A novel synthetic synovial fluid model for investigating biofilm formation and antibiotic susceptibility in prosthetic joint infections.

Unlabelled: There is growing evidence that bacteria encountered in prosthetic joint infections (PJIs) form surface-attached biofilms on prostheses, as well as biofilm aggregates embedded in synovial fluid and tissues. However, models allowing the investigation of these biofilms and the assessment of their antimicrobial susceptibility in physiologically relevant conditions are currently lacking. To address this, we developed a synthetic synovial fluid (SSF2) model and validated this model by investigating growth, aggregate formation, and antimicrobial susceptibility using multiple PJI isolates belonging to various microorganisms.

Global challenges and microbial biofilms: Identification of priority questions in biofilm research, innovation and policy.

Priority question exercises are increasingly used to frame and set future research, innovation and development agendas. They can provide an important bridge between the discoveries, data and outputs generated by researchers, and the information required by policy makers and funders. Microbial biofilms present huge scientific, societal and economic opportunities and challenges.

Evaluation of antibiofilm agents for treatment of cystic fibrosis-related chronic rhinosinusitis.

Treatment of cystic fibrosis-related chronic rhinosinusitis should target sinonasal biofilms. NaHCO salts with/without xylitol have limited antibiofilm properties, whereas rhDNAse has not. Phage effectivity varies and depends on the phage and the combination with antibiotics.

Antibiofilm activity of species from the cystic fibrosis lung microbiota against .

It is increasingly recognized that interspecies interactions may modulate the pathogenicity of during chronic lung infections. Nevertheless, while the interaction between and pathogenic microorganisms co-infecting the lungs has been widely investigated, little is known about the influence of other members of the lung microbiota on the infection process. In this study, we focused on investigating the impact of species isolated from the sputum of people with cystic fibrosis (pwCF) on biofilm formation and virulence factor production by .

Carbon source competition within the wound microenvironment can significantly influence infection progression.

It is becoming increasingly apparent that commensal skin bacteria have an important role in wound healing and infection progression. However, the precise mechanisms underpinning many of these probiotic interactions remain to be fully uncovered. In this work, we demonstrate that the common skin commensal Cutibacterium acnes can limit the pathogenicity of the prevalent wound pathogen Pseudomonas aeruginosa in vivo.

Genome-scale model of predicts gene essentialities and reveals metabolic capabilities.

Cystic fibrosis (CF), an inherited genetic disorder caused by mutations in the cystic fibrosis transmembrane conductance regulator gene, results in sticky and thick mucosal fluids. This environment facilitates the colonization of various microorganisms, some of which can cause acute and chronic lung infections, while others may positively impact the disease. , an oral commensal, is relatively abundant in the lungs of CF patients.

Pooling isolates to address the diversity in antimicrobial susceptibility of in cystic fibrosis.

People with cystic fibrosis (pwCF) often suffer from chronic lung infections with . While antibiotics are still commonly used to treat infections, there is a high discordance between and antibiotic efficacy, which contributes to suboptimal antibiotic therapy. In the present study, we found that isolates from the same sputum sample had highly diverse antibiotic resistance profiles [based on the minimal inhibitory concentration (MIC)], which may explain the reported discrepancy between and antibiotic efficacy.

Effect of Poly(Vinyl Pyrrolidone) on Iodine Release from Acrylate-Endcapped Urethane-Based Poly(Ethylene Glycol) Hydrogels as Antibacterial Wound Dressing.

Infections are still a major cause of morbidity in burn wounds. Although silver has been used strongly in past centuries as an anti-bacterial, it can lead to allergic reactions, bacterial resistance, and delayed wound healing. Iodine-based antibacterials are becoming an interesting alternative.

Effect of malate on the activity of ciprofloxacin against in different and -like infection models.

The clinical significance of infections and the tolerance of this opportunistic pathogen to antibiotic therapy makes the development of novel antimicrobial strategies an urgent need. We previously found that D,L-malic acid potentiates the activity of ciprofloxacin against biofilms grown in a synthetic cystic fibrosis sputum medium by increasing metabolic activity and tricarboxylic acid cycle activity. This suggested a potential new strategy to improve antibiotic therapy in infections.

