. To increase the detection of DVA, professional standards should be combined with training, feedback sessions with peers and DVA counselors, and routine enquiry about DVA

Дослідження руху індексу Doing Business України

Background: Domestic Violence and Abuse (DVA) is associated with a range of psychosocial and mental health problems. Having a psychiatric illness increases likelihood of being a victim of DVA. Despite the evidence of a high risk for DVA and the serious effects of violent victimization in psychiatric patients, detection rates are low and responses are inadequate. The aim of the BRAVE (Better Reduction trough Assessment of Violence and Evaluation) study is to improve detection of and response to DVA in psychiatric patients. In this article, we present the protocol of the BRAVE study which follows the SPIRIT guidelines. Methods: The BRAVE study is a cluster randomized controlled trial. We will include 24 community mental health teams from Rotterdam and The Hague. Twelve teams will provide care as usual and 12 teams will receive the intervention. The intervention consists of 1) a knowledge and sk

The VR2 Epitope on the PorA P1.7-2,4 Protein Is the Major Target for the Immune Response Elicited by the Strain-Specific Group B Meningococcal Vaccine MeNZB

A protracted epidemic of group B meningococcal disease in New Zealand led to the testing of a strain-specific tailor-made vaccine, MeNZB. Immunogenicity levels achieved during age group trials enabled New Zealand's regulatory authority to grant licensure to deliver MeNZB to all individuals under age 20. During the trials target strains for serum bactericidal antibody measurements included the vaccine target strain NZ98/254 and two comparator epidemic-type strains (NZ94/167 and NZ02/09). In this study, 12 other strains differing variously from the vaccine strain by their capsular group, PorB type, and PorA variable region specificities, or PorA expression, were used as target strains. The PorA specificity of the serum bactericidal antibody responses to the vaccine was determined for 40 vaccinees. Sets of 10 pre- and postvaccination sera were chosen randomly from the young infant, older infant, toddler, and school-age group trials. Antibody recognition of linearized PorA proteins was also determined using immunoblotting. Across all age groups vaccine-induced serum bactericidal antibodies specifically targeted the VR2 P1.4 epitope of the PorA P1.7-2,4 protein irrespective of the PorB type and/or capsular type of the target strain. Deletion of amino acids within the VR2 epitope or replacement of the epitope through genetic exchange allowed strains variously to resist antibody-directed complement-mediated lysis and negated PorA-specific antibody recognition in immunoblots. The demonstration that the immunodominant antibody response was specifically for the VR2 P1.4 epitope of the PorA protein supports the public health decision to use a strain-specific vaccine for the control of New Zealand's epidemic of meningococcal disease

Emulating nonribosomal peptides with ribosomal biosynthetic strategies

Peptide natural products are important lead structures for human drugs and many nonribosomal peptides possess antibiotic activity. This makes them interesting targets for engineering approaches to generate peptide analogues with, for example, increased bioactivities. Nonribosomal peptides are produced by huge mega-enzyme complexes in an assembly-line like manner, and hence, these biosynthetic pathways are challenging to engineer. In the past decade, more and more structural features thought to be unique to nonribosomal peptides were found in ribosomally synthesised and posttranslationally modified peptides as well. These streamlined ribosomal pathways with modifying enzymes that are often promiscuous and with gene-encoded precursor proteins that can be modified easily, offer several advantages to produce designer peptides. This review aims to provide an overview of recent progress in this emerging research area by comparing structural features common to both nonribosomal and ribosomally synthesised and posttranslationally modified peptides in the first part and highlighting synthetic biology strategies for emulating nonribosomal peptides by ribosomal pathway engineering in the second part.ISSN:2633-067

Prevalence of adult sexual abuse in men with mental illness: Bayesian meta-analysis

Background Sexual abuse is a broad category of traumatic experiences that includes rape and any unwanted sexual contact with a body part or foreign object, whether penetrative, oral or otherwise. Although patients with mental illness have a higher risk of becoming victims of sexual abuse in adulthood, few studies investigate the proportion of male victims in this population. Their underrepresentation in research is a barrier to understanding the negative outcomes associated with sexual abuse in men. Aims We estimated the prevalence of recent (past year) and adulthood sexual abuse perpetrated by any perpetrator and separately by intimate partners in males diagnosed with a mental illness. Method To model the prevalences and heterogeneity arising from reports, we used Bayesian multilevel models. Prevalences were estimated for mixed-diagnosis, substance misuse, intellectual disability and post-traumatic stress disorder samples, and studies reporting specifically on intimate partner violence. This review was registered through PROSPERO (CRD42020169299) Results Estimated adult sexual abuse was 5.3% (95% Credibility Interval 1.6-12.8%) for past-year abuse and 14.1% (95% Credibility Interval 7.3-22.4%) for abuse in adulthood. There was considerable heterogeneity of prevalence between studies and diagnosis groups. Conclusions Our analyses show that the prevalence of sexual abuse of males diagnosed with a mental illness was much higher than for men in the general population. This has important implications regarding the proportion of undetected or untreated sexually abused men in clinical practice