Biocides as drivers of antibiotic resistance: A critical review of environmental implications and public health risks

The widespread and indiscriminate use of biocides poses significant threats to global health, socioeconomic development, and environmental sustainability by accelerating antibiotic resistance. Bacterial resistance development is highly complex and influenced significantly by environmental factors. Increased biocide usage in households, agriculture, livestock farming, industrial settings, and hospitals produces persistent chemical residues that pollute soil and aquatic environments. Such contaminants contribute to the selection and proliferation of resistant bacteria and antimicrobial resistance genes (ARGs), facilitating their dissemination among humans, animals, and ecosystems. In this review, we conduct a critical assessment of four significant issues pertaining to this topic. Specifically, (i) the role of biocides in exerting selective pressure within the environmental resistome, thereby promoting the proliferation of resistant microbial populations and contributing to the global spread of antimicrobial resistance genes (ARGs); (ii) the role of biocides in triggering transient phenotypic adaptations in bacteria, including efflux pump overexpression, membrane alterations, and reduced porin expression, which often result in cross-resistance to multiple antibiotics; (iii) the capacity of biocides to disrupt bacteria and make the genetic content accessible, releasing DNA into the environment that remains intact under certain conditions, facilitating horizontal gene transfer and the spread of resistance determinants; (iv) the capacity of biocides to disrupt bacterial cells, releasing intact DNA into the environment and enhancing horizontal gene transfer of resistance determinants; and (iv) the selective interactions between biocides and bacterial biofilms in the environment, strengthening biofilm cohesion, inducing resistance mechanisms, and creating reservoirs for resistant microorganisms and ARG dissemination. Collectively, this review highlights the critical environmental and public health implications of biocide use, emphasizing an urgent need for strategic interventions to mitigate their role in antibiotic resistance proliferation.

Inhibition of Clinical Multidrug-Resistant Pseudomonas aeruginosa Biofilms by Cinnamaldehyde and Eugenol From Essential Oils: In Vitro and In Silico Analysis

Pseudomonas aeruginosa causes nosocomial infections and chronic diseases. Cinnamomum cassia and Syzygium aromaticum are used natural antimicrobials. Essential oil (EO) from C. cassia (CCEO) and S. aromaticum (CEO) was characterized using GC-MS analysis. Eugenol (82.31%), eugenol acetate (10.57%), and β-caryophyllene (3.41%) were major constituents in CEO while cinnamaldehyde (88.18%), cinnamyl acetate (2.85%) and 2-methoxy cinnamaldehyde (1.77%) were main components in CCEO. The EOs and major constituents exhibited good antimicrobial activity against clinical strains of P. aeruginosa. Cinnamaldehyde exhibited the best antimicrobial effect with minimal inhibitory concentration (MIC) as low as 0.031% ± 0.07% (v/v) and inhibition zones reaching 30 ± 0.5 mm diameter. Test samples showed antibiofilm activities against two culture types and seven clinical strains of P. aeruginosa at concentrations of 2MIC to MIC/4. CCEO and its major constituent cinnamaldehyde were more active, compared to CEO and its major constituent eugenol. Scanning electron microscopy images showed untreated colonies with well-developed biofilms while there was significant reduction of biofilms with distorted architecture and cell shrinkage upon treatment with test samples. In silico studies indicated great interactions between the major compounds, eugenol and cinnamaldehyde, with the receptor proteins of P. aeruginosa revealed by negative binding energies. Eugenol and cinnamaldehyde exhibited appreciable druglikeness.

Antibiotic conjugates: Using molecular Trojan Horses to overcome drug resistance

Antimicrobial resistance (AMR) has become a global health crisis due to the rapid emergence of multi-drug-resistant bacteria. The paucity of novel antibiotics in the clinical pipeline has exacerbated this issue, thereby warranting the development of new antibacterial therapies. The 'Trojan Horse' strategy entails conjugating antibiotics with bioactive components that not only facilitate the entry of antibiotic molecules into bacterial cells by circumventing the membrane barriers, but also augment the effects of conventional antibiotics against recalcitrant pathogens. These Trojan Horse elements can also serve as a promising tool for repurposing drugs with hitherto unexamined antimicrobial activity, or drugs with limited clinical utility due to considerable toxic side effects. In this review, we have discussed the current state of research on antibiotic conjugates with monoclonal antibodies (mAbs), antimicrobial peptides (AMPs) and the iron-chelating siderophores. The rationale and mechanisms of different antibiotic conjugates have been summarized, and the preclinical and clinical evidence pertaining to the activity of these conjugates against drug-resistant pathogens have been reviewed. Furthermore, the challenges associated with the clinical translation of these novel antimicrobials, and the future research directions have also been discussed. While antibiotic conjugates offer an attractive alternative to conventional antimicrobials, there are several obstacles to their clinical translation. A greater understanding of the mechanisms underlying AMR, and continuing advances in genetic engineering, synthetic biology, and bioinformatics will be crucial in designing more selective, potent, and safe antibiotic conjugates for tackling multi-drug resistant (MDR) infections.

Green Synthesis of Zinc Oxide Nanoparticles Including Rosehip (Rosa canina L.) Seed Extract: Evaluation of Its Characterization and Bioactivity Properties

The use of bioactive compounds in plants as reducing, stabilizing, and capping agents in nanoparticle manufacturing is an exceptionally eco-friendly approach. This work used rosehip seed extract, acquired by automatic solvent extraction, in the microwave-assisted green production of zinc oxide nanoparticles (ZnO NPs). The total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity of the extracted materials and nanoparticles (NPs) were assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. The ideal synthesis parameters were established as 25 mL of extract, pH 12, 360 W of microwave power, and a metal salt concentration of 0.05 M for a duration of 7 min. The characterization of the ZnO NPs synthesized under these conditions was performed using x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy with energy-dispersive x-ray analysis (SEM-EDX), dynamic light scattering (DLS), zeta potential measurements, and UV-Vis spectrophotometry. High-purity, nano-sized, antioxidant ZnO NPs were manufactured using an ecologically friendly, sustainable, and ecological technique.

Harmonizing time with survival: Circadian rhythm and autophagy in plants

BACKGROUND

Circadian rhythm (CR) is a self-sustaining biological oscillation that synchronizes physiological processes with the Earth's 24-h light-dark cycle. In plants, it regulates crucial physiological functions. Autophagy, a conserved degradation mechanism, maintains cellular homeostasis by recycling damaged organelles and proteins. Emerging evidence suggests an interplay between CRs and autophagy, optimizing plant survival and productivity.

SCOPE

This review explores the molecular mechanisms underlying CR and autophagy, highlighting their roles in growth and stress adaptation. It further examines how circadian clock components regulate autophagy-related genes (ATGs) in response to external cues.

MAJOR CONCLUSIONS

CR fine-tune autophagy by temporally regulating ATG gene expression. Key transcription factors, including TOC1 and LUX, modulate autophagic activity, ensuring energy conservation. Autophagy reciprocally influences circadian signaling, adjusting metabolic balance under stress.

GENERAL SIGNIFICANCE

Despite extensive research on circadian regulation, a comprehensive understanding of how core clock components orchestrate ATG gene expression remains lacking. Understanding the crosstalk between CR and autophagy provides insights into plant resilience and productivity, potentially informing crop improvement strategies that enhance stress tolerance and resource efficiency. This review aims to bridge this gap by summarizing recent insights and proposing future research directions.

Correlation Analysis Between Physical-Chemical and Biological Conditions in the River and the Incidence of Diseases in the City of Piracicaba, Brazil

The Piracicaba River basin, in the State of São Paulo, Brazil, covers approximately 12,400 km2 and plays a crucial economic role in São Paulo's agribusiness corridor. However, it faces recurrent episodes of pollution, impacting water quality and public health, especially in urban areas exposed to contamination. Despite this, few studies have investigated the ecological and epidemiological consequences of this environmental degradation. Therefore, this study analyzed the correlation between physicochemical and biological variables of the Piracicaba River and the incidence of diseases in the city of Piracicaba between January 2019 and September 2024. Data on hospital admissions for respiratory, neurological, and liver symptoms were used, as well as environmental and water quality information, such as dissolved oxygen, turbidity, conductivity, and the presence of cyanobacteria, obtained from public databases. The results showed seasonal patterns and long-term trends, highlighting the health risks associated with the river's pollution. Parameters such as phosphorus, pH, cyanobacteria concentration and climatic factors (temperature and humidity) showed an influence on the occurrence of respiratory, digestive, and neurological diseases. The study reinforces the need for continuous monitoring of water quality and public policies to mitigate impacts on the population's health.

