Antibiotic resistance: The challenges and some emerging strategies for tackling a global menace

Emergence of an unconventional Enterobacter cloacae-derived Iturin A C-15 as a potential therapeutic agent against methicillin-resistant Staphylococcus aureus

Antimicrobial resistance poses a significant global health threat by reducing the effectiveness of conventional antibiotics, particularly against pathogens like Methicillin-resistant Staphylococcus aureus (MRSA). This study investigates the antimicrobial potential of rhizospheric soil bacteria from Prosopis cineraria (Sangri) in the Thar Desert. Bacterial strains isolated from these samples were observed to produce secondary metabolites, notably, Iturin A C-15 cyclic lipopeptide (SS1-3-P) which was extracted from strain Enterobacter cloacae SS1-3 and was purified and characterized using reverse-phase HPLC, ESI-LC/MS, Nile-Red Assay, and FT-IR analysis. The presence of the Iturin A biosynthetic gene cluster was confirmed using gene-specific polymerase chain reaction and the biocompatibility of the purified product was assessed on HEK-293, WI38, and human RBCs. The potential of SS1-3-P to bind to and destroy MRSA membranes was validated using molecular dynamics simulation along with membranolysis and membrane depolarization assays. Antimicrobial assays like growth curve analysis, field emission scanning electron microscopy, and ROS generation confirmed the efficacy of SS1-3-P against clinical MRSA. Furthermore, the antibiofilm and anti-virulence properties of SS1-3-P were studied meticulously. Studies on NIH/3T3 cell lines and a murine excisional wound model showed significant wound-healing attributes of the lipopeptide. These results highlight the potential of desert ecosystems in developing effective antimicrobial therapies against recalcitrant nosocomial pathogens like MRSA.

A comprehensive review on the plant sources, pharmacological activities and pharmacokinetic characteristics of Syringaresinol

Syringaresinol, a phytochemical constituent belonging to lignan, is formed from two sinapyl alcohol units linked via a β-β linkage, which can be found in a wide variety of cereals and medicinal plants. Medical researches revealed that Syringaresinol possesses a broad spectrum of biological activities, including anti-inflammatory, anti-oxidation, anticancer, antibacterial, antiviral, neuroprotection, and vasodilation effects. These pharmacological properties lay the foundation for its use in treating various diseases such as inflammatory diseases, neurodegenerative disorders, diabetes and its complication, skin disorders, cancer, cardiovascular, and cerebrovascular diseases. As the demand for natural therapeutics increases, Syringaresinol has garnered significant attention for its pharmacological properties. Despite the extensive literature that highlights the various biological activities of this molecule, the underlying mechanisms and the interrelationships between these activities are rarely addressed from a comprehensive perspective. Moreover, no thorough comprehensive summary and evaluation of Syringaresinol has been conducted to offer recommendations for potential future clinical trials and therapeutic applications of this bioactive compound. Thus, a comprehensive review on Syringaresinol is essential to advance scientific understanding, assess its therapeutic applications, ensure safety, and guide future research efforts. This will ultimately contribute to its potential integration into clinical practice and public health. This study aims to provide a comprehensive overview of Syringaresinol on its sources and biological activities to provide insights into its therapeutic potential, and to provide a basis for high-quality studies to determine the clinical efficacy of this compound. Additionally, we explored the pharmacokinetics, toxicology, and drug development aspects of Syringaresinol to guide future research efforts. The review also discussed the limitations of current research on Syringaresinol and put forward some new perspectives and challenges, which laid a solid foundation for further study on clinical application and new drug development of Syringaresinol in the future.

Unlocking the potential of titanium dioxide nanoparticles: an insight into green synthesis, optimizations, characterizations, and multifunctional applications

This comprehensive review explores the emergence of titanium dioxide nanoparticles (TiO2-NPs) as versatile nanomaterials, particularly exploring their biogenic synthesis methods through different biological entities such as plants, bacteria, fungi, viruses, and algae. These biological entities provide eco-friendly, cost-effective, biocompatible, and rapid methods for TiO2-NP synthesis to overcome the disadvantages of traditional approaches. TiO2-NPs have distinctive properties, including high surface area, stability, UV protection, and photocatalytic activity, which enable diverse applications. Through detailed analysis, this review demonstrates significant applications of green fabricated TiO2-NPs in biomedicine, explicitly highlighting their antimicrobial, anticancer, and antioxidant activities, along with applications in targeted drug delivery, photodynamic therapy, and theragnostic cancer treatment. Additionally, the review underscores their pivotal significance in biosensors, bioimaging, and agricultural applications such as nanopesticides and nanofertilizers. Also, this review proves valuable incorporation of TiO2-NPs in the treatment of contaminated soil and water with various environmental contaminants such as dyes, heavy metals, radionuclides, agricultural effluents, and pathogens. These comprehensive findings establish the foundation for future innovations in nanotechnology, underscoring the importance of further investigating bio-based synthetic approaches and bioactivity mechanisms to enhance their efficacy and safety across healthcare, agricultural, and environmental applications.

Computational Approaches for Antimicrobial Peptide Delivery

Peptides constitute alternative molecules for the treatment of infections caused by bacteria, viruses, fungi, and protozoa. However, their therapeutic effectiveness is often limited by enzymatic degradation, chemical and physical instability, and toxicity toward healthy human cells. To improve their pharmacokinetic (PK) and pharmacodynamic (PD) profiles, novel routes of administration are being explored. Among these, nanoparticles have shown promise as potential carriers for peptides, although the design of delivery vehicles remains a slow and painstaking process, heavily reliant on trial and error. Recently, computational approaches have been introduced to accelerate the development of effective drug delivery systems for peptides. Here we present an overview of some of these computational strategies and discuss their potential to optimize drug development and delivery.

Visible-light-driven peroxydisulfate activation by biochar-loaded Fe-Cu layered double hydroxide for penicillin G degradation: Performance, mechanism and application potential

The biochar-loaded Fe-Cu layered double hydroxide (FeCu-LDH@BC) catalyst was synthesized via a simple hydrothermal method and used to activate peroxydisulfate (PDS) for penicillin G (PG) degradation under visible light. The physicochemical properties of FeCu-LDH@BC were characterized using SEM, XPS, UV-DRS, SEM-EDS, HRTEM, XRD, BET, PL spectrum, FT-IR, Raman spectrum, TG-DSC, TPD, and EIS, showing that biochar (BC) enhanced the optical properties of FeCu-LDH. Notably, the FeCu-LDH@BC + PDS + Light system achieved a 98.79% degradation efficiency for PG in just 10 min. Furthermore, FeCu-LDH@BC retained excellent activity after four reuse cycles. LSV results indicated enhanced electron transfer in the FeCu-LDH@BC + PDS + Light system, suggesting a synergistic effect between the photocatalytic and PDS activation systems. The interconversion of h+, SO4·⁻, 1O2, and ·OH species was found to play a key role in PG degradation. Density functional theory was used to identify PG sites susceptible to radical attack, and the possible degradation pathway was proposed based on liquid chromatography-mass spectrometry results. Toxicity evaluation using the TEST software confirmed that the intermediates formed were significantly less toxic than PG. Lastly, the FeCu-LDH@BC + PDS + Light system removed 37.45% of total organic carbon and 63.74% of chemical oxygen demand from real wastewater within 120 min. The type and transformation pathways of organic matter in the wastewater were analyzed using 3D Excitation Emission Matrix spectroscopy to assess the system's application potential.

Synthesis, evaluation and mechanistic insights of novel IMPDH inhibitors targeting ESKAPEE bacteria

Antimicrobial resistance poses a significant threat to global health, necessitating the development of novel therapeutic agents with unique mechanisms of action. Inosine 5'-monophosphate dehydrogenase (IMPDH), an essential enzyme in guanine nucleotide biosynthesis, is a promising target for the discovery of new antimicrobial agents. High-throughput screening studies have previously identified several urea-based leads as potential inhibitors, although many of these are characterised by reduced chemical stability. In this work, we describe the design and synthesis of a series of heteroaryl-susbtituted analogues and the evaluation of their inhibitory potency against IMPDHs. Our screening targets ESKAPEE pathogens, including Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. Several analogues with submicromolar inhibitory potency are identified and show no inhibitory potency on human IMPDH nor cytotoxic effects on human cells. Kinetic studies revealed that these molecules act as noncompetitive inhibitors with respect to the substrates and ligand virtual docking simulations provided insights into the binding interactions at the interface of the NAD+ and IMP binding sites on IMPDH.

Effects of commonly used antibiotics on children's developing gut microbiomes and resistomes in peri-urban Lima, Peru

Background

The effects of antibiotic use on children's gut microbiomes and resistomes are not well characterized in middle-income countries, where pediatric antibiotic consumption is exceptionally common. We characterized the effects of antibiotics commonly used by Peruvian children (i.e., amoxicillin, azithromycin, cefalexin, sulfa-trimethoprim) on gut diversity, genera, and antibiotic resistance gene (ARG) abundance from 3-16 months.

Methods

This study included 54 children from a prospective cohort of enteric infections in peri-urban Lima, 2016-2019. Stool collected at 3, 6, 7, 9, 12, and 16 months underwent DNA extraction and short-read metagenomic sequencing. We profiled the taxonomy of stool metagenomes and assessed ARG abundance by aligning reads to the ResFinder database. We used daily surveillance data (40,662 observations) to tabulate the number of antibiotic courses consumed in the 30 days prior to stool sampling. Using linear mixed models, the association of recent antibiotic use with species richness, diversity, gut genera, and ARG abundance over time was examined.

Results

Most children were vaginally delivered (73%), received breastmilk almost daily over the study period, and belonged to socioeconomically diverse households. Amoxicillin, azithromycin, cefalexin, and sulfa-trimethoprim did not impact gut diversity or genera abundance. Azithromycin use significantly impacted ARGs from the macrolide, aminoglycoside, and folate pathway antagonist classes. Amoxicillin use significantly increased total ARGs. Antibiotics' effects on ARGs appeared to be independent of gut microbiome changes.