Biofilm antimicrobial susceptibility testing: where are we and where could we be going?

Our knowledge about the fundamental aspects of biofilm biology, including the mechanisms behind the reduced antimicrobial susceptibility of biofilms, has increased drastically over the last decades. However, this knowledge has so far not been translated into major changes in clinical practice. While the biofilm concept is increasingly on the radar of clinical microbiologists, physicians, and healthcare professionals in general, the standardized tools to study biofilms in the clinical microbiology laboratory are still lacking; one area in which this is particularly obvious is that of antimicrobial susceptibility testing (AST).

3D-printed wound dressings containing a fosmidomycin-derivative prevent biofilm formation.

causes a wide range of infections, including wound infections. Multidrug-resistant is a major healthcare concern and the development of novel treatments against these infections is needed. Fosmidomycin is a repurposed antimalarial drug targeting the non-mevalonate pathway, and several derivatives show activity toward .

Combining phages and antibiotic to enhance antibiofilm efficacy against an dual species wound biofilm.

Chronic wound management is extremely challenging because of the persistence of biofilm-forming pathogens, such as and , which are the prevailing bacterial species that co-infect chronic wounds. Phage therapy has gained an increased interest to treat biofilm-associated infections, namely when combined with antibiotics. Here, we tested the effect of gentamicin as a co-adjuvant of phages in a dual species-biofilm wound model formed on artificial dermis.

What's in a name? Characteristics of clinical biofilms.

In vitro biofilms are communities of microbes with unique features compared to individual cells. Biofilms are commonly characterized by physical traits like size, adhesion, and a matrix made of extracellular substances. They display distinct phenotypic features, such as metabolic activity and antibiotic tolerance.

A systematic review of the use of bacteriophages for in vitro biofilm control.

Bacteriophages (phages) are very promising biological agents for the prevention and control of bacterial biofilms. However, little is known about the parameters that can influence the efficacy of phages on biofilms. This systematic review provides a summary and analysis of the published data about the use of phages to control pre-formed biofilms in vitro, suggesting recommendations for future experiments in this area.

and evaluation of diethyldithiocarbamate with copper ions and its liposomal formulation for the treatment of and biofilms.

Surgical site infections (SSIs) are mainly caused by () and () biofilms. Biofilms are aggregates of bacteria embedded in a self-produced matrix that offers protection against antibiotics and promotes the spread of antibiotic-resistance in bacteria. Consequently, antibiotic treatment frequently fails, resulting in the need for alternative therapies.

The Small RNA NcS25 Regulates Biological Amine-Transporting Outer Membrane Porin BCAL3473 in Burkholderia cenocepacia.

Regulation of porin expression in bacteria is complex and often involves small-RNA regulators. Several small-RNA regulators have been described for Burkholderia cenocepacia, and this study aimed to characterize the biological role of the conserved small RNA NcS25 and its cognate target, outer membrane protein BCAL3473. The B.

High throughput determination of the biofilm prevention concentration for biofilms using a synthetic cystic fibrosis sputum medium.

The presence of biofilms in cystic fibrosis (CF) patients suffering from chronic lung infections contributes to the failure of antimicrobial therapy. Conventionally, the minimal inhibitory concentration (MIC) is determined to assess the antimicrobial susceptibility of a pathogen, however this parameter fails to predict success in treating biofilm-associated infections. In the present study we developed a high throughput method to determine the antimicrobial concentration required to prevent biofilm formation, using a synthetic cystic fibrosis sputum medium (SCFM2).

Adaptation of biofilms to tobramycin and the quorum sensing inhibitor C-30 during experimental evolution requires multiple genotypic and phenotypic changes.

In the present study we evaluated the fitness, antimicrobial susceptibility, metabolic activity, gene expression, production of virulence factors and virulence of experimentally evolved PAO1. These strains were previously evolved in the presence of tobramycin and the quorum sensing inhibitor furanone C-30 (C-30) and carried mutations in and . Compared to the wild-type (WT), the evolved strains show a different growth rate and different metabolic activity, suggesting they have an altered fitness.