Phospholipids and peroxisomes in ferroptosis: the therapeutic target of acupuncture regulating vascular cognitive impairment and dementia

Ferroptosis, since its conceptualization in 2012, has witnessed an exponential growth in research interest over recent years. It is regulated by various cellular metabolic pathways during chronic cerebral ischemia and hypoxia, including reactive oxygen species (ROS) generation, iron accumulation, abnormalities in glutathione metabolism, and disruptions in lipid and glucose metabolism. With the deepening and widespread research, ferroptosis has emerged as a critical pathway in the pathogenesis of vascular cognitive impairment and dementia (VCID). This unique cell death pathway caused by iron-dependent phospholipid peroxidation is strongly related to VICD. We examine the impact of phospholipid composition on neuronal susceptibility to ferroptosis, with a particular focus on the critical role of polyunsaturated fatty acids (PUFAs) in this process. Intriguingly, peroxisomes, as key regulators of lipid metabolism and oxidative stress, influence the susceptibility of neuronal cells to ferroptosis through the synthesis of plasmalogens and other lipid species. In this Review, we provide a critical analysis of the current molecular mechanisms and regulatory networks of acupuncture for ferroptosis, the potential functions of acupuncture in peroxisomal functions and phospholipid metabolism, and its neuroprotective effects in VCID, together with a potential for therapeutic targeting. As such, this highlights the theoretical basis for the application of acupuncture in VCID through multi-target regulation of ferroptosis. This review underscores the potential of acupuncture as a non-pharmacological therapeutic approach in VCID, offering new insights into its role in modulating ferroptosis and associated metabolic pathways for neuroprotection.

A review of cell death pathways in hemorrhagic stroke

Hemorrhagic stroke is a debilitating neurological disease, affecting millions worldwide. Characterized by bleeding in the brain, it is caused by a breakdown of the blood-brain barrier (BBB) and causes damage through the presence of iron in the brain, immune activation and increased intracranial pressure. The goal of this mini-review is to explore the signaling pathways that lead to cell death that are a part of disease progression in hemorrhagic stroke. This mini-review will highlight clinical observations and data, while also incorporating findings using preclinical disease models. There are important roles for apoptosis, necroptosis, necrosis, autophagy, ferroptosis, and pyroptosis in hemorrhagic stroke. Recent work has highlighted the interplay between these phenomena, providing key regulators as potential therapeutic targets, including reactive oxygen species, iron metabolism, and caspases. Therapeutic strategies that can delay or counteract the cytotoxic effects of hemorrhage can improve clinical outcomes in hemorrhagic stroke patients.

Antimicrobial peptides: evolving soldiers in the battle against drug-resistant superbugs

The discovery of antibiotics was one of the greatest achievements in human history, however, antibiotic resistance evolved no later than the introduction of antibiotics. The rapid evolution of antibiotic-resistant pathogens soon became frightening and remained a global healthcare threat. There is an urgent need to have new alternatives or new strategies to combat the multi-drug resistant superbugs such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), carbapenem-resistant Pseudomonas aeruginosa (CR-PA), extended-spectrum β-lactamases (ESBL) bearing multidrug-resistant Acinetobacter baumannii (MDR-AB), Escherichia coli (E. coli), and Klebsiella pneumoniae (K. pneumoniae). Antimicrobial peptides (AMPs) have been considered promising agents equipped with unique mechanisms of action along with several other benefits to fight the battle against drug-resistant superbugs. Overall, the current review summarizes the mechanisms of drug-resistant development, the mechanism of action adopted by AMPs to combat drug-resistant pathogens, and the immunomodulatory properties of AMPs. Additionally, we have also reviewed the synergistic potential of AMPs with conventional antibiotics along with the associated challenges and limitations of AMPs in the way of pharmacological development for therapeutic applications in clinical settings.

Cefiderocol activity against planktonic and biofilm forms of β-lactamase-producing pseudomonas aeruginosa from people with cystic fibrosis

OBJECTIVES

Chronic Pseudomonas aeruginosa infections are a leading cause of acute pulmonary exacerbations in people with cystic fibrosis (pwCF). Intrinsic antibiotic resistance and biofilm formation complicate treatment. This study investigates the genomic diversity and cefiderocol efficacy against planktonic and biofilm-associated forms of P. aeruginosa isolates from pwCF.

METHODS

Eight P. aeruginosa clinical isolates and three laboratory strains underwent whole genome sequencing (WGS). Biofilm formation was assessed through biomass, cell count, metabolic activity, and extracellular DNA (eDNA). The minimum bactericidal concentration (MBC90) and biofilm eradication concentration (MBEC90) were also determined.

RESULTS

WGS revealed significant genomic diversity, identifying ten distinct sequence types (STs). Antibiotic susceptibility testing (AST) showed that 10/11 strains were susceptible to cefiderocol, with one isolate (MPA9) displaying resistance linked to the blaOXA486 gene. Adding the β-lactamase inhibitor avibactam (AVI) restored susceptibility in this resistant strain. Although iron metabolism genes were highly conserved across isolates, MPA9 lacked the fpvA iron receptor, potentially contributing to cefiderocol resistance. Biofilm formation significantly increased tolerance to cefiderocol, with an 8-fold rise in MBEC90 compared to MBC90.

CONCLUSION

These findings highlight the genomic diversity and adaptive potential of P. aeruginosa in pwCF. Cefiderocol shows promise against planktonic and biofilm-associated P. aeruginosa, and combining it with AVI may counteract β-lactamase-mediated resistance.

A Water-Soluble Aggregation-Induced Emission Photosensitizer with Intrinsic Antibacterial Activity as an Antiplanktonic and Antibiofilm Therapeutic Agent

Photosensitizers (PSs) with aggregation-induced emission (AIE) properties have gained popularity for treating bacterial infections. However, most AIE PSs have a poor water solubility and low selectivity, limiting their applications in biological systems. Herein, we report a water-soluble and bacteria-targeting AIE PS that exhibits minimum cytotoxicity toward human cells with and without light irradiation. Acting as a narrow-spectrum antibacterial agent without light irradiation, TPA-1 eradicates planktonic Staphylococcus aureus and inhibits biofilm formation by targeting the S. aureus membrane, inhibiting the supercoiling activity of S. aureus DNA gyrase, and causing the downregulation of multiple essential proteins. Upon light irradiation, TPA-1 generates reactive oxygen species (ROS) that cause membrane damage, resulting in excellent antiplanktonic and antibiofilm activities against S. aureus and Pseudomonas aeruginosa, significantly reducing the number of viable bacteria in biofilms and promoting wound healing in vivo.

A bibliometric analysis of programmed cell death in oral cancer literature: research patterns and emerging trends (2000-2024)

BACKGROUND

Programmed cell death (PCD) plays a crucial role in oral cancer pathogenesis and treatment. However, a comprehensive bibliometric analysis of the global research landscape in this field has not been conducted. This study aims to analyze the evolution and current trends of PCD research in oral cancer from 2000 to 2024.

METHODS

Publications were retrieved from the Web of Science Core Collection database using relevant keywords related to oral cancer and PCD. VOSviewer 1.6.20 and CiteSpace 6.1R6 software were employed to conduct bibliometric analysis, including publication trends, citation analysis, co-authorship networks, keyword co-occurrence, and research hotspots. The time span was set from January 2000 to December 2024.

RESULTS

A total of 963 publications were identified and analyzed. The annual publication output showed a steady increase, with a significant growth rate after 2010, dividing the study period into three distinct phases. The most productive countries were China (58.42%), South Korea (12.27%), and Japan (10.04%), with China Medical University and Kaohsiung Medical University being the leading institutions. Research hotspots evolved from traditional apoptosis studies to emerging forms of PCD such as autophagy, ferroptosis, and pyroptosis. Keyword analysis revealed three major research clusters: basic molecular mechanisms (centered around ROS and oxidative stress), clinical aspects (including prognosis and cell proliferation), and cell death pathways. Citation burst analysis identified emerging trends in targeting multiple PCD pathways simultaneously for oral cancer therapy, with special focus on treatment resistance and survival.

CONCLUSION

This bibliometric analysis provides a comprehensive overview of global research trends in PCD and oral cancer over the past two decades. The findings highlight the shift from basic mechanistic studies focusing on apoptosis to more diverse PCD pathways and translational research. Emerging research directions include the exploration of synergistic mechanisms among multiple PCD pathways, development of AI-based personalized treatment plans, investigation of microenvironment regulation of PCD, and application of novel drug delivery systems. These trends demonstrate the field's evolution toward more integrated, personalized approaches in oral cancer treatment. This study offers valuable insights for researchers and funding agencies to identify research gaps and potential collaboration opportunities in this rapidly developing field.

Deciphering the Dilemma of Community Behavior Promotion and Inhibition by Cationic Bactericide-coated Nanoparticles in Gram-Negative Bacteria

Cationic bactericidal-coated gold nanoparticles are known to effectively prevent Gram-negative bacterial initial adhesion and community behavior development by strongly binding to bacterial surfaces and disrupting the cell membranes. However, such nanoparticles have been recently shown to unintentionally promote community behavior in Gram-negative bacteria because of the bacterial stress response. To find whether these contradictory findings are due to emerging stress response or poorly understood nanoparticle interactions of Gram-negative bacteria, in this work, we treated high population curli-producing Gram-negative Escherichia coli with cationic antibiotic/antiseptic-coated gold nanoparticles and followed the consequences in details using a variety of physical methods and controls. Parallelly, we employed standard biological assays commonly used to detect community behavior in bacteria. Biological assays yielded contradictory results some inferring promotion while others inferring inhibition. However, physical methods revealed that promotion and inhibition observations resulted from physical interactions without any bacterial response being involved. Using physical methods, we further demonstrated that macromolecules of cationic antibiotics and antiseptics exhibit similar consequences as nanoparticles, independent of inhibitory concentration. Overall, the results emphasize the need to consider physical interactions, rather than relying solely on standard biological assays, when evaluating the inhibition or promotion of community behavior by cationic antibiotic/antiseptic-coated nanoparticles or free cationic antibiotics/antiseptics against Gram-negative bacteria.