Conclusion

Common antibiotics like amoxicillin and azithromycin may be key drivers of the gut resistome but not the microbiome during early childhood in this setting with frequent breastfeeding.

Predation on bacterial pathogens by predatory bacteria of sewage origin: three days prey-predator interactions

BACKGROUND

Predatory bacteria are Gram-negative microorganisms that grow within and lyse their bacterial prey. As bacterial predators have potential applications in medicine and biotechnology, the aim of this study was to isolate and identify predators from environmental samples. Therefore, three environmental bacteria belonging to the genus Bdellovibrio were isolated and characterized.

RESULTS

The predator isolates tolerated pH range from 5 to 9 well, and were killed at pH ranges of 2 and 12. They survived best at 4 °C and 29 °C, tolerated to some extent -20 °C and even -80 °C, and were completely killed at 60° C. Furthermore, the host range analysis of the predator isolates was carried out on five Gram-negative (Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Salmonella enterica) and two Gram-positive bacteria (Staphylococcus aureus, and Enterococcus faecalis). The environmental predator isolates inhibited Gram-negative preys more efficiently than Gram-positive. Predators inhibited S. enterica the most (70.48%) and P. aeruginosa the least (3.84%) among Gram-negative preys. The best inhibitory effect among Gram-positive preys was observed for S. aureus (29.83%).

CONCLUSIONS

The isolates showed broad-range predation on diverse preys under various pH and temperature conditions. Therefore, the predator isolates identified in here may be suitable choices for controlling the population of Gram-negative bacteria in different fields.

Purification of Potential Antimicrobial Metabolites from Endophytic Fusarium oxysporum Isolated from Myrtus communis

The rise of microbial resistance and emerging infections pose significant health threats. Natural products from endophytic fungi offer a promising source of novel compounds with the potential as major drug leads. This research aims to screen Myrtus communis and Moringa oleifera for endophytic fungi and screen their metabolites for antibacterial and antifungal potential. Six endophytic fungal strains were isolated using a potato dextrose agar (PDA) medium. The M. communis isolates were designated MC1, MC2, and MC3, and the M. oleifera isolates were named MO1, MO2, and MO3. Preliminary bioactivity testing revealed that the MC3 isolate exhibited significant growth inhibition against multidrug-resistant bacterial and fungal pathogens, including Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and Candida glabrata. The MC3 isolate was identified as Fusarium oxysporum through morphological and microscopic methods. For metabolite production, the fungal strain was cultured in potato dextrose broth (PDB) medium at 28 °C for 14 days in a shaking incubator. The metabolites were purified using various chromatographic techniques, HPLC and GC-MS. The GC-MS analysis of the bioactive compound containing fungal strain (F. oxysporum) revealed multiple compounds at different retention times using the NIST-20 Library. Based on RSI values and probability indices, two compounds were targeted for further purification. Structure elucidation was performed using 1D and 2D nuclear magnetic resonance (NMR) experiments on a Varian 500 NMR machine. The compounds identified were ethyl iso-allocholate (C26H44O5, exact mass 436.32) and 1-monolinoleoyl glycerol trimethylsilyl ether (C27H56O4Si2, exact mass 500.37). The MS (NIST-20) library facilitated the investigation of the in silico antimicrobial activity of these compounds against the elastase virulence protein of P. aeruginosa and protease Sapp1p from C. parapsilosis. Both the compounds were docked with druggable proteins using the Glide induced fit docking (IFD) algorithm. The ethyl iso-allocholate and 1-monolinoleoyl glycerol trimethylsilyl ether compounds showed binding scores - 10.07 kcal mol-1 and - 7.47 kcal mol-1 against elastase, and - 8.16 kcal mol-1 and - 6.89 kcal mol-1 against aspartic protease, respectively. In vitro studies confirmed the inhibitory activity of these compounds against multidrug-resistant P. aeruginosa and E. faecalis. Ethyl iso-allocholate exhibited higher bioactivity against P. aeruginosa with inhibition rates of 41%, 27%, and 35% at concentrations of 1000, 500, and 250 µg mL-1, respectively. These results suggest that bioactive compounds from F. oxysporum have the potential as antimicrobial agents, warranting further research.

Investigation of dual inhibition of antibacterial and antiarthritic drug candidates using combined approach including molecular dynamics, docking and quantum chemical methods

Emerging antibiotic resistance in bacteria threatens immune efficacy and increases susceptibility to bone degradation and arthritic disorders. In our current study, we utilized a three-layer in-silico screening approach, employing quantum chemical methods, molecular docking, and molecular dynamic methods to explore the novel drug candidates similar in structure to floroquinolone (ciprofloxacin). We investigated the interaction of novel similar compounds of ciprofloxacin with both a bacterial protein S. aureus TyrRS (1JIJ) and a protein associated with gout arthritis Neutrophil collagenase (3DPE). UTIs and gout are interconnected through the elevation of uric acid levels. We aimed to identify compounds with dual functionality: antibacterial activity against UTIs and antirheumatic properties. Our screening based on several methods, sorted out six promising ligands. Four of these (L1, L2, L3, and L6) demonstrated favorable hydrogen bonding with both proteins and were selected for further analysis. These ligands showed binding affinities of -8.3 to -9.1 kcal/mol with both proteins, indicating strong interaction potential. Notably, L6 exhibited highest binding energies of -9.10 and -9.01 kcal/mol with S. aureus TyrRS and Neutrophil collagenase respectively. Additionally, the pkCSM online database conducted ADMET analysis on all lead ligand suggested that L6 might exhibit the highest intestinal absorption and justified total clearance rate. Moreover, L6 showed a best predicted inhibition constant with both proteins. The average RMSF values for all complex systems, namely L1, L2, L3 and L6 are 0.43 Å, 0.57 Å, 0.55 Å, and 0.51 Å, respectively where the ligand residues show maximum stability. The smaller energy gap of 3.85 eV between the HOMO and LUMO of the optimized molecule L1 and L6 suggests that these are biologically active compound. All the selected four drugs show considerable stabilization energy ranging from 44.78 to 103.87 kcal/mol, which means all four compounds are chemically and physically stable. Overall, this research opens exciting avenues for the development of new therapeutic agents with dual functionalities for antibacterial and antiarthritic drug designing.

Exploring the antimicrobial potential of crude peptide extracts from Allium sativum and Allium oschaninii against antibiotic-resistant bacterial strains

CONTEXT

Plant peptides garner attention for their potential antimicrobial properties amid the rising concern over antibiotic-resistant bacteria.

OBJECTIVE

This study investigates the antibacterial potential of crude peptide extracts from 27 Thai plants collected locally.

MATERIALS AND METHODS

Peptide extracts from 34 plant parts, derived from 27 Thai plants, were tested for their antimicrobial efficacy against four highly resistant bacterial strains: Streptococcus aureus MRSA, Pseudomonas aeruginosa, Acinetobacter baumannii, and Escherichia coli. The stability of these peptide extracts was examined at different temperatures, and the synergistic effects of two selected plant peptide extracts were investigated. Additionally, the time-kill kinetics of the individual extracts and their combination were determined against the tested pathogens.

RESULTS

Peptides from Allium sativum L. and Allium oschaninii O. Fedtsch (Amaryllidaceae) were particularly potent, inhibiting bacterial growth with MICs ranging from 1.43 to 86.50 µg/mL. The consistent MICs and MBCs of these extracts across various extraction time points highlight their reliability. Stability tests reveal that these peptides maintain their antimicrobial activity at -20 °C for over a month, emphasizing their durability for future exploration and potential applications in addressing antibiotic resistance. Time-kill assays elucidate the time and concentration-dependent nature of these antimicrobial effects, underscoring their potent initial activity and sustained efficacy over time.

DISCUSSION AND CONCLUSIONS

This study highlights the antimicrobial potential of Allium-derived peptides, endorsing them for combating antibiotic resistance and prompting further investigation into their mechanisms.

A comprehensive investigation of the anion inhibition profile of a β-carbonic anhydrase from Acinetobacter baumannii for crafting innovative antimicrobial treatments

This study refers to the intricate world of Acinetobacter baumannii, a resilient pathogenic bacterium notorious for its propensity at antibiotic resistance in nosocomial infections. Expanding upon previous findings that emphasised the bifunctional enzyme PaaY, revealing unexpected γ-carbonic anhydrase (CA) activity, our research focuses on a different class of CA identified within the A. baumannii genome, the β-CA, designated as 𝛽-AbauCA (also indicated as CanB), which plays a crucial role in the resistance mechanism mediated by AmpC beta-lactamase. Here, we cloned, expressed, and purified the recombinant 𝛽-AbauCA, unveiling its distinctive kinetic properties and inhibition profile with inorganic anions (classical CA inhibitors). The exploration of 𝛽-AbauCA not only enhances our understanding of the CA repertoire of A. baumannii but also establishes a foundation for targeted therapeutic interventions against this resilient pathogen, promising advancements in combating its adaptability and antibiotic resistance.

Investigating the effect of enhanced cleaning and disinfection of shared medical equipment on health-care-associated infections in Australia (CLEEN): a stepped-wedge, cluster randomised, controlled trial

BACKGROUND

There is a paucity of high-quality evidence based on clinical endpoints for routine cleaning of shared medical equipment. We assessed the effect of enhanced cleaning and disinfection of shared medical equipment on health-care-associated infections (HAIs) in hospitalised patients.

METHODS

We conducted a stepped-wedge, cluster randomised, controlled trial in ten wards of a single hospital located on the central coast of New South Wales, Australia. Hospitals were eligible for inclusion if they were classified as public acute group A according to the Australian Institute of Health and Welfare, were located in New South Wales, had an intensive care unit, had a minimum of ten wards, and provided care for patients aged 18 years or older. Each cluster consisted of two randomly allocated wards (by use of simple randomisation), with a new cluster beginning the intervention every 6 weeks. Wards were informed of their allocation 2 weeks before commencement of intervention exposure, and the researcher collecting primary outcome data and audit data was masked to treatment sequence allocation. In the control phase, there was no change to environmental cleaning practices. In the intervention phase, a multimodal cleaning bundle included an additional 3 h per weekday for the dedicated cleaning and disinfection of shared medical equipment by 21 dedicated cleaning staff, with ongoing education, audit, and feedback. The primary outcome was the number of confirmed cases of HAI, as assessed by a fortnightly point prevalence survey and measured in all patients admitted to the wards during the study period. The completed trial is registered with Australia New Zealand Clinical Trials Registry (ACTRN12622001143718).

