Search Results (6)

The rise in antimicrobial resistance represents a significant challenge to global health. The reason partially lies in an inappropriate use of conventional antibiotics and the subsequent rapid spread of multidrug-resistant pathogen strains. This emergency requires an urgent search for conceptually new antimicrobial agents. A viable alternative to conventional antibiotics is antimicrobial peptides (AMPs), which are ribosomally synthesized molecules with considerable potential as next-generation anti-infectious therapeutics. Previously, we have reported on the β-hairpin peptide Ap9, an analog of abarenicin from the marine polychaeta Abarenicola pacifica, with potent activity against key Gram-negative pathogens. Here, it is shown that Ap9 acts in a manner resembling polymyxin B, namely via interaction with lipopolysaccharide (LPS), and retains its activity against polymyxin-resistant isolates without observed cross-resistance, and causes insignificant damage in cytoplasmic membrane at bactericidal concentrations. NMR spectroscopy reveals that LPS binding induces a conformational rearrangement of Ap9, its dimer formation, and local structural remodeling of the peptide region (residues 8–12) into 3₁₀-helix. Bacterial resistance to Ap9 was found to be relatively low with a reduced susceptibility associated with infrequent genetic alterations, such as the mutation in lptD or the deletion in mlaA. Furthermore, Ap9 demonstrates a favorable tolerability, a wider therapeutic window than that of polymyxin B, and a sufficiently long half-life through the systemic use, as well as in vivo efficacy in murine models of Gram-negative infections, including sepsis caused by the mcr-1-harboring Escherichia coli strain. The obtained results point to Ap9 as a promising candidate for further preclinical studies aimed at development of an alternative to polymyxins. Full article

Rising levels of antibiotic-resistant bacteria have led to increasing interest in the use of phage therapy as an alternative treatment. While phage therapy is conceptually simple, and numerous semi-anecdotal data suggest that it could be effective if properly managed, there have been only a few randomized, double-blind clinical trials of phage therapy so far. These trials unequivocally showed that phage therapy is safe, but there is still a paucity of data on its efficacy for managing various bacterial infections. One common response to this situation is that there is a mismatch between the regulations that govern the testing of new drugs, that is, chemical agents, and biological agents like bacteriophages. Another response has been to sidestep clinical trial testing and to use phages to treat infected patients on an individual basis, sometimes called the magistral phage approach. In this paper, we argue that regulations are not the true barrier to approval of phage therapy as drugs but rather it is the lack of efficacy data. There is no one reason behind the failures of recent clinical trials. Instead, these demonstrate the complexity of implementing a therapy where both the treatment and disease are living entities interacting within another living entity, the patient. Phage banks can have an impact by monitoring these complexities during phage therapy. Importantly, phage therapy clinical trials are continuing under existing regulatory frameworks and with products manufactured under GMP (Good Manufacturing Practices). Full article

Biofilms as living microorganism communities are found anywhere, and for the healthcare sector, these constitute a threat and allied mechanism for health-associated or nosocomial infections. This review states the basis of biofilms and their formation. It focuses on their relevance for the biomedical sector, generalities, and the major advances in modified or new synthesized materials to prevent or control biofilm formation in biomedicine. Biofilm is conceptualized as an aggregate of cells highly communicated in an extracellular matrix, which the formation obeys to molecular and genetic basis. The biofilm offers protection to microorganisms from unfavorable environmental conditions. The most frequent genera of microorganisms forming biofilms and reported in infections are Staphylococcus spp., Escherichia spp., and Candida spp. in implants, heart valves, catheters, medical devices, and prostheses. During the last decade, biofilms have been most commonly related to health-associated infections and deaths in Europe, the United States, and Mexico. Smart, functional polymers are materials capable of responding to diverse stimuli. These represent a strategy to fight against biofilms through the modification or synthesis of new materials. Polypropylene and poly-N-isopropyl acrylamide were used enough in the literature analysis performed. Even smart polymers serve as delivery systems for other substances, such as antibiotics, for biofilm control. Full article