Insights into the mechanisms of apoptosis and pathogenesis in enterovirus 71 infections: A review

This study examines the intricate interactions between enterovirus 71 (EV71) and various programmed cell death pathways, specifically apoptosis, necroptosis, and pyroptosis, which collectively shape the pathogenesis and severity of EV71 infections. Primarily affecting children under 5 years of age, EV71 is a leading cause of hand, foot, and mouth disease and has been linked to severe neurological and systemic complications. This paper highlights how EV71 leverages distinct cell death mechanisms to enhance viral replication and amplify disease pathology. Apoptosis, for example, may restrict viral dissemination by systematically eliminating infected cells; however, EV71's activation of necroptosis and pyroptosis induces robust inflammatory responses, potentially resulting in extensive tissue damage and adverse health outcomes. Additionally, this study also summarizes recent advancements in the field, with an emphasis on experimental studies and clinical trials focused on vaccine and antiviral therapy development. Despite substantial progress, challenges persist, notably in achieving reliable vaccine efficacy and formulating safe treatment options specifically for pediatric populations. Moving forward, the review suggests that future research should delve further into understanding EV71-related complications, developing broad-spectrum antiviral agents, and investigating host genetic factors that may influence disease progression and outcomes. Ultimately, this research is essential for the development of targeted interventions capable of reducing severe symptoms without compromising the immune response, underscoring the importance of these efforts for public health and the management of infectious diseases.

Neuroprotective role of morin hydrate on 3-nitropropionic acid-elicited huntington's disease: in vivo investigation of RIPK1/RIPK3/MLKL necroptosis signaling pathway

BACKGROUND

Huntington's disease (HD) is a rare dominantly inheritable autosomal neurodegenerative disease with unclear pathophysiological pathways. In neurodegenerative disorders, including HD, necroptosis plays a significant role in neuronal death. Morin hydrate (MH), a natural bioactive flavonoid, has various pharmacological properties via orchestrating neuroinflammation, apoptosis, and necroptosis. Up to now, there is no extant data on the impact of MH on the necroptotic pathway in HD.

AIM

This research aimed to scrutinize the effect of MH on neurodegeneration initiated by 3-nitropropionic acid (3-NP) administration in rats via modulating necroptosis and apoptosis signaling pathways and compare it with necrosulfonamide (NSA) as a necroptosis inhibitor.

METHODS

HD was triggered in male wistar rats by intraperitoneal injection of 3-NP (10 mg/kg/day) for 14 days. Intraperitoneal injection of MH (20 mg/kg/day, i.p.) or NSA (1.65 mg/kg/day, i.p.) an hour prior to 3-NP administration for 14 days. At the end of study, rats were weighed, and their locomotor activity was assessed via grip strength and open field tests. Striata of rats were investigated histologically and immunohistochemically by evaluation the expression levels of glial fibrillary acidic protein (GFAP). Striatal tumor necrosis factor-alpha (TNF-α), caspase 3, and 8 levels were quantified through the ELISA technique, while striatal expression of necroptosis-associated proteins; phosphorylated form of receptor interacting protein kinase 1/3(p-RIPK1, p-RIPK3) and phosphorylated form of mixed lineage kinase domain-like protein (p-MLKL) were assessed by the Western blot technique. Striatal succinate dehydrogenase (SDH) activity was assayed colorimetrically. Finally, gene enrichment analysis using ShinyGO was employed.

RESULTS

MH and NSA significantly mitigated body weight loss and ameliorated locomotor deterioration, besides reversing histological abnormalities in the striatum of rats. Intriguingly, MH exerted similar effects on specific biomarkers and molecular signals as NSA. MH and NSA inhibited neuroinflammation, apoptosis, and necroptosis by significantly decreasing the striatal (TNF-α), caspase 3, and necroptosis-associated proteins (P-RIPK1, P-RIPK3, and P-MLKL) levels. Besides, MH and NSA also decreased striatal GFAP and increased SDH activity. Gene enrichment analysis revealed a significant interaction between genes. Together, MH exerts a neuroprotective action on 3-NP-elicited HD rats via reducing neuroinflammation, apoptosis, and necroptosis. This study highlights MH as a potential protection against HD, calling for further research to confirm its neuroprotective effects.

Mycobacterium tuberculosis Sulfate Ester Dioxygenase Rv3406 Is Able to Inactivate the RCB18350 Compound

Among the critical priority pathogens listed by the World Health Organization, Mycobacterium tuberculosis strains resistant to rifampicin present a significant global threat. Consequently, the study of the mechanisms of resistance to new antitubercular drugs and the discovery of new effective molecules are two crucial points in tuberculosis drug discovery. In this study, we discovered a compound named RCB18350, which is active against M. tuberculosis growth and exhibits a minimum inhibitory concentration (MIC) of 1.25 μg/mL. It was also effective against multidrug-resistant isolates. We deeply studied the mechanism of resistance/action of RCB18350 by using several approaches. We found that Rv3406, an iron- and α-ketoglutarate-dependent sulfate ester dioxygenase, is capable of metabolizing the compound into its inactive metabolite. This finding highlights the role of this enzyme in the mechanism of resistance to RCB18350.

Anti-biofilm and anti-quorum sensing activities of galloylquinic acid against clinical isolates of multidrug-resistant Pseudomonas aeruginosa in open wound infection: in vitro and in vivo efficacy studies

BACKGROUND

Pseudomonas aeruginosa can proliferate in immunocompromised individuals, forming biofilms that increase antibiotic resistance. This bacterium poses a significant global health risk due to its resistance to human defenses, antibiotics, and various environmental stresses. The objective of this study was to evaluate the antibacterial, anti-biofilm, and anti-quorum sensing activities of galloylquinic acid compounds (GQAs) extracted from Copaifera lucens leaves against clinical isolates of multidrug-resistant (MDR) P. aeruginosa. We have investigated the optimal concentration of GQAs needed to eradicate preexisting biofilms and manage wound infections caused by P. aeruginosa, in vitro and in vivo.

RESULTS

Our results revealed that GQAs exhibited 25-40 mm inhibition zone diameters, with 1-4 µg/mL MIC and 2-16 µg/mL MBC values. GQAs interfered with the planktonic mode of P. aeruginosa isolates, and significantly inhibited their growth in the pre-formed biofilm architecture, with MBIC80 and MBEC80 values of 64 µg/mL and 128 µg/mL, respectively. The anti-biofilm effect was confirmed by fluorescence staining and confocal microscopy which showed a dramatic reduction in the cell viability and the biofilm thickness (62.5%), after exposure to 128 µg/mL of GQAs in particular. The scanning electron micrographs showed that GQAs impaired biofilm and bacterial structures by interfering with the biomass and the exopolysaccharides forming the matrix. GQAs also interfered with virulence factors and bacterial motility, where 128 µg/mL of GQAs significantly (p < 0.05) reduced rhamnolipid, pyocyanin, and the swarming motility of the organism which play a vital role in the biofilm formation. GQAs downregulated 89% of the quorum-sensing genes (lasI and lasR, pqsA and pqsR) involved in the biofilm formation.

CONCLUSION

GQAs demonstrate significant promise as novel and potent antibiofilm and antivirulence agents against clinical isolates of MDR P. aeruginosa, with substantial potential to enhance wound healing in biofilm-associated infections. This promising antibacterial action positions GQAs as a superior alternative for the treatment of biofilm-associated wound infections, with substantial potential to improve wound healing and mitigate the impact of persistent bacterial infections.

CLINICAL TRIAL NUMBER

not applicable.

Isolation and assessment of antibiotic resistance of Staphylococcus aureus in the air of an underground hard coal mines

Mine aerosol poses a serious health threat due to its easy access to the human respiratory tract. Damage may be caused by the chemical composition of dust and the substances adsorbed on its surface, including microorganisms that potentially affect human health. Our proposed research aimed to isolate Staphylococcus aureus strains from coal mine bioaerosol and to assess its sensitivity towards selected antibiotics. Bioaerosol samples were collected in three underground hard coal mines located in Upper Silesia in southern Poland. Microbiological tests of the air samples were carried out according to standard microbiological techniques. All tested strains of Staphylococcus aureus were sensitive to oxacillin, which indicated the lack of methicillin-resistant isolates (MRSA) in the tested group. However, antibiotic resistance from macrolide and lincosamide groups was observed among certain strains. 10% of isolates were constitutive MLSB resistance, while 4% of strains were inductive MLSB resistance. Less than 1% of isolates were erythromycin-resistant and clindamycin-sensitive (MSB). Based on the Chi-square test, statistically significant differences were found in the frequency of MSB, MLSB inductive, and MLSB constitutive phenotypes. Almost 30% of the identified strains showed multi-antibiotic resistance. However, the Chi-square test did not reveal any statistically significant differences in the frequency of multidrug-resistant strains in the considered research areas. The analyses carried out constituted the first study related to the isolation and assessment of drug susceptibility of Staphylococcus aureus in the bioaerosol of hard coal mines. Identification of bioaerosol in underground coal mines is a key issue because, due to the presence of pathogens, it plays a significant role in limiting the spread of occupational diseases. For the health of miners, research into microbial communities benefits the promotion of microbiological control of mine air.