FINDINGS

The hospital was recruited on July 31, 2022, and the study was conducted between March 20 and Nov 24, 2023. We assessed 220 hospitals for eligibility, of which five were invited to participate, and the first hospital to formally respond was enrolled. 5002 patients were included in the study (2524 [50·5%] women and 2478 [49·5%] men). In unadjusted results, 433 confirmed HAI cases occurred in 2497 patients (17·3%, 95% CI 15·9 to 18·8) in the control phase and 301 confirmed HAI cases occurred in 2508 patients (12·0%, 10·7 to 13·3) in the intervention phase. In adjusted results, there was a relative reduction of -34·5% (-50·3 to -17·5) in HAIs following the intervention (odds ratio 0·62, 95% CI 0·45 to 0·80; p=0·0006), corresponding to an absolute reduction equal to -5·2% (-8·2 to -2·3). No adverse effects were reported.

INTERPRETATION

Improving the cleaning and disinfection of shared medical equipment significantly reduced HAIs, underscoring the crucial role of cleaning in improving patient outcomes. Findings emphasise the need for dedicated approaches for cleaning shared equipment.

FUNDING

National Health and Medical Research Council.

Differentiation Between Responders and Non-Responders to Antibiotic Treatment in Mice Using 18F-Fluorodeoxysorbitol/PET

PURPOSE

Bacterial infection causes significant mortality and morbidity worldwide despite the availability of antibiotics. Differentiation between responders and non-responders early on during antibiotic treatment will be informative to patients and healthcare providers. Our objective was to investigate whether PET imaging with 18F-Fluorodeoxysorbitol (18F-FDS) or 18F-FDG can be used to differentiate responders from non-responders to antibiotic treatment.

PROCEDURES

NTUH-K2044 was used for infection in Albino C57 female mice. Each mouse was inoculated intratracheally with NTUH-K2044 to induce lung infection (n = 8). For treatment studies, two bacterial doses for animal inoculation and two treatment starting times were compared to optimize treatment profiles. 18F-FDS or 8F-FDG /PET imaging was performed to monitor treatment progression.

RESULTS

Our results demonstrated that the treatment profiles for mice infected with 25 CFU hvKp and antibiotic treatment starting at 24 p.i. were not ideal due to no evidence of lung infection and lack of treatment efficacy. The optimal scheme is to use 250 CUF for infection and start antibiotic treatment at 24 h p.i. to monitor antimicrobial efficacy. 75% of the mice were classified as responders to antibiotic treatment. 25% of the mice were classified as non-responders. 18F-FDG was used to compare with 18F-FDS, but all mice showed increased lung uptake of 18F-FDG during 3-day treatments.

CONCLUSIONS

18F-FDS is a promising PET tracer to image bacterial infection. It can be used to monitor response to treatment, and differentiate responders from non-responders to antibiotic treatment, but 18F-FDG cannot, probably due to the presence of high degree of inflammation before and after treatment.

Imidazolium, pyridinium and pyrazinium based ionic liquids with octyl side chains as potential antibacterial agents against multidrug resistant uropathogenic E. coli

Urinary tract infections (UTIs) are the second most prevalent infectious disease with E. coli being the most common etiological agent behind these infections, affecting more than 150 million people globally each year. In recent decades, the emergence of multi-drug resistant (MDR) pathogens has rapidly escalated. To combat antimicrobial resistance (AMR), it is important to synthesize new biologically effective alternatives like ionic liquids (ILs) to control the bacterial infection and their spread. Ionic liquids are poorly coordinated organic salts characterized by melting points typically below 100 °C. The ability of ILs to form anionic and cationic interactions contributes to their versatile chemical, physical and biological attributes. In the present study, a total of 9 previously chemically synthesized and characterized ILs were used. For exploration of their antibacterial potential against the urinary tract infections (UTIs) caused by MDR Uropathogenic E. coli (UPEC) strains, in vitro and in vivo evaluation of ILs were performed. ILs showed pronounced zone of inhibition (ZOI), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 29.5 mm, 3.81 μM and 5.08 μM by agar disk diffusion and broth micro-dilution methods, respectively. Scanning electron microscopy results depicted substantial morphological changes in UPEC biofilm formation ascertaining antibiofilm potential of tested ILs. Moreover, ILs showed exceptional antioxidant potential depicted by DPPH assay along with low cytotoxic effect toward mammalian cell lines (NB4), red blood cells and whole blood. Furthermore, the gene expression analysis results justified the antibacterial potential of ILs showing down-regulation of fimH, uvrY and up-regulation of csrA gene in UPEC after ILs treatment. In vivo dermal sensitivity assessment also established their non-cytotoxic behavior. In silico analysis validated these results, with the majority of the compounds exhibiting moderate to good absorption.Due to remarkable antibacterial and antioxidant potential and negligible cytoxicity, it could be inferred that ILs could serve as novel antimicrobial alternative agents in the treatment of UTIs.

Unlocking the Potential of Pyrrole: Recent Advances in New Pyrrole-Containing Compounds with Antibacterial Potential

Nitrogen heterocycles are valuable structural elements in the molecules of antibacterial drugs approved and used to treat bacterial infections. Pyrrole is a five-atom heterocycle found in many natural compounds with biological activity, including antibacterial activity. Numerous compounds are being develop based on the pyrrole heterocycle as new potential antibacterial drugs. Due to the phenomenon of antibacterial resistance, there is a continuous need to create new effective antibacterials. In the scientific literature, we have identified the most relevant studies that aim to develop new compounds, such as pyrrole derivatives, that are proven to have antibacterial activity. Nature is an endless reservoir of inspiration for designing new compounds based on the structure of pyrrole heterocycles such as calcimycin, lynamycins, marinopyrroles, nargenicines, phallusialides, and others. However, many other synthetic compounds based on the pyrrole heterocycle have been developed and can be optimized in the future. The identified compounds were classified according to the type of chemical structure. The chemical structure-activity relationships, mechanisms of action, and antibacterial effectiveness of the most valuable compounds were highlighted. This review highlights scientific progress in designing new pyrrole-containing compounds and provides examples of lead compounds that can be successfully optimized further.

Metagenomic insights into the rapid recovery mechanisms of prokaryotic community and spread of antibiotic resistance genes after seawater disinfection

Disinfectants, such as bleaching powder, are widely employed in marine aquaculture worldwide to control the bacterial pathogens and eliminate antibiotic resistance genes (ARGs). Nevertheless, the rapid recovery of prokaryotic community compositions (PCCs) after disinfection may significantly influence the overall efficacy of disinfection. Presently, little is known about the rapid recovery mechanisms of PCCs and its impact on the removal of ARGs in seawater. In this study, 16S rRNA gene sequencing and metagenomic analysis were used to address the above concerns through simulating the disinfection process in aquaculture. The results showed that recovery of PCCs began within 16 h. The underlying mechanisms of the rapid recovery of PCCs were the synergistic interactions between microbes and the residues of disinfection-resistant bacteria (DRB). Disinfection resistance genes (DRGs) related to efflux pump serve as the primary molecular foundation providing DRB to resist disinfection. Among the 78 annotated ARGs, only 10 ARGs exhibited a significant decrease (P < 0.05) after 72 h, implying the ineffective removal of ARGs by bleaching powder. Furthermore, bacterial co-resistance to disinfectants and antibiotics was observed. Genome analysis of two highly resistant DRB from Pseudomonadaceae revealed that both DRB carried 16 DRGs, aiding the recovery of PCCs and the spread of ARGs. These findings provide novel insights in the mechanisms of the rapid recovery of PCCs and bacterial co-resistance to disinfectants and antibiotics, which can be crucial for the management of pathogens and antibiotic resistance in seawater.

Evaluating the Antimicrobial Efficacy of a Designed Synthetic peptide against Pathogenic Bacteria

Recent research has focused on discovering peptides that effectively target multidrug-resistant bacteria while leaving healthy cells unharmed. In this work, we describe the antimicrobial properties of RK8, a peptide composed of eight amino acid residues. Its activity was tested against multidrug-resistant Gram-negative and Gram-positive bacteria. RK8's efficacy in eradicating mature biofilm and increasing membrane permeability was assessed using Sytox Green. Cytotoxicity assays were conducted both in vitro and in vivo models. Circular dichroism analysis revealed that RK8 adopted an extended structure in water and sodium dodecyl sulfate (SDS). RK8 exhibited MICs of 8-64 μM and MBCs of 4-64 μM against various bacteria, with higher effectiveness observed in Methicillin-resistant Staphylococcus aureus (MRSA) and E. coli KPC+ strains than others. Ciprofloxacin and Vancomycin showed varying MIC and MBC values lower than RK8 for Gram-positive bacteria, but competitive for Gram-negative bacteria. The combination of RK8 and ciprofloxacin showed a synergistic effect. The RK8 peptides could reduce 38% of the mature Acinetobacter baumannii biofilm. Sytox Green reagent achieved 100% membrane permeation of Gram-positive and Gram-negative bacteria. The RK8 peptide did not show cytotoxic effects against murine macrophages (64 μM), erythrocytes (100 μM) or Galleria mellanella larvae (960 μM). In the stability test against peptidases, the RK8 peptide was stable, maintaining around 60% of the molecule intact after 120 min of incubation. These results highlight the potential of RK8 to be a promising strategy for developing a new antimicrobial and antibiofilm agent, inspiring and motivating further research in antimicrobial peptides.