Background: Urinary tract infections (UTIs) are a common and significant problem for patients, clinicians, and healthcare services. Recurrent UTIs (rUTIs) are common, with a 3% prevalence in the UK. Although acute UTIs have a significant negative impact on the lives of patients, evidence of the impact of rUTIs is limited. To enhance shared decision-making around rUTI management, it is important to understand both the patients’ and healthcare professionals’ (HCPs’) perspectives. The objective of this qualitative evidence synthesis is to understand patients’ and HCPs’ experiences and views in the management of rUTIs. Methods: A qualitative evidence synthesis (QES) was performed that included primary qualitative studies involving patients with rUTIs or primary care HCPs who manage patients with rUTIs, up to June 2022. The following databases were searched: MEDLINE, Embase, CINAHL, PsycInfo, ASSIA, Web of Science, Cochrane Database of Systematic Reviews, Epistemonikos, Cochrane Central Registry of Controlled Trials, OpenGrey, and the Health Management Information Consortium (HMIC). The QES was prospectively registered on PROSPERO (CRD42022295662). Reciprocal translation was conducted and developed into a line of argument synthesis. We appraised the confidence in our review findings by using GRADE-CERQual. Results: Twelve studies were included in the final review; ten of those included patients, and three included HCPs (one study included both). Our review demonstrates that women with rUTIs have a unique experience, but it is generally of a chronic condition with significant impacts on numerous aspects of their lives. Antibiotics can be “transformative”, but patients have serious concerns about their use and feel non-antibiotic options need further research and discussion. HCPs share similar views about the impacts of rUTIs and concerns about antibiotic use and find the management of rUTIs to be complex and challenging. Based on our GRADE-CERQual assessment of the review findings, we have moderate confidence in those related to patients and low confidence in those related to HCPs. New conceptual models for both patients and HCPs are presented. Conclusions: This review has significant clinical implications. Patients require information on antibiotic alternative acute and preventative treatments for rUTIs, and this is not currently being addressed. There are communication gaps around the impact of rUTIs on patients, their perceived expectation for antibiotics, and the reasons for treatment failure. Further development of current clinical guidance and a patient decision aid would help address these issues. Full article

As a result of antibiotic overuse, bacterial antibiotic resistance has become a severe threat to worldwide public health. The development of more effective antimicrobial therapies and alternative antibiotic strategies is urgently required. The role played by bacterial membrane vesicles (BMVs) in antibiotic resistance has become a current focus of research. BMVs are nanoparticles derived from the membrane components of Gram-negative and Gram-positive bacteria and contain diverse components originating from the cell envelope and cytoplasm. Antibiotic stress stimulates the secretion of BMVs. BMVs promote and mediate antibiotic resistance by multiple mechanisms. BMVs have been investigated as conceptually new antibiotics and drug-delivery vehicles. In this article, we outline the research related to BMVs and antibiotic resistance as a reference for the intentional use of BMVs to combat antibiotic resistance. Full article

Most ribosomal antibiotics obstruct distinct ribosomal functions. In selected cases, in addition to paralyzing vital ribosomal tasks, some ribosomal antibiotics are involved in cellular regulation. Owing to the global rapid increase in the appearance of multi-drug resistance in pathogenic bacterial strains, and to the extremely slow progress in developing new antibiotics worldwide, it seems that, in addition to the traditional attempts at improving current antibiotics and the intensive screening for additional natural compounds, this field should undergo substantial conceptual revision. Here, we highlight several contemporary issues, including challenging the common preference of broad-range antibiotics; the marginal attention to alterations in the microbiome population resulting from antibiotics usage, and the insufficient awareness of ecological and environmental aspects of antibiotics usage. We also highlight recent advances in the identification of species-specific structural motifs that may be exploited for the design and the creation of novel, environmental friendly, degradable, antibiotic types, with a better distinction between pathogens and useful bacterial species in the microbiome. Thus, these studies are leading towards the design of “pathogen-specific antibiotics,” in contrast to the current preference of broad range antibiotics, partially because it requires significant efforts in speeding up the discovery of the unique species motifs as well as the clinical pathogen identification. Full article