Anticandidal Activity of Lipopeptides Containing an LL-37-Derived Peptide Fragment KR12

Candidiasis belongs to common fungal infections and is usually mild and self-limiting. However, in patients with immunodeficiencies, it can transform into invasive infections with high mortality. Long-term antifungal treatment can lead to the emergence of resistance. The problem is further complicated by the development of fungal biofilm resistant to conventional antimicrobials. Due to a limited choice of available antifungals, the development of novel active agents, such as antimicrobial peptides (AMPs), is highly desirable. Human cathelicidin LL-37 is an intensively studied AMP with a confirmed broad spectrum of antimicrobial activities. Due to the relatively high costs of production, the design of shorter analogs of LL-37 has been recommended. In this study, we synthesized a KR12 amide, KRIVQRIKDFLR-NH2, and its 24 derivatives obtained by substitution with fatty acids. The compounds were tested for their antifungal potential. They exhibited activity against the Candida albicans, C. glabrata, C. tropicalis and C. lipolytica. Five compounds: C10-KR12-NH2, C12-KR12-NH2, C14-KR12-NH2, 2-butyloctanoic acid-KR12-NH2, and 4-phenylbenzoic acid-KR12-NH2 were highly active against planktonic cells. C14-KR12-NH2 demonstrated also activity against C. albicans biofilm cultured on polystyrene for 24, 48 and 72 h. Lipidation has proven to be an effective strategy for improving microbiological activity of the KR12-NH2 peptide.

Explosive cytotoxicity of 'ruptoblasts' bridges hormonal surveillance and immune defense

Cytotoxic killing is an essential immune function, yet its cellular mechanisms have been characterized in only a few model species. Here, we show that planarian flatworms harness a unique cytotoxic strategy. In planarians, activin, a hormone regulating regeneration and reproduction, also acts as an inflammatory cytokine. Overactivation of activin signaling - through protein injection, genetic chimerism, or bacterial infection - triggers 'ruptoblasts', an undocumented immune cell type, to undergo 'ruptosis', a unique mode of cell bursting that eliminates nearby cells and bacteria in mere minutes, representing one of the fastest cytotoxic mechanisms observed. Ablating ruptoblasts suppresses inflammation but compromises bacterial clearance, highlighting ruptoblasts' broad-spectrum immune functions. We further identified ruptoblast-like cells in diverse basal bilaterians, unveiling an alternative strategy that couples hormonal regulation with immune defense and expanding the landscape of evolutionary immune innovations.

Molecular docking and mutation sites of CYP57A1 enzyme with Fomesafen

Fomesafen is a diphenyl ether herbicide developed by Zeneca Group PLC (UK), mainly used in soybean and peanut fields to control annual and perennial broad-leaved weeds. Fomesafen has strong persistence in the soil, slow degradation rate, and is prone to harm subsequent sensitive crops. This study utilized Autodock molecular docking technology to investigate the binding and interaction between degradation enzyme CYP57A1 and small molecules of fomesafen herbicides. The CYP57A1 gene cloned from a fomesafen-resistant fungus Fusarium verticilloids, belongs to a fragment of the P450 family, contains 587 bases, encodes 190 amino acids, and has an isoelectric point of 5.16. Visualization of the active surface of the protein receptor reveals that fomesafen is located in the cavity formed by the CYP57A1 protein and the cavity is small and tightly, the proteins are connected to small molecules through hydrogen bonds, halogen atom and π - cation interactions. Molecular modification of CYP57A1 enzyme was carried out using virtual amino acid mutation technology. Four key amino acids, LEU143, MET52, PHE176, and GLU177, were subjected to site-specific mutations. This study successfully constructed mutant engineered bacteria with stable protein expression. Mutations (1) MET52 > TRP showed a a decrease in enzyme activity, and the degradation rate of fomesafen was only 7.8 % of the wild-type. It is believed that MET52 is a key active site for the binding of CYP57A1 enzyme to small molecules of fomesafen, playing a crucial role in the degradation of fomesafen by this enzyme. This provides new insights into the impact on the degradation activity of fomesafen.

Antifungal effects of Metformin against Candida albicans by autophagy regulation

Candida albicans (C. albicans) is a common opportunistic fungal pathogen that can cause infections ranging from superficial to severe systemic diseases. This study investigates the antifungal effects of metformin on C. albicans and explores its underlying mechanisms. Growth inhibition was assessed via XTT assays, and hyphal formation and morphological changes were observed by light microscope and scanning electron microscopy (SEM). Mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) levels were measured with JC-1 and DCFH-DA probes, respectively. Gene expression related to ROS and autophagy was quantified by RT-qPCR, and autophagosomes were visualized using transmission electron microscopy (TEM). Metformin significantly inhibited C. albicans growth and hyphal formation, altered cell morphology, reduced MMP, and increased ROS levels. It activated autophagy in planktonic C. albicans but suppressed it in biofilm forms. Additionally, metformin exhibited synergistic effects with amphotericin B against planktonic C. albicans and with caspofungin against biofilms. The findings suggest that metformin exerts antifungal activity by modulating MMP, ROS levels, and autophagy-related pathways, and enhances the efficacy of specific antifungal drugs.

Cell death signaling in human erythron: erythrocytes lose the complexity of cell death machinery upon maturation

Over the recent years, our understanding of the cell death machinery of mature erythrocytes has been greatly expanded. It resulted in the discovery of several regulated cell death (RCD) pathways in red blood cells. Apoptosis (eryptosis) and necroptosis of erythrocytes share certain features with their counterparts in nucleated cells, but they are also critically different in particular details. In this review article, we summarize the cell death subroutines in the erythroid precursors (apoptosis, necroptosis, and ferroptosis) in comparison to mature erythrocytes (eryptosis and erythronecroptosis) to highlight the consequences of organelle clearance and associated loss of multiple components of the cell death machinery upon erythrocyte maturation. Recent advances in understanding the role of erythrocyte RCDs in health and disease have expanded potential clinical applications of these lethal subroutines, emphasizing their contribution to the development of anemia, microthrombosis, and endothelial dysfunction, as well as their role as diagnostic biomarkers and markers of erythrocyte storage-induced lesions. Fas signaling and the functional caspase-8/caspase-3 system are not indispensable for eryptosis, but might be retained in mature erythrocytes to mediate the crosstalk between both erythrocyte-associated RCDs. The ability of erythrocytes to switch between eryptosis and necroptosis suggests that their cell death is not a simple unregulated mechanical disintegration, but a tightly controlled process. This allows investigation of eventual pharmacological interventions aimed at individual cell death subroutines of erythrocytes.

Green synthesized ZnO and ZnO-based composites for wound healing applications

In recent years, zinc oxide nanoparticles (ZnO NPs) have gained much attention in biomedical applications because of their distinctive physicochemical features such as low toxicity and biocompatible properties. Traditional methods to produce ZnO NPs sometimes include harmful substances and considerable energy consumption, causing environmental issues and potential health risks. Nowadays, the concern of ZnO production has moved toward environmentally friendly and sustainable synthesis methods, using natural extracts or plant-based precursors. This review discusses the green synthesis of ZnO NPs utilizing various plant extracts for wound healing applications. Moreover, ZnO NPs have antibacterial characteristics, which can prevent infection, a substantial obstacle in wound healing. Their ability to maintain inflammation, proliferation, oxidative stress, and promote angiogenesis proves their critical role in wound closure. In addition, ZnO NPs can also be easily and ideally incorporated with wound dressings and scaffolds such as hydrogel, chitosan, cellulose, alginate, and other materials, due to their exceptional mechanical properties. The latest publication of green synthesis of ZnO NPs and their applications for wound healing has been discussed. Therefore, this review provides a current update of knowledge on the sustainable and biocompatible ZnO NPs for specific applications, i.e., wound healing applications. In addition, the green synthesis of ZnO NPs using plant extracts also provides a particular approach in terms of material preparation, which is different from previous review articles.

Microglial pyroptosis drives neuropathic pain and targeting NLRP3 alleviates pain and neuroinflammation

Neuropathic pain is triggered by nerve damage or disease and involves chronic neuroinflammation driven by activated microglia releasing pro-inflammatory cytokines. PANoptosis, a complex cell death program encompassing apoptosis, pyroptosis, and necroptosis, has emerged as a key player in neuroinflammation. While individual PANoptosis pathway have been linked to pain, its systemic role in neuropathic pain remains unclear. This study explored the involvement of PANoptosis in microglia under neuropathic pain and its potential therapeutic targeting. After spinal nerve ligation (SNL), robust microglia activation and pro-inflammatory cytokines were increased in spinal dorsal horn. To figure out the major PANoptosis under neuropathic pain, bioinformatic analysis and protein analysis were explored by using spinal dorsal horn on 14 days of post injury. The results supported that pyroptosis was the dominant pathway after injury, and we further investigated pyroptosis-related markers on microglia specifically. Notably, pyroptosis marker (caspase-1) was elevated in microglia compared to apoptosis (cleaved caspase-3) and necroptosis (p-RIPK3) markers. This finding highlights microglia pyroptosis as a key driver of neuropathic pain development. To harness this knowledge therapeutically, we employed intrathecal injection of NLRP3 siRNA nanoparticles. NLRP3, a crucial component of the inflammasome complex triggering pyroptosis, served as our target. Strikingly, this intervention effectively alleviated mechanical allodynia, a hallmark of neuropathic pain, alongside reducing microgliosis and dampening microglial pyroptosis. Our findings reveal that microglia pyroptosis plays a key role in neuropathic pain and suggest NLRP3 siRNA nanoparticles as a promising therapeutic avenue for pain management.