Enhanced Efficacy of Some Antibiotics in the Presence of Silver Nanoparticles Against Clinical Isolate of Pseudomonas aeruginosa Recovered from Cystic Fibrosis Patients

Introduction

Given the increasing frequency of drug-resistant bacteria and the limited progress in developing new antibiotics, it is necessary to explore new methods of combating microbial infections. Nanoparticles, particularly silver nanoparticles (Ag-NPs), have shown exceptional antibacterial characteristics; however, elevated concentrations of Ag-NPs can produce noticeable levels of toxicity in mammalian cells.

Aim

This study examined the potential synergistic effect of combining a low dosage of Ag-NPs and anti-pseudomonas drugs against Pseudomonas aeruginosa (ATCC strain) and eleven clinical isolates from cystic fibrosis patients.

Methods

The Ag-NPs were chemically produced by utilizing a seed extract from Peganum Harmala and characterized via ultraviolet-visible spectroscopy and scanning electron microscopy. The broth microdilution technique was utilized to investigate the minimum inhibitory concentration (MIC) of Ag-NPs and eight antibiotics (Piperacillin, Ciprofloxacin, Levofloxacin, Meropenem, Amikacin, Ceftazidime, Gentamicin, Aztreonam). The fractional inhibitory concentration index (FICI) was determined via the checkerboard method to evaluate the synergistic effects of Ag-NPs and various antibiotics.

Results

The biosynthesized Ag-NPs were uniformly spherical and measured around 15 nm in size. When combined with antibiotics, Ag-NP produced statistically significant reductions in the amount of antibiotics required to completely prevent P. aeruginosa growth for all strains. The findings revealed that the MIC of Ag-NPs was 15 ug/mL for all strains which decreased substantially when administered with antibiotics at a dose of 1.875-7.5 ug/mL. The majority of Ag-NP and antibiotic combinations exhibited a synergistic or partially synergistic impact. This was particularly noticeable in combinations containing Meropenem, Ciprofloxacin, and Aztreonam (in which the FIC index was less than or equal to 0.5).

Conclusion

The findings revealed that combining Ag-NPs with antibiotics was more effective than using Ag-NPs or antibiotics in isolation and that combinations of Ag-NPs and antimicrobial agents displayed synergistic activity against the majority of strains assessed.

Eco-friendly synthesis of ZnO nanoparticles fabricated using Fioria vitifolia L. and their biomedical potentials

The present study aimed to environmentally friendly synthesis of ZnO NPs using Fioria vitifolia leaf extracts which provides a sustainable and green approach for production of NPs. The produced ZnO NPs were evaluated using various spectrum approaches (UV-vis, FTIR XRD, TEM and EDAX). The synthesized ZnO NPs was confirmed by UV-Visible spectroscopy exhibited a peak at 370 nm. SEM imaging revealed a flash-like and needle-like bottom morphology. Fourier-transform infrared spectroscopy (FTIR) analysis detected vibrations corresponding to alcohols, halides, and aromatics functional groups. TEM showed spherical-shaped NPs with an average diameter of 11 nm. XRD analysis exhibited distinct peaks at 2θ values of 31.7°, 34.3°, 36.2°, 47.4°, 56.6°, 62.8°, 66.4°, 67.9°, 69.1°, and 76.8°, corresponding to the crystallographic planes (100), (002), (101), (102), (110), (103), (200), (112), (201), (004), and (202) planes respectively. The antibacterial activity demonstrated significant zones of inhibition against E. coli (17 ± 0.6 mm) and S. aureus (23.7 ± 0.5 mm), and inhibition of biofilm formation in S. aureus and C. albicans. Additionally, S. mutans exhibited the highest sensitivity to the minimum inhibitory concentration (MIC) of ZnO NPs, with complete inhibition occurring at 7.5 μg/mL. Furthermore, antioxidant DPPH assays exhibited IC50 values of 42 μg/mL. Additionally, the anti-inflammatory properties of ZnO NPs of F. vitifolia were evaluated in-vitro using models utilizing the human red blood cells (HRBC) membrane stabilization method (MSM), and it was shown to have an MSM of 83.87 % at 250 μg/mL. Furthermore, ZnO NPs exhibited anticancer activity against the MDA-MB-231 breast cancer cell line with an IC50 value of 35.50 μg/mL. Toxicological evaluation of FV-ZnO nanoparticles in zebrafish (Danio rerio) embryos indicated low toxicity at maximum concentration. These is first findings suggest that ZnO NPs synthesized from F. vitifolia leaf extracts possess significant antibacterial, antioxidant, anti-inflammatory, and anticancer properties. Additionally, their low toxicity in zebrafish embryos makes them suitable for further development in antimicrobial therapies with minimal side effects, offering a sustainable, biocompatible solution to tackle multidrug-resistant microbial infections.

Structural, DFT, Molecular Docking and Biological Activity of New Albendazole-Norfloxacin Mixed-Ligand Complexes: Promising Metal Complexes for Combating Microbial Resistance and Inflammation

This study presents a comprehensive characterization of the Fe(III) (C1) and Co(II) (C2) complexes that were synthesized from the Albendazole (Alb) and Norfloxacin (Nor) ligands. The complexes exhibit remarkable thermal stability, low water solubility, and a non-electrolytic nature, characteristics that enhance their suitability for diverse applications. Conductivity measurements indicate molar conductivities of 9.85 and 8.59 Ω-1 cm2 mol-1, confirming their status as neutral molecules. Fourier Transform Infrared (FTIR) spectroscopy reveals significant ligand-metal interactions, marked by shifts in vibrational frequencies that confirm chelation, while Ultraviolet-Visible (UV-Vis) spectroscopy supports the identification of octahedral geometries for both complexes. Magnetic moment assessments align with their electronic configurations, and stoichiometric analysis consistently shows a 1:1:1 ratio, further validated by mass spectrometry. Thermal stability studies highlight anhydrous characteristics and distinct thermal decomposition behaviors, underscoring their structural integrity. Employing Density Functional Theory (DFT) calculations using the B3LYP functional, we evaluate the electronic properties of the ligands and their metal complexes, revealing reduced energy gaps (ΔE) of 2.29 eV for C1 and 2.15 eV for C2, significantly lower than those of the ligands (Alb: 4.61 eV, Nor: 4.17 eV), indicating enhanced reactivity and potential biological activity. Additionally, molecular electrostatic potential (MEP) maps provide insights into charge distributions, suggesting critical regions for interactions with biomolecules. Notably, the results demonstrate that metal coordination significantly enhances antibacterial/anti-fungal activity surpassing both the free ligands and the standard antibiotic Ofloxacin/Fluconazole. Furthermore, the complexes show significant improvement in anti-inflammatory activity by inhibiting protein denaturation more effectively than their ligand counterparts. Molecular docking studies reveal stronger binding affinities and interactions with antimicrobial target proteins 1HNJ and 5IKT, attributed to enhanced hydrophobic interactions and hydrogen bonding. These findings position C1 and C2 as promising candidates for developing effective antimicrobial therapies, highlighting the crucial role of metal ions in enhancing biological reactivity and addressing resistant strains of pathogens.

Phage therapeutic delivery methods and clinical trials for combating clinically relevant pathogens

The ongoing global health crisis caused by multidrug-resistant (MDR) bacteria necessitates quick interventions to introduce new management strategies for MDR-associated infections and antimicrobial agents' resistance. Phage therapy emerges as an antibiotic substitute for its high specificity, efficacy, and safety profiles in treating MDR-associated infections. Various in vitro and in vivo studies denoted their eminent bactericidal and anti-biofilm potential. This review addresses the latest developments in phage therapy regarding their attack strategies, formulations, and administration routes. It additionally discusses and elaborates on the status of phage therapy undergoing clinical trials, and the challenges encountered in their usage, and explores prospects in phage therapy research and application.

Tackling antibiotic resistance-insights from eHealthResp's educational interventions

Antibiotic resistance (AR) poses a significant challenging issue in public health worldwide. This phenomenon led to the emergence of antibiotic-resistant bacterial strains, making the treatment of respiratory infections increasingly difficult. Educational interventions targeting healthcare professionals are important to improve prescription practices and promote responsible antibiotic use. Digital tools, including clinical decision support systems and mobile applications, have proven to effectively enhance educational interventions and clinical decision-making. The eHealthResp project is one such initiative that includes an online course and a mobile app designed to improve antibiotic use for upper respiratory tract infections (URTIs). The online course provides clinical information and case studies, whereas the mobile app acts as a clinical decision support system for URTIs diagnosis. The purpose of this study is to analyse the utilization patterns of eHealthResp digital tools among primary care physicians and community pharmacists. Results showed that both physicians and pharmacists (n = 35) had favorable progress and high grades when completing the online course assessment. The mobile app data indicated a diverse range of searched cases with different respiratory symptoms, with the most common being acute nasal discharge and pain when swallowing. Most observations presented mild symptoms for less than seven days, suggesting the occurrence of acute self-limited infections. Despite limitations, digital tools show promise in enhancing patient care outcomes for managing URTIs. Future efforts should focus on expanding participation among health professionals and enhancing educational interventions to promote responsible antibiotic use.