Phenotypic Characterization and Heterogeneity among Modern Clinical Isolates of Acinetobacter baumannii.

Acinetobacter baumannii is an opportunistic pathogenic bacterium prioritized by WHO and CDC because of its increasing antibiotic resistance. Heterogeneity among strains represents the hallmark of A. baumannii bacteria.

Sebaceous immunobiology - skin homeostasis, pathophysiology, coordination of innate immunity and inflammatory response and disease associations.

This review presents several aspects of the innovative concept of sebaceous immunobiology, which summarizes the numerous activities of the sebaceous gland including its classical physiological and pathophysiological tasks, namely sebum production and the development of seborrhea and acne. Sebaceous lipids, which represent 90% of the skin surface lipids in adolescents and adults, are markedly involved in the skin barrier function and perifollicular and dermal innate immune processes, leading to inflammatory skin diseases. Innovative experimental techniques using stem cell and sebocyte models have clarified the roles of distinct stem cells in sebaceous gland physiology and sebocyte function control mechanisms.

Acyloxymethyl and alkoxycarbonyloxymethyl prodrugs of a fosmidomycin surrogate as antimalarial and antibacterial agents.

Fosmidomycin is a natural antibiotic with potent IspC (DXR, 1-deoxy-d-xylulose-5-phosphate reductoisomerase) inhibitory activity. This enzyme catalyzes the first committed step of the non-mevalonate isoprenoid biosynthesis pathway, which is essential in most bacteria, including A. baumanii and M.

New concepts in antimicrobial resistance in cystic fibrosis respiratory infections.

In this review, we summarize the main points that were raised and highlighted during the pre-conference meeting to the 17 European Cystic Fibrosis Society Basic Science Conference, held from 30 March to 2 April, 2022 in Albufeira, Portugal. Keynote lectures provided an update on the latest information regarding the phenomenon of antimicrobial resistance (AMR) in cystic fibrosis (CF). Traditional themes such as in vitro antibiotic susceptibility testing and its clinical value, AMR evolution in persistent Pseudomonas aeruginosa infection and the impact of biofilm on AMR were discussed.

Biofilm antimicrobial susceptibility through an experimental evolutionary lens.

Experimental evolution experiments in which bacterial populations are repeatedly exposed to an antimicrobial treatment, and examination of the genotype and phenotype of the resulting evolved bacteria, can help shed light on mechanisms behind reduced susceptibility. In this review we present an overview of why it is important to include biofilms in experimental evolution, which approaches are available to study experimental evolution in biofilms and what experimental evolution has taught us about tolerance and resistance in biofilms. Finally, we present an emerging consensus view on biofilm antimicrobial susceptibility supported by data obtained during experimental evolution studies.

Antibiofilm Activities of Borneol-Citral-Loaded Pickering Emulsions against Pseudomonas aeruginosa and Staphylococcus aureus in Physiologically Relevant Chronic Infection Models.

Phytochemicals are promising antibacterials for the development of novel antibiofilm drugs, but their antibiofilm activity in physiologically relevant model systems is poorly characterized. As the host microenvironment can interfere with the activity of the phytochemicals, mimicking the complex environment found in biofilm associated infections is essential to predict the clinical potential of novel phytochemical-based antimicrobials. In the present study, we examined the antibiofilm activity of borneol, citral, and combinations of both as well as their Pickering emulsions against Staphylococcus aureus and Pseudomonas aeruginosa in an -like synthetic cystic fibrosis medium (SCFM2) model, an wound model (consisting of an artificial dermis and blood components at physiological levels), and an Galleria mellonella model.

The combination of diethyldithiocarbamate and copper ions is active against and biofilms and .

and are associated with life-threatening infections. Despite the best medical care, these infections frequently occur due to antibiotic resistance and the formation of biofilms of these two bacteria (i.e.