Cell death in glioblastoma and the central nervous system

Glioblastoma is the commonest and deadliest primary brain tumor. Glioblastoma is characterized by significant intra- and inter-tumoral heterogeneity, resistance to treatment and dismal prognoses despite decades of research in understanding its biological underpinnings. Encompassed within this heterogeneity and therapy resistance are severely dysregulated programmed cell death pathways. Glioblastomas recapitulate many neurodevelopmental and neural injury responses; in addition, glioblastoma cells are composed of multiple different transformed versions of CNS cell types. To obtain a greater understanding of the features underlying cell death regulation in glioblastoma, it is important to understand the control of cell death within the healthy CNS during homeostatic and neurodegenerative conditions. Herein, we review apoptotic control within neural stem cells, astrocytes, oligodendrocytes and neurons and compare them to glioblastoma apoptotic control. Specific focus is paid to the Inhibitor of Apoptosis proteins, which play key roles in neuroinflammation, CNS cell survival and gliomagenesis. This review will help in understanding glioblastoma as a transformed version of a heterogeneous organ composed of multiple varied cell types performing different functions and possessing different means of apoptotic control. Further, this review will help in developing more glioblastoma-specific treatment approaches and will better inform treatments looking at more direct brain delivery of therapeutic agents.

Nanoparticles in liposomes: a platform for increased antibiotic selectivity in multidrug resistant bacteria in respiratory tract infections

Antibiotic resistance is a cause of serious illness and death, originating often from insufficient permeability into gram-negative bacteria. Nanoparticles (NP) can increase antibiotic delivery in bacterial cells, however, may as well increase internalization in mammalian cells and toxicity. In this work, NP in liposome (NP-Lip) formulations were used to enhance the selectivity of the antibiotics (3C and tobramycin) and quorum sensing inhibitor (HIPS-1635) towards Pseudomonas aeruginosa by fusing with bacterial outer membranes and reducing uptake in mammalian cells due to their larger size. Poly (lactic-co-glycolic) acid NPs were prepared using emulsion solvent evaporation and incorporated in larger liposomes. Cytotoxicity and uptake studies were conducted on two lung cell lines, Calu-3 and H460. NP-Lip showed lower toxicity and uptake in both cell lines. Then formulations were investigated for suitability for oral inhalation. The deposition of NP and NP-Lip in the lungs was assessed by next generation impactor and corresponded to 75% and 45% deposition in the terminal bronchi and the alveoli respectively. Colloidal stability and mucus-interaction studies were conducted. NP-Lip showed higher diffusion through mucus compared to NPs with the use of nanoparticle tracking analyzer. Moreover, the permeation of delivery systems across a liquid-liquid interface epithelial barrier model of Calu-3 cells indicated that NP-Lip could cause less systemic toxicity upon in-vivo like administration by aerosol deposition. Monoculture and Pseudomonas aeruginosa biofilm with Calu-3 cells co-culture experiments were conducted, NP-Lip achieved highest toxicity towards bacterial biofilms and least toxicity % of the Calu-3 cells. Therefore, the NP- liposomal platform offers a promising approach for enhancing antibiotic selectivity and treating pulmonary infections.

Disruption of Pseudomonas aeruginosa quorum sensing influences biofilm formation without affecting antibiotic tolerance

The opportunistic bacterial pathogen Pseudomonas aeruginosa is a leading cause of antimicrobial resistance-related deaths, and novel antimicrobial therapies are urgently required. P. aeruginosa infections are difficult to treat due to the bacterium's propensity to form biofilms, whereby cells aggregate to form a cooperative, protective structure. Autolysis, the self-killing of bacterial cells, and the bacterial cell-to-cell communication system, quorum sensing (QS), play essential roles in biofilm formation. Strains of P. aeruginosa that have lost the lasI/R QS system commonly develop in patients, and previous studies have characterized distinctive autolysis phenotypes in these strains. Yet, the underlying causes and implications of these autolysis phenotypes remain unknown. This study confirmed these autolysis phenotypes in the PA14 QS mutant strains, ΔlasI and ΔlasR, and investigated the consequences of QS loss and associated autolysis on biofilm formation and antibiotic susceptibility. QS mutants exhibited delayed biofilm formation but ultimately surpassed the wild-type (WT) in biofilm mass. However, the larger biofilm mass of the QS mutants was not reflected in higher live-cell numbers, indicating an altered biofilm structure. Nevertheless, QS mutant biofilms were not more susceptible to antibiotics than the WT. Artificial supplementation of ΔlasI with a QS signal molecule (autoinducer) restored the strain's QS system without the associated costs of QS, enabling ΔlasI to achieve higher pre-treatment and post-treatment live-cell numbers. Overall, the lack of QS functioning was not detrimental to biofilm antibiotic tolerance, though the artificial disruption of QS may reduce the advantages of QS mutants within in vivo mixed-strain populations. Much remains to be understood regarding the regulation and induction of the autolysis phenotypes observed in these strains, and future research to fully elucidate the control and consequences of autolysis may offer potential for novel antimicrobial therapies.

Characterization of enteric pathogens in Harare, Zimbabwe using environmental surveillance and metagenomics

High diarrheal disease burden remains an urgent concern in low- and middle-income countries, greatly affecting children under the age of 5 years and those living with HIV and AIDS. Treatment of infectious diseases has also become increasingly difficult with the rapid rise of antimicrobial resistance (AMR). Environmental surveillance of wastewater can supplement gaps in clinical surveillance as residents on a sewage system contribute to the wastewater, providing simple, composite samples that can improve understanding about both pathogens and AMR in the community. This study evaluated the effectiveness of environmental surveillance with shotgun metagenomics as a tool to characterize a broad range of enteric pathogens, antibiotic resistance genes, and virulence factor genes (VFGs) in wastewater from six neighborhoods in Harare, Zimbabwe. Alpha and beta diversity of the microbial community were similar between high-income and low-income suburbs. Enteric pathogens of high AMR and clinical concern, including Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica, were detected in all samples. The top VFGs were encoded for delivery, adherence, and motility, functions important in toxin secretion, colonization, and immune modulation. The findings provide a foundation for future studies to explore environmental surveillance and shotgun metagenomics as a public health monitoring tool for enteric diseases.

Discovery of a new hydrazone-oxamide hybrid capable of inducing necroptotic cell death in triple negative breast cancer cells

The poor prognosis and inefficiency of the therapeutic agents in treating triple negative breast cancer (TNBC) have raised significant concerns, driving the quest for designing novel and potent chemotherapeutic compounds. In this regard, inducing programmed cell death (PCD) has emerged as a promising approach for breast cancer therapy. Accordingly, a series of hybrid molecules comprising hydrazone and oxamide moieties (5a-5q) were designed, synthesized, and assessed for their anticancer activity against various cancer cells. Among these synthesized hybrids, compound 5q was selected as the lead compound with remarkable ability to disrupt MDA-MB-231 cell growth, achieving an IC50-72h of 9.79 μM, while exhibiting lower toxicity in normal human cells. The in vitro experiments revealed that this compound triggers neither apoptosis nor autophagy in TNBC cells. Furthermore, the in vivo outcomes corroborated the in vitro results, showing a significant delay in tumor growth at a dose of 1 mg/kg/day following three weeks of treatment in the 4T1 mouse model of TNBC. The findings of this study suggested that compound 5q acts through necroptosis by overexpression of P-RIPK3 and phosphorylation of its downstream effector, MLKL. Compound 5q holds promise as a potential candidate for the development of anti-TNBC drugs.

The Synergistic and Chimeric Mechanism of Bacteriophage Endolysins: Opportunities for Application in Biotherapeutics, Food, and Health Sectors

A major growing concern in the human and animal health sector is the emergence of antibiotic-resistant pathogenic bacteria due to the indiscriminate use of antibiotics. The exogenous application of bacteriophage endolysins causes abrupt lysis of the bacterial cell wall, which computes them as alternatives to antibiotics. Although naturally occurring endolysins may display limitations in solubility, lytic activity, and narrow lytic spectrum, novel strategies like developing chimeric endolysins and using endolysins in synergism with other antimicrobial agents are required to improve the lytic activity of natural endolysins. The modular structure of endolysins led to the development of novel chimeric endolysins via shuffling enzymatic and cell wall binding domains of different endolysins, using endolysins in a synergistic approach, and their applications in various in vitro and in vivo experiments and different applicable areas. This article aims to review the role of chimeric endolysins and their use in synergistic mode with other biofilm-reducing agents to control biofilm formation and deteriorating pre-formed biofilms in food, dairy, and medical industries. Promoting further development of phage technology and innovation in antibiotic therapy can achieve long-term sustainable development and economic returns.