In-Vitro Antimicrobial Activities of Grape Seed, Green Tea, and Rosemary Phenolic Extracts Against Liver Abscess Causing Bacterial Pathogens in Cattle

Liver abscesses, which occur in finishing cattle, are of significant economic concern to the feedlot industry. The causative agents include both Fusobacterium necrophorum subspecies (F. necrophorum and F. funduliforme), Trueperella pyogenes (T. pyogenes), and Salmonella enterica serotype Lubbock (S. Lubbock). Tylosin, a macrolide antibiotic, is supplemented in the feed to reduce liver abscesses. However, due to the concern with emergence of antimicrobial resistance, the antimicrobial activities of the plant-based phenolic compounds could be an antibiotic alternative to control liver abscesses. We investigated the inhibitory activities of phenolic compounds extracted from grape seed, green tea, and rosemary on liver-abscess-causing bacterial pathogens. Total phenolic content was determined spectrophotometrically. Anaerobic Brain-Heart Infusion broth (for Fusobacterium) and Muller-Hinton broth (for S. enterica and T. pyogenes) with phenolic extracts at 0, 0.1, 1, and 2 mg/mL were prepared. Growth was measured at 0, 12, 24 and 48 h by determining bacterial concentrations. A micro-broth dilution method was used to quantify the inhibition. Grape seed and green tea phenolics inhibited growth of both Fusobacterium subspecies, T. pyogenes and S. enterica. Green tea at 1 mg/mL concentration was more effective in inhibiting the growth of Fusobacterium when compared to grape seed and rosemary. Green tea at 2 mg/mL was more effective than at 1 mg/mL against Salmonella. The inhibitory effect was dose-dependent, which was consistent across all strains within the same bacterial species. The phenolic extracts were inhibitory against T. pyogenes with minimum inhibitory concentration ranging from 6.25 to 12.5 µg/mL. Among the phenolic extracts tested, green tea showed the most potent activity, suggesting its strong potential as a natural alternative to conventional antibiotics. Plant-based phenolic compounds supplemented in the feed may have the potential to control liver abscesses.

Utility of preoperative prophylactic antibiotics for preventing surgical site infections in children with infantile hypertrophic pyloric stenosis: a systematic review and meta-analysis

PURPOSE

The aim of this study was to determine the utility of prophylactic antibiotics before pyloromyotomy for the prevention of Surgical Site Infections (SSI) among children with Infantile Hypertrophic Pyloric Stenosis (IHPS).

METHODS

A systematic search of PubMed, Scopus, Embase, and Web of Science databases was performed to identify papers published till 30th July 2024. The main outcome of interest was the incidence of SSIs. The relative risk (RR) with 95% confidence interval (CI) was calculated using a random effects model. The I2 statistic was used to calculate the heterogeneity. The Newcastle-Ottawa-Scale (NOS) was used to assess the methodological quality of the included studies.

RESULTS

Five studies, published between 1999 and 2024, were included in this systematic review and meta-analysis. The risk of developing SSI among those treated was RR = 0.97, 95% CI 0.53 to 1.78, with I2 = 0%, indicating no incremental benefit of administration of prophylactic antibiotics. A sensitivity analysis was performed by excluding the database studies. Results from this analysis (RR = 0.79, 95% CI 0.29 to 2.20, I2 = 0%) demonstrated that no significant difference was observed after excluding studies with large sample sizes. All included studies were of good methodological quality as assessed with the NOS.

CONCLUSION

The findings of this review demonstrate no incremental benefit of the administration of prophylactic antibiotics before pyloromyotomy in preventing SSIs in children with IHPS. However, randomized, double-blinded, placebo-controlled trials need to be conducted in the future before any definite conclusions are drawn in this regard.

Structure-based drug design of pre-clinical candidate nanopiperine: a direct target for CYP1A1 protein to mitigate hyperglycaemia and associated microbes

Diabetes is attributed to an increased vulnerability to bacterial infection linked to unregulated hyperglycaemia. The present study highlights the formulation of nanoparticles with phyto-compound piperine (PIP) encapsulated within non-toxic biodegradable polymer poly-lactide co-glycolide (PLGA) which showed a variety in surface functionality, biocompatibility, and the ability to tailor an optimized release rate from its polymeric enclosure. The observations revealed that nanopiperine (NPIP) pre-treatment in mice inhibited alteration in hepatic tissue architecture and hepato-biochemical parameters in diabetes and its associated bacterial infections. NPIP also decreased the propensity of lipids to undergo an oxidation process and stabilized the membrane lipids in vivo, thereby lowering oxidative stress and preventing enzymatic activation of CYP1A1. This result is corroborated with the in silico molecular docking study where PIP binding with CYP1A1 gave -11.32 Kcal/mol dock score value. The antibacterial activity of PIP was further demonstrated by the in silico PIP and Ef-Tu protein-binding efficacy revealing -6.48 Kcal/mol score value which was coupled with the results of in vitro studies where the zone of inhibition assay with NPIP against Staphylococcus aureus and Escherichia coli. Thus, NPIP could serve as a potential drug candidate in modulating targeted proteins to inhibit the progression of hyperglycaemia and its associated microbes.

Genomic insights into fish pathogenic bacteria: A systems biology perspective for sustainable aquaculture

Fish diseases significantly challenge global aquaculture, causing substantial financial losses and impacting sustainability, trade, and socioeconomic conditions. Understanding microbial pathogenesis and virulence at the molecular level is crucial for disease prevention in commercial fish. This review provides genomic insights into fish pathogenic bacteria from a systems biology perspective, aiming to promote sustainable aquaculture. It covers the genomic characteristics of various fish pathogens and their industry impact. The review also explores the systems biology of zebrafish, fish bacterial pathogens, and probiotic bacteria, offering insights into fish production, potential vaccines, and therapeutic drugs. Genome-scale metabolic models aid in studying pathogenic bacteria, contributing to disease management and antimicrobial development. Researchers have also investigated probiotic strains to improve aquaculture health. Additionally, the review highlights bioinformatics resources for fish and fish pathogens, which are essential for researchers. Systems biology approaches enhance understanding of bacterial fish pathogens by revealing virulence factors and host interactions. Despite challenges from the adaptability and pathogenicity of bacterial infections, sustainable alternatives are necessary to meet seafood demand. This review underscores the potential of systems biology in understanding fish pathogen biology, improving production, and promoting sustainable aquaculture.

Microbial profiling, antimicrobial resistance surveillance, and molecular detection of MecA gene in Staphylococcal strains from donor human milk: Insights from a milk bank investigation

PURPOSE

Donor human milk (DHM) from milk banks provides vital nutrition to vulnerable infants. Understanding its microbial profile and antimicrobial resistance patterns is crucial for ensuring its safety and efficacy. This study aimed to profile the microbial composition, detect antibiotic resistance, and identify the presence of mecA gene in Staphylococcal strains from DHM samples.

MATERIALS AND METHOD

A total of 151 DHM samples were collected from a regional human milk bank in North India. Microbial identification was performed using MALDI TOF MS, and antimicrobial susceptibility testing was conducted using the disc diffusion method. Molecular methods, including PCR, were employed for mecA gene detection.

RESULTS

The study revealed a diverse microbial profile, with Staphylococcus species being predominant. Acinetobacter and Pseudomonas species were also prevalent, raising concerns due to their association with healthcare-associated outbreaks. High rates of antibiotic resistance were observed across both Gram-positive and Gram-negative bacteria, with resistance to commonly used antibiotics such as penicillin, clindamycin, erythromycin, and ceftriaxone. The mecA gene, associated with methicillin resistance, was detected in a significant proportion of Staphylococcal isolates.

CONCLUSION

The study underscores the importance of rigorous microbial analysis and antimicrobial susceptibility testing in assessing the safety of DHM. The presence of diverse microbial species, including antibiotic-resistant strains and the mecA gene in Staphylococcal strains, emphasizes the need for stringent hygiene practices and continuous surveillance in milk banks. Implementing comprehensive screening protocols and adhering to best practices in milk handling and pasteurization are crucial for safeguarding the health of vulnerable infants reliant on donor milk.

Guanethidine Enhances the Antibacterial Activity of Rifampicin Against Multidrug-Resistant Bacteria

The escalating global threat of antibiotic resistance necessitates innovative strategies, such as the combination of antibiotics with adjuvants. Monotherapy with rifampicin is more likely to induce resistance in pathogens compared to other antibiotics. Herein, we found that the antihypertensive drug guanethidine enhanced the activity of rifampicin against certain clinically resistant Gram-negative bacteria, resulting in a reduction of up to 128-fold in the minimum inhibitory concentration. In infected animal models, this combination has achieved treatment benefits, including increased survival and decreased bacterial burden. The antimicrobial mechanism of guanethidine in synergy with rifampicin involves the disruption of the outer membrane of Gram-negative bacteria, leading to dissipation of the proton motive force. This results in an increase in reactive oxygen species and a reduction in ATP synthesis, severely disturbing energy metabolism and ultimately increasing bacterial mortality. In summary, guanethidine has the potential to become a novel adjuvant for rifampicin, offering a new option for the treatment of clinical Gram-negative bacterial infections.

The clinical praxis of bacteriocins as natural anti-microbial therapeutics

In recent decades, the excessive use of antibiotics has resulted in a rise in antimicrobial drug resistance (ADR). Annually, a significant number of human lives are lost due to resistant infectious diseases, leading to around 700,000 deaths, and it is estimated that by 2050, there could be up to 10 million casualties. Apart from their possible application as preservatives in the food sector, bacteriocins are gaining acknowledgment as potential clinical treatments. Not only this, these antimicrobial peptides have revealed in modulating the host immune system producing anti-inflammatory and anti-modulatory responses. At the same time, due to the ever-increasing global threat of antibiotic resistance, bacteriocins have gained attraction among researchers due to their potential clinical applications. Bacteriocins as antimicrobial peptides, represent one of the most important natural defense mechanisms among bacterial species, particularly lactic acid bacteria (LAB), that can fight against infection-causing pathogens. In this review, we are highlighting the potential of bacteriocins as novel therapeutics for inhibiting a wide range of clinically relevant and multi-drug-resistant pathogens (MDR). We also highlight the effectiveness and potential applications of current bacteriocin treatments in combating antimicrobial resistance (AMR), thereby promoting human health.