SAAP-148 Oligomerizes into a Hexamer Forming a Hydrophobic Inner Core

Human cathelicidin LL-37 derivative, the 24-mer SAAP-148, is highly effective in vitro in eradicating multidrug-resistant bacteria without inducing resistance. SAAP-148 has a high cationic charge (+11) and 46% hydrophobicity, which, once the peptide folds into an alpha helix, forms a wide hydrophobic face. This highly amphipathic nature facilitates on the one hand its insertion into the membrane's fatty acyl chain region and on the other hand it´s interaction with anionic membrane components, which aids in killing bacteria. However, the contributions of the secondary and quaternary structures have not been thoroughly investigated so far. To address this, we applied circular dichroism, NMR spectroscopy, X-ray scattering, AlphaFold 3 protein folding software, and molecular dynamics simulations. Our results reveal that SAAP-148 adopts a stable hexameric bundle composed of three parallel dimers, that together form a hydrophobic core of aromatic side chain residues. The hexameric structure is retained at the membrane interface, whereby, MD simulation studies indicated the formation of a fiber-like structure in the presence of anionic membranes. This certainly seems plausible, as oligomers are stabilized by aromatic residues, and the exposure of positively charged side chains on the surface likely facilitates the transition of the peptide into fibrils on anionic membranes.

Quinazoline-2,4(1H,3H)-dione modulates STAT3 and FOXO3a signaling in HepG2 cells

Hepatocellular carcinoma (HCC), the most prominent type of primary liver cancer, often diagnosed late, leading to poor prognosis and limited treatment options. This study investigated the anti-carcinogenic effect of Quinazoline-2,4(1H,3H)-dione (Qd), a quinazoline derivative of natural origin and identified Qd as an effective compound against HCC via STAT3 and FOXO3a signaling. STAT3 and FOXO3a are two well-known molecular drivers of HCC. In silico findings revealed Qd as the potent candidate due to its highly stable interaction with STAT3 and FOXO3a. To validate its anticancer activity, in vitro experiments were conducted on the HepG2 cell line. Qd exerts cytotoxic effect in HepG2 cells with an IC50 value of 26.07 μM, while being non-toxic in WRL-68 cells at a lower concentrations with an IC50 of 326.5 μM. Morphological changes and apoptotic cell death were confirmed using DAPI staining and Live/Dead assay. Qd also induced ROS-mediated mitochondrial damage. Qd upregulated mRNA expressions of pro-apoptotic and necroptotic markers while downregulating anti-apoptotic marker. Accordingly, the protein expression analysis demonstrated increased levels of Bax, Caspase 3, c-PARP, RIPK1, RIPK3 and MLKL, while decreasing Bcl2 and PARP expressions. Gene and protein expression of STAT3 remained at a basal level while FOXO3a gene expression increased significantly at 5 μM Qd concentration. Significant changes were particularly observed at 5 μM Qd concentration in all in vitro experiments. Despite quinazoline compounds have been shown biological and pharmacological effects, the anticancer effect of Qd is elusive till date. These in silico and in vitro findings highlighted Qd as a potent compound for further exploration in HCC therapy by targeting apoptotic and necroptotic cell death pathways.

Lichen and Its Microbiome as an Untapped Source of Anti-Biofilm Compounds

Lichen substances have been first described in the 1870s, and around 10 000 compounds have been isolated and characterized. Most of them have been evaluated for their activity on planktonic microorganisms (bacteria and fungi). More recently, microorganisms colonizing the lichen thallus have been isolated and identified using DNA sequencing, giving access to a wide diversity of culturable microorganisms. The increasing research in lichen-associated microbiomes in recent years has emphasized a wide range of metabolites as a potential source of bioactive compounds. In parallel, humans are facing microbial resistance to conventional antimicrobial drugs. One of the reasons is the biofilm lifestyle of microorganisms. Indeed, the aggregation of microbial communities inside biofilms is now well known and characterized, and some possible ways to fight and destroy biofilms are identified (quorum sensing inhibitors, etc.). The present review aims to summarize the anti-biofilm potential of lichen metabolites and those from their associated microorganisms (bacteria and/or fungi). Are the metabolites isolated from lichens and their associated fungi displaying any anti-biofilm activity? This literature synthesis highlights the metabolites of interest as new anti-biofilm drugs and shows the lack of current biological research dealing with biofilm and lichen metabolites. Acetone and ethyl acetate extracts are the most studied sources of anti-biofilm agents. Only two lichen metabolites, usnic acid and evernic acid, have been evaluated both as antifungal and antibacterial biofilm compounds. Terpenoids from lichens are still poorly explored for this activity.

Quercetin Exhibits Broad-Spectrum Antibiofilm and Antiquorum Sensing Activities Against Gram-Negative Bacteria: In Vitro and In Silico Investigation Targeting Antimicrobial Therapy

Quercetin (QC), a flavonoid abundant in fruits and vegetables, has garnered attention for its potential therapeutic properties. In this study, we investigated the antibiofilm and antiquorum sensing (QS) activities of QC against Gram-negative bacteria both in vitro and in silico. The findings of this study demonstrate MIC values of 125 μg/mL for Chromobacterium violaceum, 250 μg/mL for Pseudomonas aeruginosa, and 500 μg/mL for Serratia marcescens, indicating its antibacterial potential abilities. QS-mediated production of violacein and prodigiosin was significantly inhibited in a dose-dependent manner at sub-MIC concentrations. Additionally, a dose-dependent reduction in the virulence factors of P. aeruginosa, including production of pyocyanin, pyoverdine, and rhamnolipid, was noted with QC. Biofilm formation decreased by 66.40%, 59.28%, and 63.70% at the highest sub-MIC for C. violaceum, P. aeruginosa, and S. marcescens, respectively. Furthermore, swimming motility and exopolysaccharide (EPS) production were also reduced in the presence of QC. Additionally, molecular docking and molecular dynamics simulations elucidate the binding interactions between QC and key molecular targets (LasI, LasR, PilY1, LasA, PilT, CviR, CviR', PqsR, RhlR, and PigG) involved in biofilm formation and QS pathways. Our results indicated that the antibiofilm and anti-QS sensing activities of QC may be attributed to its ability to interfere with critical signaling molecules and regulatory proteins. Overall, this study highlights QC as a promising natural compound for combating biofilm-associated infections caused by Gram-negative bacteria. The multifaceted antimicrobial mechanisms of QC underscore its potential as a therapeutic agent for the treatment of biofilm-related infections, providing the way for further exploration, and development of QC-based strategies in antimicrobial therapy.

Prevalence of colistin-resistant Enterobacteriaceae isolated from clinical samples in Africa: a systematic review and meta-analysis

BACKGROUND

Antimicrobial resistance among Enterobacteriaceae poses a significant global threat, particularly in developing countries. Colistin, a critical last-resort treatment for infections caused by carbapenem-resistant and multidrug-resistant strains, is increasingly facing resistance due to inappropriate use of colistin and the spread of plasmid-mediated resistance genes. Despite the significance of this issue, comprehensive and updated data on colistin resistance in Africa is lacking. Thus, the current study was aimed to determine the pooled prevalence of colistin-resistant Enterobacteriaceae in Africa.

METHODS

A systematic search was conducted across PubMed, Scopus, ScienceDirect, and Google Scholar to identify relevant studies. Forty-one studies reporting on the prevalence of colistin resistance in Enterobacteriaceae isolates from clinical specimens in Africa were included in the analysis. Stata 17 software was used to calculate the pooled prevalence of colistin resistance, employing a random-effects model to determine the event rate of resistance. Heterogeneity across studies was assessed using the I2 statistic, and publication bias was evaluated using Egger's test. Subgroup analyses were performed to address any identified heterogeneity.

RESULTS

This systematic review analyzed the colistin resistance profile of 9,636 Enterobacteriaceae isolates. The overall pooled prevalence of colistin resistance was 26.74% (95% CI: 16.68-36.80). Subgroup analysis by country revealed significant variability in resistance rates, ranging from 0.5% in Djibouti to 50.95% in South Africa. Species-specific prevalence of colistin resistance was as follows: K. pneumoniae 28.8% (95% CI: 16.64%-41.05%), E. coli 24.5% (95% CI: 11.68%-37.3%), Proteus spp. 50.0% (95% CI: 6.0%-106.03%), and Enterobacter spp. 1.22% (95% CI: -0.5%-3.03%). Analysis based on AST methods revealed significant differences in colistin resistance rates (p = 0.001). The resistance rates varied between 12.60% for the disk diffusion method and 28.0% for the broth microdilution method. Additionally, a subgroup analysis of clinical specimens showed significant variation (p < 0.001) in colistin resistance. Stool specimen isolates had the highest resistance rate at 42.0%, while blood specimen isolates had a much lower resistance rate of 3.58%.

CONCLUSIONS

Colistin resistance in Enterobacteriaceae is notably high in Africa, with significant variation across countries. This underscores the urgent need for effective antimicrobial stewardship, improved surveillance, and the development of new antibiotics.

The Role and Potential Application of IL-12 in the Immune Regulation of Tuberculosis

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a significant global health challenge, affecting millions annually and leading to substantial mortality, particularly in developing countries. The pathogen's ability to persist latently and evade host immunity, combined with the emergence of drug-resistant strains, underscores the need for innovative therapeutic strategies. This review highlights the crucial role of interleukin-12 (IL-12) in coordinating immune responses against TB, focusing on its potential as an immunotherapy target. IL-12, a key Th1 cytokine, enhances cellular immunity by promoting Th1 cell differentiation and IFN-γ production, vital for Mtb clearance. By stimulating cytotoxic T lymphocytes and establishing immune memory, IL-12 supports robust host defense mechanisms. However, the complexity of IL-12 biology, including its roles in pro-inflammatory and regulatory pathways, necessitates a nuanced understanding for effective therapeutic use. Recent studies have shown how IL-12 impacts T cell synapse formation, exosome-mediated bystander activation, and interactions with other cytokines in shaping T cell memory. Genetic defects in the IL-12/IFN-γ axis link to susceptibility to mycobacterial diseases, highlighting its importance in TB immunity. The review also addresses challenges like cytokine imbalances seen in TNF-α/IFN-γ synergy, which exacerbate inflammation, and the implications for IL-12-based interventions. Research into modulating IL-12, including its use as an adjuvant and in recombinant vaccines, promises improved TB treatment outcomes and vaccine efficacy. The review concludes by stressing the need for continued investigation into IL-12's molecular mechanisms towards precision immunotherapies to combat TB and its complications.

Potential activity of paroxetine alone and associated with oxacillin as an alternative to prevent Staphylococcus aureus biofilm formation in catheters

Biofilm formation, especially in medical devices, is a pertinent factor in the virulence of Staphylococcus aureus, and is known to increase morbidity, mortality, and costs. We evaluated the activity of paroxetine, a selective serotonin reuptake inhibitor, alone and associated with oxacillin, a β-lactam antibacterial, against S. aureus biofilms, as well as verified its potential application as a preventive agent against biofilm formation in catheters. The tests were performed against mature and developing biofilms of methicillin-sensitive and -resistant S. aureus using the thiazolyl blue tetrazolium bromide reduction assay. The prevention of biofilm formation in catheters was investigated by counting colony-forming units, and scanning electron microscopy was also performed. Paroxetine caused a significant reduction in cell viability in biofilms, and when associated with oxacillin, significance was verified. Paroxetine alone and associated with oxacillin showed potential for preventing the formation of S. aureus biofilms in peripheral venous catheters, demonstrated by scanning electron microscopy, reaching inhibition of 94.94% in colony-forming units per mL. Paroxetine demonstrated promising potential against S. aureus biofilms in vitro, indicating the possibility of application as a protective agent against the formation of S. aureus biofilms in catheters.

Recent advances in research on Mycobacterium tuberculosis virulence factors and their role in pathogenesis

Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis (TB) in humans and animals. Mtb invades the host's lungs via airborne transmission, infecting macrophages and causing TB. In some cases, the infection can spread to other tissues and organs. Despite the availability of several drugs for TB treatment, the emergence of multidrug-resistant TB has led to high morbidity and mortality rates worldwide. Therefore, it is urgent to discover new anti-tuberculosis drugs for more effective treatment. Recent studies have shown that Mtb virulence factors play a crucial role in its pathogenicity. By evading the host's immune surveillance through mechanisms such as anti-oxidative stress, nutrient synthesis and metabolism, and apoptosis in host cells, Mtb can achieve long-term survival in the host. Understanding the pathogenicity mechanisms of Mtb will aid the development of new vaccines and anti-tuberculosis drugs. In this review, we summarize the latest research progress on Mtb virulence factors to provide a reference for targeted TB treatment.

Research Progress on the Antibacterial Activity of Natural Flavonoids

The use of antibiotics has greatly improved the treatment of bacterial infections; however, its abuse and misuse has led to a rapid rise in multidrug-resistant (MDR) bacteria. Therefore, the search for new antimicrobial strategies has become critical. Natural flavonoids, a class of widely existing phytochemicals, have gained significant research interest for their diverse biological activities and antibacterial effects on various drug-resistant bacteria. This review summarizes the latest research progress on flavonoids, with a particular focus on several flavonoids exhibiting certain antibacterial activity, and explores their antibacterial mechanisms, including disruption of cell membranes and cell walls, inhibition of proteins and nucleic acids, interference with signal transduction, suppression of efflux pump activity, and inhibition of biofilm formation and virulence factor production. Additionally, we have reviewed the synergistic combinations of flavonoids with antibiotics, such as the combination of quercetin with colistin or EGCG with tetracycline, which significantly enhance therapeutic efficacy.

PotF Affects the Antibacterial Activity of Plantaricin BM-1 Against Escherichia coli K12 by Modulating Biofilm Formation and Cell Membrane Integrity

Plantaricin BM-1 exhibits antibacterial activity against Escherichia coli; however, the underlying mechanism remains unclear. This study aimed to investigate the function of PotF, a putrescine-binding protein, in regulating the antibacterial activity of plantaricin BM-1 against E. coli K12. The antibacterial activity of plantaricin BM-1 against E. coli K12 and JW0838 cells was assessed using growth curves. The differences in biofilm formation between the two E. coli strains were evaluated by crystal violet staining and confocal laser scanning microscopy. The effects of plantaricin BM-1 on E. coli morphology and cell membrane integrity were investigated by electron microscopy and lactate dehydrogenase release assays. Proteomics was used to screen for differentially expressed proteins (DEPs) that are potentially involved in regulating the antibacterial mechanism. The null mutation of potF enhanced the antibacterial effects of plantaricin BM-1 on E. coli, and caused a significant decrease (p < 0.05) in the biofilms of E. coli JW0838. The plantaricin disrupted the cell membrane of E. coli JW0838. Proteomic analysis revealed that potF mutation significantly affected several DEPs involved in biofilm formation. Plantaricin BM-1 exhibited significantly enhanced antibacterial activity against biofilm-associated gene mutants compared to wild-type E. coli K12. These findings enhance our understanding of the bacteriostasis of class IIa bacteriocins against Gram-negative microorganisms.

Effect of gaseous ozone treatment on cells and biofilm of dairy Bacillus spp. isolates

Bacillus spp. can produce biofilms and cause recurrent contamination in the food industry. The common clean-in-place (CIP) method is usually employed in sanitizing processing equipment. However, CIP is not always effective in removing biofilms. Ozone represents a promising "green" alternative to control biofilms. In this study, the effect of gaseous ozone (50 ppm) was evaluated in vitro against planktonic and sessile B. cereus and B. subtilis isolates collected from the dairy sector. Planktonic cells were enumerated by plate counts after 10 min, 1 h, and 6 h of ozone treatment. After a short-term (10 min) exposure, a slight reduction in microbial loads (0.66-2.27 ± 0.15 Log10 CFU/mL) was observed for B. cereus strains, whereas a more pronounced reduction (2.90-3.81 ± 0.12 Log10 CFU/mL) was noted in B. subtilis isolates. The microbial load further decreased after 1 h-treatments, around 1.5-3.46 ± 0.11 Log10 CFU/mL for B. cereus strains, and 4.0-5.6 ± 0.11 Log10 CFU/mL for B. subtilis isolates, until complete inactivation of bacterial cells after 6 h of exposure. Moreover, the effect of gaseous ozone treatment (50 ppm, 6 h) was evaluated for its ability to inhibit and eradicate biofilms formed on two common food-contact materials (polystyrene and stainless steel). Sessile B. subtilis cells were the more sensitive to the action of ozone, while a weak effect was highlighted on B. cereus isolates on both surface types. These results were further confirmed by scanning microscopy analysis. The number of cells in the biofilm state was also assessed, showing a not-complete correlation with a decrease in Biofilm Production Indices (BPIs). These findings highlighted the effectiveness of the sanitizing protocol using gaseous ozone in contrasting Bacillus free-living cells, but a not completely counteraction in biofilm formation (inhibition) or eradication of pre-formed biofilm. Thus, the application of ozone could be thought of not alone, but in combination with common sanitization practices to improve their effectiveness.

Suppression of necroptosis-driven cell death and inflammation in hypoxic neuroblastoma (SH-SY5Y) cells by necrostatin-1

Neuroblastoma (NB) is the most typical malignant extracranial solid tumor in the pediatric population. The advent of drug resistance is an essential deterrent in treating high-risk NB patients despite a multi-modality remedy. Inflammation-induced early neuronal degeneration plays a leading part in the pathogenesis of NB via necroptosis; however, the mechanisms remained cryptic. Our current investigation determines the anti-inflammatory and neuroprotective effect of necroptosis inhibitor necrostatin-1 (Nec-1) in receptor-interacting proteins 1 and 3 (RIP1/3)-induced cell death pathway and inflammation caused by hypoxia mimetic agent cobalt chloride (CoCl2). Our biomolecular study illustrates that necroptosis marker RIP1/3 and mixed-lineage kinase domain-like pseudokinase (MLKL) protein expression was increased after treatment with CoCl2 in SH-SY5Y cells. Subsequently, elevated expression levels of RIP1/3 and MLKL further contributed to the inflammation by activating transcription factors extracellular signal-regulated protein kinase (ERK1/2), nuclear factor kappa-B (NF-κB), and releasing high levels of proinflammatory cytokines, such as vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1/CCL2). At the same time, Nec-1 treatment reduced the RIP1/3 and MLKL, phospho-ERK1/2, p65 subunit of NF-κB expression, and VEGF and MCP-1 levels. Molecular docking analysis of RIP1/3-necrostatin-1 complex highlights a significant interaction between necrostatin-1 and specific amino acid residues within the protein. Based on our promising results, necrostatin-1 could be exploited as a therapeutic agent during neuroblastoma's pathogenesis and its molecular therapy.