Antibiofilm and antivirulence potentials of iodinated fmoc-phenylalanine against Staphylococcus aureus

Staphylococcus aureus poses significant risks to public health due to its ability to form biofilm and produce virulence factors, contributing to the increase in antibiotic resistance and treatment complications. This emphasizes the urgent need for novel antimicrobial controls. Based on the premise that halogenation improves antimicrobial efficacy, this study investigated the ability of halogenated phenylalanine to effectively inhibit S. aureus biofilm formation and virulence activities. Among 29 halogenated compounds, Fmoc-4-iodo-phenylalanine (Fmoc-Iodo-Phe) displayed the highest antibiofilm effect against S. aureus, achieving 94.3 % reduction at 50 μg/mL. Microscopic studies confirmed its ability to prevent and disrupt mature biofilms. At 10 μg/mL, Fmoc-Iodo-Phe markedly inhibited virulence factors, such as cell surface hydrophobicity, hemolysin and slime production. It showed low propensity for resistance development and effectively inhibited biofilms formed by methicillin-resistant S. aureus (MRSA) and S. epidermidis, but was inactive against Gram-negative bacteria. Gene expression analysis complemented by molecular docking suggest that Fmoc-Iodo-Phe could target the AgrA quorum sensing cascade due to strong interactions with key residues at its DNA binding sites. Notably, it was non-cytotoxic in Caenorhabditis elegans model and satisfied drug-likeliness criteria based on ADMET prediction. Therefore, our findings position Fmoc-Iodo-Phe as a promising antimicrobial candidate against S. aureus infections, underscoring its potential as an alternative to traditional antibiotics.

Insect Cuticle Protein Nanoassemblies without Nonspecific Immune Response for Acute Methicillin-Resistant Staphylococcus aureus Pneumonia Remission

The emergence and proliferation of methicillin-resistant Staphylococcus aureus (MRSA) pneumonia poses a significant global public health threat. Herein, the significant remission effect against acute MRSA pneumonia was realized through the insect cuticle protein (OfCPH-2) nanoassemblies without nonspecific immune response. The lung repair results could be attributed to the transforming of M1-type to M2-type macrophage polarization and the repression of Th17 cell differentiation in mice spleens through the intervention of OfCPH-2 nanoassemblies. These findings offer a valuable insight into the application of insect protein-based materials as effective antidrug resistant strain agents as well as a powerful strategy for acute MRSA pneumonia.

Antimicrobial Resistance: What Lies Beneath This Complex Phenomenon?

Antimicrobial Resistance (AMR) has evolved from a mere concern into a significant global threat, with profound implications for public health, healthcare systems, and the global economy. Since the introduction of antibiotics between 1945 and 1963, their widespread and often indiscriminate use in human medicine, agriculture, and animal husbandry has led to the emergence and rapid spread of antibiotic-resistant genes. Bacteria have developed sophisticated mechanisms to evade the effects of antibiotics, including drug uptake limitation, drug degradation, target modification, efflux pumps, biofilm formation, and outer membrane vesicles production. As a result, AMR now poses a threat comparable to climate change and the COVID-19 pandemic, and projections suggest that death rates will be up to 10 million deaths annually by 2050, along with a staggering economic cost exceeding $100 trillion. Addressing AMR requires a multifaceted approach, including the development of new antibiotics, alternative therapies, and a significant shift in antibiotic usage and regulation. Enhancing global surveillance systems, increasing public awareness, and prioritizing investments in research, diagnostics, and vaccines are critical steps. By recognizing the gravity of the AMR threat and committing to collaborative action, its impact can be mitigated, and global health can be protected for future generations.

Identification and Assessment of Secondary Metabolites from Three Fungal Endophytes of Solanum mauritianum Against Public Health Pathogens

Fungal endophytes, symbiotic microorganisms residing within plants, are renowned for producing bioactive secondary metabolites with diverse beneficial properties. We investigated the antimicrobial potential of fungal endophytes isolated from Solanum mauritianum, an invasive weed, against clinically significant bacterial pathogens. Selected fungal endophytes (Penicillium chrysogenum, Fusarium sp., and Paracamarosporium leucadendri) were isolated from the plant's leaves and fruits. Their crude extracts were tested against various referenced strains, such as Mycobacterium species (M. smegmatis ATCC 607 and M. bovis ATCC 27290), Staphylococcus aureus ATCC 6571, Bacillus subtilis ATCC 11774, Klebsiella species (K. pneumoniae ATCC 10031 and K. oxytoca ATCC 8724), Escherichia coli ATCC 10536, and Pseudomonas aeruginosa ATCC 10145, using the Kirby-Bauer disk diffusion method. Resazurin Microtiter Assay was used for the determination of the minimum inhibitory concentration. The chemical nature of the secondary metabolites in the crude extracts produced by fungal endophytes was evaluated using high-resolution liquid chromatography-mass spectrometry (LC-MS) using water and acetonitrile gradient. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS) was employed for untargeted metabolomics. LC-QTOF-MS/MS identified 63 bioactive compounds across the three endophytes. P. chrysogenum had the highest activity against S. aureus and M. smegmatis (1.15 mg/mL and 0.02 mg/mL, respectively), while P. leucadendri demonstrated moderate activity against M. smegmatis (2.91 mg/mL) and E. coli (1.16 mg/mL). Fusarium sp. exhibited the broadest spectrum of antibacterial activity, with MIC values ranging from 0.03 mg/mL (B. subtilis) to 10 mg/mL (M. smegmatis). P. leucadendri produced 29 metabolites, Fusarium sp. had 23 identified metabolites, and a total of 11 metabolites were identified from P. chrysogenum. The fruits of the plant, accounting for 60%, appeared to be the most abundant in the endophyte diversity when compared to the stems and leaves. This study highlights the potential of fungal endophytes from S. mauritianum as a source of novel bioactive compounds, particularly against multidrug-resistant pathogens, contributing to the ongoing efforts to combat antimicrobial resistance.

Pragmatic randomised trial assessing the impact of peer comparison and therapeutic recommendations, including repetition, on antibiotic prescribing patterns of family physicians across British Columbia for uncomplicated lower urinary tract infections

OBJECTIVE

To evaluate the impact of a personalised audit and feedback prescribing report (AF) and brief educational summary (ES) on empiric treatment of uncomplicated lower urinary tract infections (UTIs) by family physicians (FPs).

DESIGN

Cluster randomised control trial.

SETTING

The intervention was conducted in British Columbia, Canada between 23 September 2021 and 28 March 2022.

PARTICIPANTS

We randomised 5073 FPs into a standard AF and ES intervention arm (n=1691), an ES-only arm (n=1691) and a control arm (n=1691).

INTERVENTIONS

The AF contained personalised and peer-comparison data on first-line antibiotic prescriptions for women with uncomplicated lower UTI and key therapeutic recommendations. The ES contained detailed, evidence-based UTI management recommendations, incorporated regional antibiotic resistance data and recommended nitrofurantoin as a first-line treatment.

MAIN OUTCOME MEASURES

Nitrofurantoin as first-line pharmacological treatment for uncomplicated lower UTI, analysed using an intention-to-treat approach.

RESULTS

We identified 21 307 cases of uncomplicated lower UTI among the three trial arms during the study period. The impact of receiving both the AF and ES increased the relative probability of prescribing nitrofurantoin as first-line treatment for uncomplicated lower UTI by 28% (OR 1.28; 95% CI 1.07 to 1.52), relative to the delay arm. This translates to additional prescribing of nitrofurantoin as first-line treatment, instead of alternates, in an additional 8.7 cases of uncomplicated UTI per 100 FPs during the 6-month study period.

CONCLUSION

AF prescribing data with educational materials can improve primary care prescribing of antibiotics for uncomplicated lower UTI.

TRIAL REGISTRATION NUMBER

NCT05817253.

Guanethidine Restores Tetracycline Sensitivity in Multidrug-Resistant Escherichia coli Carrying tetA Gene

The worrying issue of antibiotic resistance in pathogenic bacteria is aggravated by the scarcity of novel therapeutic agents. Antibiotic adjuvants offer a promising solution due to their cost-effectiveness and high efficacy in addressing this issue, such as the β-lactamase inhibitor sulbactam (a β-lactam adjuvant) and the dihydrofolate reductase inhibitor trimethoprim (a sulfonamide adjuvant). This study aimed to discover potential adjuvants for tetracyclines from a list of previously approved drugs to restore susceptibility to Escherichia coli carrying the tetA gene. We have screened guanethidine, a compound from the Chinese pharmacopoeia, which effectively potentiates the activity of tetracyclines by reversing resistance in tetA-positive Escherichia coli, enhancing its antibacterial potency, and retarding the development of resistance. Guanethidine functions via the inhibition of the TetA efflux pump, thereby increasing the intracellular concentration of tetracyclines. Our findings suggest that guanethidine holds promise as an antibiotic adjuvant.

Bacterial isolates from drinking water river sources exhibit multi-drug resistant trait

Freshwater habitat is a natural reservoir for antimicrobial resistance (AMR). AMR poses serious human, animal, and environmental public health threats. This study aimed to evaluate the physicochemical and microbiological quality of five selected rivers (Apitipiti 1, Apitipiti 2, Apitipiti 3, Sogidi, and Aba Apa Akinmorin) in Oyo town, Nigeria, as well as the antibiotic resistance pattern of isolated bacterial species, using conventional methods. Most physicochemical parameters were within WHO and NIS permissible limits. Pearson's correlation matrix indicated that there were significant (p < 0.05) interactions among pH, electrical conductivity, temperature, sulphate and chloride salts, and BOD and COD. A total of thirty-two (32) bacterial species were isolated and identified as: Aeromonas (9), Bacillus (2), Corynebacterium (13), Lactobacillus (1), Pseudomonas (2), Staphylococcus (4), and Streptococcus (1). Of the rivers, Sogidi had the highest microbial load (6.36 log CFU/mL) while Apititipiti 1 had the lowest (5.76 log CFU/mL). With regard to antibiotic sensitivity, 81.8% were multidrug-resistant, with Corynebacterium kutscheri and Aeromonas spp. isolated from Apitipiti 2 and Aba Apa Akinmorin rivers, respectively, exhibiting a relatively high antibiotic resistance of 90.9%. This study reveals that these rivers may be unfit for consumption as multidrug-resistant bacteria of public health risk were associated with them.

De Novo Design of Tryptophan Containing Broad-Spectrum Cationic Antimicrobial Octapeptides

With the advent of antibiotic resistant organisms, development of alternate classes of molecules other than antibiotics to combat microbial infections, have become extremely important. In this context, antimicrobial peptides have taken center stage of antimicrobial therapeutic research. In this work, we have reported two cationic antimicrobial octapeptides WRL and LWRF, with broad spectrum antimicrobial activities against several strains of ESKAPE pathogens. Both the peptides were membrane associative and induced microbial cell death through membranolysis, being selective towards microbial membranes over mammalian membranes. The AMPs were unstructured in water, adopting partial helical conformation in the presence of microbial membrane mimics. Electrostatic interaction formed the primary basis of peptide-membrane interactions. WRL was more potent, salt tolerant and faster acting of the two AMPs, owing to the presence of two tryptophan residues against that of one in LWRF. Increased tryptophan number in WRL enhanced its membrane association ability, resulting in higher antimicrobial potency but lower selectivity. This experimental and computational work, established that an optimum number of tryptophan residues and their position was critical for obtaining high antimicrobial potency and selectivity simultaneously in the designed cationic AMPs. Understanding the peptide membrane interactions in atomistic details can lead to development of better antimicrobial therapeutics in future.

Gating-Enhanced Hierarchical Structure Learning in Hyperbolic Space and Multi-scale Neighbor Topology Learning in Euclidean Space for Prediction of Microbe-Drug Associations

Identifying drug-related microbes may help us explore how the microbes affect the functions of drugs by promoting or inhibiting their effects. Most previous methods for the prediction of microbe-drug associations focused on integrating the attributes and topologies of microbe and drug nodes in Euclidean space. The heterogeneous network composed of microbes and drugs has a hierarchical structure, and the hyperbolic space is helpful for reflecting the structure. However, the previous methods did not fully exploit the structure. We propose a multi-space feature learning enhanced microbe-drug association prediction method, MFLP, to fuse the hierarchical structure of microbe and drug nodes in hyperbolic space and the multiscale neighbor topologies in Euclidean space. First, we project the nodes of the microbe-drug heterogeneous network on the sphere in hyperbolic space and then construct a topology which implies hierarchical structure and forms a hierarchical attribute embedding. The node information from multiple types of neighbor nodes with the new topological structure in the tangent plane space of a sphere is aggregated by the designed gating-enhanced hyperbolic graph neural network. Second, the gate at the node feature level is constructed to adaptively fuse the hierarchical features of microbe and drug nodes from two adjacent graph neural encoding layers. Third, multiple neighbor topological embeddings for each microbe and drug node are formed by neighborhood random walks on the microbe-drug heterogeneous network, and they cover neighborhood topologies with multiple scales, respectively. Finally, as each scale of topological embedding contains its specific neighborhood topology, we establish an independent graph convolutional neural network for the topology and form the topological representations of microbe and drug nodes in Euclidean space. The comparison experiments based on cross validation showed that MFLP outperformed several advanced prediction methods, and the ablation experiments verified the effectiveness of MFLP's major innovations. The case studies on three drugs further demonstrated MFLP's ability in being applied to discover potential candidate microbes for the given drugs.

Bioconjugation of Serratiopeptidase with Titanium Oxide Nanoparticles: Improving Stability and Antibacterial Properties

Antimicrobial resistance (AMR) poses a significant global health threat, necessitating the development of novel antibacterial strategies. Serratiopeptidase (SP), a metalloprotease produced by bacteria such as Serratia marcescens, has gained attention not only for its anti-inflammatory properties but also for its potential antibacterial activity. However, its protein nature makes it susceptible to pH changes and self-proteolysis, limiting its effectiveness. This study aimed to increase both the enzymatic stability and antibacterial activity of serratiopeptidase through immobilization on titanium oxide nanoparticles (TiO2-NPs), leveraging the biocompatibility and stability of these nanomaterials. Commercial TiO2-NPs were characterized using TGA/DTG, FT-IR, UV-Vis, and XRD analyses, and their biocompatibility was assessed through cytotoxicity studies. Serratiopeptidase was produced via fermentation using the C8 isolate of Serratia marcescens obtained from the intestine of Bombyx mori L., purified chromatographically, and immobilized on carboxylated nanoparticles via EDC/NHS coupling at various pH conditions. The optimal enzymatic activity was achieved by using pH 5.1 for nanoparticle activation and pH 5.5 for enzyme coupling. The resulting bioconjugate demonstrated stable proteolytic activity at 25 °C for 48 h. Immobilization was confirmed by FT-IR spectroscopy, and the Michaelis-Menten kinetics were determined. Notably, the bioconjugate exhibited two-fold greater antibacterial activity against E. coli than the free enzyme or TiO2-NPs at 1000 µg/mL. This study successfully developed a serratiopeptidase-TiO2 bioconjugate with enhanced enzymatic stability and antibacterial properties. The improved antibacterial activity of the immobilized enzyme presents a promising approach for developing new tools to combat antimicrobial resistance, with potential applications in healthcare, food safety, and environmental protection.

LL-37 and bisphosphonate co-delivery 3D-scaffold with antimicrobial and antiresorptive activities for bone regeneration

This study introduces a novel 3D scaffold for bone regeneration, composed of silk fibroin, chitosan, nano-hydroxyapatite, LL-37 antimicrobial peptide, and pamidronate. The scaffold addresses a critical need in bone tissue engineering by simultaneously combating bone infections and promoting bone growth. LL-37 was incorporated for its broad-spectrum antimicrobial properties, while pamidronate was included to inhibit bone resorption. The scaffold's porous structure, essential for cell infiltration and nutrient diffusion, was achieved through a freeze-drying process. In vitro assessments using SEM and FTIR confirmed the scaffold's morphology and chemical integrity. Antimicrobial efficacy was tested against pathogens of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa). In vivo studies in a murine model of infectious bone defect revealed the scaffold's effectiveness in reducing inflammation and bacterial load, and promoting bone regeneration. RNA sequencing of treated specimens provided insights into the molecular mechanisms underlying these observations, revealing significant gene expression changes related to bone healing and immune response modulation. The results indicate that the scaffold effectively inhibits bacterial growth and supports bone cell functions, making it a promising candidate for treating infectious bone defects. Future studies should focus on optimizing the release of therapeutic agents and evaluating the scaffold's clinical potential.

Genome sequencing and analysis of penicillin V producing Penicillium rubens strain BIONCL P45 isolated from India

BACKGROUND

A filamentous fungus Penicillium rubens is widely recognized for producing industrially important antibiotic, penicillin at industrial scale.

OBJECTIVE

To better comprehend, the genetic blueprint of the wild-type P. rubens was isolated from India to identify the genetic/biosynthetic pathways for phenoxymethylpenicillin (penicillin V, PenV) and other secondary metabolites.

METHOD

Genomic DNA (gDNA) was isolated, and library was prepared as per Illumina platform. Whole genome sequencing (WGS) was performed according to Illumina NovoSeq platform. Further, SOAPdenovo was used to assemble the short reads validated by Bowtie-2 and SAMtools packages. Glimmer and GeneMark were used to dig out total genes in genome. Functional annotation of predicted proteins was performed by NCBI non-redundant (NR), UniProt, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Ontology (GO) databases. Moreover, secretome analysis was performed by SignalP 4.1 and TargetP v1.1 and carbohydrate-active enzymes (CAZymes) and protease families by CAZy database. Comparative genome analysis was performed by Mauve 2.4.0. software to find genomic correlation between P. rubens BIONCL P45 and Penicillium chrysogenum Wisconsin 54-1255; also phylogeny was prepared with known penicillin producing strains by ParSNP tool.

RESULTS

Penicillium rubens BIONCL P45 strain was isolated from India and is producing excess PenV. The 31.09 Mb genome was assembled with 95.6% coverage of the reference genome P. chrysogenum Wis 54-1255 with 10687 protein coding genes, 3502 genes had homologs in NR, UniProt, KEGG, and GO databases. Additionally, 358 CAZymes and 911 transporter coding genes were found in genome. Genome contains complete pathways for penicillin, homogentisate pathway of phenyl acetic acid (PAA) catabolism, Andrastin A, Sorbicillin, Roquefortine C, and Meleagrin. Comparative genome analysis of BIONCL P45 and Wis 54-1255 revealed 99.89% coverage with 2952 common KEGG orthologous protein-coding genes. Phylogenetic analysis revealed that BIONCL P45 was clustered with Fleming's original isolate P. rubens IMI 15378.

CONCLUSION

This genome can be a helpful resource for further research in developing fermentation processes and strain engineering approaches for high titer penicillin production.

Antimicrobial effects of a multimodal wound matrix against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa in an in vitro and an in vivo porcine wound model

Chronic non-healing wounds pose significant challenges due to an elevated inflammatory response caused in part by bacterial contamination (Physiol Rev. 2019;99:665). These wounds lead to billions being spent in the health care system worldwide (N Engl J Med. 2017;376:2367, Int J Pharm. 2014;463:119). We studied the in-vitro and in-vivo antimicrobial effects of a multimodal wound matrix (MWM) against two common wound pathogens, Methicillin-Resistant Staphylococcus aureus (MRSA USA300) and Pseudomonas aeruginosa ATCC 27312 (PA27312) (Int Wound J. 2019;16:634). The in-vitro study conducted was a zone of inhibition test with the two microbes at 104 Log CFU/mL inoculated on Tryptic soy agar with 5% sheep blood (TSAII) plates. Treatments used were MWM, Mupirocin (Positive control for MRSA), Silver Sulfadiazine (Positive Control for PA), Petrolatum and Sterile Saline (both serving as Negative Controls). Treatments were allowed to diffuse into the agar for 3 h and then were incubated for 24 h at 37°C. The in-vivo study utilized a deep dermal porcine wound model (22 × 22 × 3 mm) created on six animals. Three animals were inoculated with MRSA USA300 and the other three with PA27312 with each allowing a 72-h biofilm formation. After 72 h, baseline wounds were assessed for bacterial concentration and all remaining wounds were treated with either MWM alone, Silver Treatment or Untreated Control. Wounds were assessed on days 4, 8 and 12 after treatment application for microbiological analysis. In-vitro, MWM exhibited significant inhibition of MRSA USA300 and PA27312 growth when compared to negative controls (p ≤ 0.05). Likewise, in-vivo, the MWM-treated wounds exhibited a significant (p ≤ 0.05) bacterial reduction compared to all other treatment groups, especially on days 8 and 12 for both pathogens. MWM demonstrated promise in addressing colonized wounds with biofilms. Additional studies on MWM's benefits and comparisons with existing treatments are warranted to optimize wound care strategies (Adv Wound Care. 2021;10:281).