Anti-Planktonic, Antibiofilm, and Synergistic Effects of Nasturtium officinale and Psidium guajava Hydroethanolic Extracts Against Standard and Clinical Strains of Enterococcus faecalis

Enterococcus faecalis is strongly associated with secondary/persistent root canal infections, being the most prevalent bacterium in cases of apical periodontitis in previously treated teeth. This study was elaborated to evaluate the anti-planktonic, antibiofilm, and synergistic effects of Nasturtium officinale and Psidium guajava hydroethanolic extracts against standard and clinical strains of E. faecalis. Firstly, the N. officinale extract was prepared from watercress leaves, and P. guajava extract was prepared from guava tree leaf shoots. Then, the content of soluble solids was quantified in both. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of the isolated N. officinale and P. guajava extracts for each bacterial strain were determined using the broth microdilution method, following the Clinical and Laboratory Standards Institute (CLSI) guideline M7-A9. The MTT assay was used to evaluate the antibiofilm activity, and the fractional bactericidal concentration index (FBCI) was utilized to evaluate the synergistic effect of the N. officinale and P. guajava extracts using the checkerboard technique. Again, the MTT assay was used to evaluate the antibiofilm activity of the combined extracts this time. The data were subjected to statistical analysis using ANOVA and Tukey’s test, with a significance level of p ≤ 0.05. It was found that the soluble solid content of N. officinale was 50 mg/mL, and of P. guajava was 33.5 mg/mL. The MBC value of N. officinale was 12.5 mg/mL, and of P. guajava was 0.52 mg/mL against all the tested strains of E. faecalis. The combined 0.1 mg/mL N. officinale + 0.1 mg/mL P. guajava, and 0.1 mg/mL N. officinale + 0.5 mg/mL P. guajava hydroethanolic extracts effectively reduced the biofilm formation of the standard and clinical strain 4 of E. faecalis. Therefore, these combined extracts may be considered as endodontic irrigants in future studies.

Unlocking the potential of organopalladium complexes for high-grade serous ovarian cancer therapy

High-Grade Serous Ovarian Cancer (HGSOC) is the most common and lethal subtype of ovarian cancer, known for its high aggressiveness and extensive genomic alterations. Typically diagnosed at an advanced stage, HGSOC presents formidable challenges in drug therapy. The limited efficacy of standard treatments, development of chemoresistance, scarcity of targeted therapies, and significant tumor heterogeneity render this disease incurable with current treatment options, highlighting the urgent need for novel therapeutic approaches to improve patient outcomes. In this study we report a straightforward and stereoselective synthetic route to novel Pd(II)-vinyl and -butadienyl complexes bearing a wide range of monodentate and bidentate ligands. Most of the synthesized complexes exhibited good to excellent in vitro anticancer activity against ovarian cancer cells. Particularly promising is the water-soluble complex bearing two PTA (1,3,5-triaza-7-phosphaadamantane) ligands and the Pd(II)-butadienyl fragment. This compound combines excellent cytotoxicity towards cancer cells with substantial inactivity towards non-cancerous ones. This derivative was selected for further studies on ex vivo tumor organoids and in vivo mouse models, which demonstrate its remarkable efficacy with surprisingly low collateral toxicity even at high dosages. Moreover, this class of compounds appears to operate through a ferroptotic mechanism, thus representing the first such example for an organopalladium compound.

Dynamic Measurement of Protein Translation in Mycobacteria Using Nontargeted Stable Isotope Labeling in Combination with MALDI-TOF Mass Spectrometry-Based Readout

Understanding the metabolic pathways of mycobacteria is essential to identify novel antibiotics and to compose synergistic antibiotic regimens against tuberculosis, one of the world's most deadly infectious diseases with >1.7 Mio yearly deaths. We present a novel proteomics approach for the dynamic measurement of the nascent fractions of specific proteins. We use nontargeted stable isotope incorporation to label the nascent proteins after adding glycerol-1,3-13C2. The analysis is performed using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS) with a self-programmed script, allowing quantitative data. We compared the de novo synthesis of proteins under regular growth conditions and the effect of four antimicrobials, including rifampicin as a first-line drug, linezolid and bedaquiline as second-line drugs, and benzithiazinone-043 as promising drug candidates against tuberculosis. Changes in the synthesis of individual proteins, either due to antimicrobial action or due to regulations in the organism, can be followed in high temporal resolution within the 1/2 doubling cycle of mycobacteria. The analysis of de novo protein synthesis offers a fast screening and testing tool, allowing assessment of the onset and extent of antimycobacterial activity or regulatory phenotypes in different organisms. Due to the untargeted approach, it can be used in model strains and clinical isolates alike and does not require genetic modifications. The dynamic readout and labeling reveal the onset of action of drugs or drug candidates and allow for the prediction of synergistic effects of several substances.

Reciprocal regulation between Acinetobacter baumannii and Enterobacter cloacae AdeR homologs: implications for antimicrobial resistance and pathogenesis

Acinetobacter baumannii and Enterobacter cloacae are phylogenetically distant Gram-negative bacterial pathogens that represent significant challenges in healthcare settings due to their remarkable ability to acquire antimicrobial resistance. This study investigates one of the most important efflux pump systems in A. baumannii, AdeABC-AdeRS, and identifies homologous components in E. cloacae. By constructing isogenic knockout mutants, we show that the AdeB pump component and the AdeR regulator are significant for antimicrobial resistance and pathogenicity in A. baumannii. Through in silico predictions, we identify homologs of AdeB and AdeR (ECL_01758 and ECL_01761, respectively) in E. cloacae. Notably, we demonstrate that while the inactivation of the E. cloacae gene encoding the AdeB protein does not impact on pathogenesis and only alters colistin susceptibility, a knockout mutant of the gene encoding the AdeR regulator significantly affects susceptibility to various antimicrobial classes, motility, and virulence. Additionally, we demonstrate that the AdeR regulators of A. baumannii and E. cloacae can functionally substitute for each other both in vitro and in vivo conditions. Electrophoretic mobility shift assays reveal that these regulators are capable of binding to the promoter regions of each other's species, where similar DNA motifs are present. Furthermore, cross-complementation tests show that the affected phenotypes in each species can be restored interchangeably. Moreover, phylogenomic analysis of previously published E.cloacae genomes and reconstructrion of ancestral states through the phylogenetic trees of the adeB and adeR genes suggest that these homologs are more likely derived from a common ancestor rather than through recent horizontal gene transfer. The findings of this work highlight that conserved regulatory functions concerning efflux pump expression can be maintained across species despite evolutionary divergence and open new perspectives for the control of bacterial infections.

Uncovering synaptic and cellular nanoarchitecture of brain tissue via seamless in situ trimming and milling for cryo-electron tomography

Cell-cell communication underlies all emergent properties of the brain, including cognition, learning and memory. The physical basis for these communications is the synapse, a multi-component structure requiring coordinated interactions between diverse cell types. However, many aspects of three-dimensional (3D) synaptic organization remain poorly understood. Here, we developed an approach, seamless in situ trimming and milling (SISTM), to reliably fabricate sufficiently thin lamellae for mapping of the 3D nanoarchitecture of synapses in mouse, monkey and human brain tissue under near-native conditions via cryo-electron tomography (cryo-ET). We validated SISTM in a mouse model of Huntington's disease, demonstrating distinct 3D alterations to synaptic vesicles and mitochondria. By successfully applying SISTM to macaque brain, we described the 3D architecture of a tripartite synapse within the cortex. Subtomogram averaging (STA) enabled spatial mapping of astrocyte-neuron contacts within the tripartite synapse, revealing neurexin-neuroligin complexes as potential constituents that tether the two cell types. Finally, we showed that the defining features of synaptic nanoarchitecture were conserved across species and evident in human brain tissue obtained postmortem. Combining SISTM with cryo-ET and STA is a starting point for a new understanding of brain organization, disease-induced structural alterations and the development of rational, structure-guided therapeutics.

Hyperammonemia induces programmed liver cell death

Hyperammonemia is common in liver cirrhosis and causally associated with hepatic encephalopathy development. Little is known about its hepatotoxic effects, which we aimed to characterize in this study. In a mouse model of chronic hyperammonemia without preexisting liver disease, we observed development of liver fibrogenesis and necroptotic cell death. Hyperammonemia also induced dysregulation of its main metabolic pathway, the urea cycle, as reflected by down-regulation of urea cycle enzyme protein expression and accumulation of its metabolites. Inhibition of receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and its upstream inducer Toll-like receptor 4 (TLR4) protected against liver injury and further hyperammonemia. In clinically relevant rodent models of hyperammonemia (genetic ornithine transcarbamylase deficiency and bile duct ligation-induced cirrhosis), TLR4 inhibition reduced circulating ammonia. In conclusion, hyperammonemia induces liver fibrogenesis and RIPK1-mediated cell death, which is associated with urea cycle dysfunction. Inhibition of RIPK1 and TLR4 protects against hyperammonemia-induced liver injury and are potential therapeutic targets for hyperammonemia and chronic liver disease progression.