Characterization of Antibiotic Resistance Profiles in the Oral Microbiota of the Pakistani Population

Background The oral microbiota's resistance to antibiotics presents a serious threat to world health, especially in developing nations where misuse of antibiotics is common. Objective The objective of this study was to characterize the antibiotic resistance profiles in the oral microbiota of Pakistani adults. Methodology The Department of Microbiology at Akhtar Saeed Medical and Dental College in Lahore, Pakistan, carried out a cross-sectional study from January 2022 to December 2022. Oral swabs were collected from 240 adults (aged 18 and older) who had not used antibiotics in the past three months. The disk diffusion method was used for both antibiotic susceptibility testing and bacterial cultures. Descriptive statistics and logistic regression analysis were conducted using IBM SPSS Statistics for Windows, Version 25 (Released 2017; IBM Corp., Armonk, New York, United States) to examine associations within the demographic data. Results The study examined 240 participants, comprising 133 students (55.42%), 64 professionals (26.67%), and 43 individuals in other occupations (17.92%). Of the participants, 128 were male (53.33%) and 112 were female (46.67%). With 81 isolates (33.75%), Streptococcus mutans was the most common species of bacterium, followed by Staphylococcus aureus with 69 isolates (28.75%). The majority of cases (n = 72; 30.00%) were resistant to penicillin, followed by erythromycin (22.50%) in 54 instances and tetracycline (19.58%) in 47 cases. Age group (50 years and above; β = 0.120, OR = 1.128, p = 0.017), penicillin resistance (β = 0.150, OR = 1.162, p = 0.001), erythromycin resistance (β = 0.120, OR = 1.128, p = 0.013), and ciprofloxacin resistance (β = 0.130, OR = 1.139, p = 0.014) were all significantly associated with the results of the regression analysis. Additionally, resistance was positively associated with the occupation "student" (β = 0.110, OR = 1.116, p = 0.047). Conclusion The high levels of antibiotic resistance observed, particularly in older age groups and certain occupations, underscore the urgent need for enhanced antibiotic stewardship and regulatory measures in Pakistan.

Exploring Drug Resistance: Microbial Profiles, Antibiotic Sensitivity, and Biofilm Development in Orthopedic Implant Infections

Background With the advent of and rise in antibiotic resistance globally, especially in postoperative patients, studying the antibiogram and associated factors is the need of the hour. The present study was undertaken to document the microbiological profile in postoperative orthopedic patients with the infected implant in situ and to observe the antibiotic susceptibility patterns of isolated organisms in such infections. Methods This study was conducted in the Department of Microbiology of a tertiary care hospital for six months after obtaining institutional ethical approval. A total of 236 samples from patients with orthopedic implant infections were received during the study period, out of which 53 samples with positive culture isolate were further analyzed for microbiological profile including biofilm production. All observations and demographics were recorded and analyzed using SPSS software version 21.0 (IBM Corp., Armonk, NY, USA) and represented in the form of graphs, data, and tables. Results and conclusion The study showed a culture positivity rate of 53 (23%) out of 236 samples, in which gram-negative isolates 36 (68%) were more than gram-positive isolates 17 (32%). The most common isolate was staphylococcus aureus 17 (32%) of which the majority were MRSA 13 (76%), followed by Escherichia coli 9 (17%) and Klebsiella pneumoniae 9 (17%). Out of the 53 isolates, 20 were biofilm producers. Biofilm-producing isolates were more resistant to tested routine antibiotics compared to non-biofilm. This study could represent the initial interdisciplinary effort in an ongoing process to better understand and manage orthopedic implant infections at the hospital, specifically focusing on infections related to orthopedic devices.

Critical review on plant-derived quorum sensing signaling inhibitors in pseudomonas aeruginosa

Pseudomonas aeruginosa, a biofilm-forming organism with complex quorum mechanisms (Las, Rhl, PQS, and IQS), poses an imminent danger to the healthcare sector and renders current treatment options for chemotherapy ineffectual. The pathogen's diverse pathogenicity, antibiotic resistance, and biofilms make it difficult to eradicate it effectively. Quorum sensing, a complex system reliant on cell density, controls P. aeruginosa's pathogenesis. Quorum-sensing genes are key components of P. aeruginosa's pathogenic arsenal, and their expression determines how severe the spread of infection becomes. Over the past ten years, there has been a noticeable increase in the quest for and development of new antimicrobial medications. Quorum sensing may be an effective treatment for infections triggered by bacteria. Introducing quorum-sensing inhibitors as an anti-virulent strategy might be an intriguing therapeutic method that can be effectively employed along with current medications. Amongst the several speculated processes, a unique anti-virulence strategy using anti-quorum sensing and antibiofilm medications for targeting pseudomonal infestations seems to be at the forefront. Due to their noteworthy quorum quenching capabilities, biologically active phytochemicals have become more well-known in the realm of science in this context. Recent research showed how different phytochemical quorum quenching actions affect P. aeruginosa's QS-dependent pathogenicity. This review focuses on the most current data supporting the implementation of plant bio-actives to treat P.aeruginosa-associated diseases, as well as the benefits and future recommendationsof employing them in anti-virulence therapies as a supplementary drug development approach towards conventional antibiotic approaches.

The TELCoMB Protocol for High-Sensitivity Detection of ARG-MGE Colocalizations in Complex Microbial Communities

Understanding the genetic basis of antimicrobial resistance is crucial for developing effective mitigation strategies. One necessary step is to identify the antimicrobial resistance genes (ARGs) within a microbial population, referred to as the resistome, as well as the mobile genetic elements (MGEs) harboring ARGs. Although shotgun metagenomics has been successful in detecting ARGs and MGEs within a microbiome, it is limited by low sensitivity. Enrichment using cRNA biotinylated probes has been applied to address this limitation, enhancing the detection of rare ARGs and MGEs, especially when combined with long-read sequencing. Here, we present the TELCoMB protocol, a Snakemake workflow that elucidates resistome and mobilome composition and diversity and uncovers ARG-MGE colocalizations. The protocol supports both short- and long-read sequencing and does not require enrichment, making it versatile for various genomic data types. TELCoMB generates publication-ready figures and CSV files for comprehensive analysis, improving our understanding of antimicrobial resistance mechanisms and spread. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Installing TELCOMB Locally Alternate Protocol: Installing TELCOMB on a SLURM Cluster Basic Protocol 2: Data Preprocessing Basic Protocol 3: Calculation of Resistome Distribution and Composition Basic Protocol 4: Identification of ARG-MGE Colocalizations.

Gut colonization by extended-spectrum β-lactamase-producing Escherichia coli in dairy herd in Brazil: successful dissemination of a One Health clone

The overuse of antimicrobials in livestock has contributed to the emergence and selection of clinically relevant multidrug-resistant bacteria. In Brazil, there is no conclusive information on the occurrence of Escherichia coli producing extended-spectrum β-lactamase (ESβL) in cattle breeding, which is an important sector of agribusiness in this country. Herein, we investigated the presence of ESβL-positive E. coli strains in dairy cattle from a commercial farm with routine practice of therapeutic cephalosporins. Ninety-five rectal swab samples were collected from healthy dairy calves and cows under treatment with ceftiofur. Samples were screened for the presence of ESβL producers, and positive isolates were identified by MALDI-TOF, with subsequent screening for genes encoding ESβL variants by PCR and sequencing. The presence of ESβL (CTX-M-15)-producing E. coli was confirmed in calves, and lactating and dry cows. Most ESβL strains with genetic homologies ≥ 90% were grouped into two major PFGE clusters, confirming the suscessful expansion of clonally related lineages in animals from different lactating cycles, on the same property. Four representatives CTX-M-15-positive E. coli strains had their genomes sequenced, belonging to the clonal complex (CC) 23 and sequence type (ST) 90. A phylogeographical landscape of ST90 was performed revealing a global One Health linkage. Our results highlight the intestinal microbiota of dairy cattle as a hotspot for the spread of critical priority ESβL-producing E. coli and demonstrate that ST90 is an international clone genomically adapted to human and animal hosts, which deserve additional investigation to determine its zoonotic potential and impact in food chain.

Ellagic acid-modified gold nanoparticles to combat multi-drug resistant bacterial infections in vitro and in vivo

The overuse of antibiotics has led to the rapid development of multi-drug resistant bacteria, making antibiotics increasingly ineffective against bacterial infections. Consequently, there is an urgent need to develop alternative strategies to combat multi-drug-resistant bacterial infections. In this study, gold nanoparticles modified with ellagic acid (EA-AuNPs) were prepared using a simple and mild one-pot hydrothermal process. EA-AuNPs demonstrated high bactericidal efficacy and broad-spectrum antimicrobial activities against clinical isolates of the antibiotic-resistant ESKAPE pathogens. Furthermore, EA-AuNPs effectively disperse biofilms of multi-drug-resistant bacteria. Additionally, EA-AuNPs mitigated inflammatory responses at the bacterial infection sites. The combined bactericidal and anti-inflammatory treatment with EA-AuNPs resulted in faster curing of peritonitis caused by Staphylococcus aureus in mice compared to treatment with free EA or gentamicin. Moreover, transcriptome analysis revealed that EA-AuNPs exhibited a multi-targeting mechanism, making resistance development in pathogens more challenging than traditional antibiotics that recognize specific cellular targets. Overall, EA-AuNPs emerged as a promising antimicrobial agent against multi-drug-resistant bacterial infections.