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A unique species of pine, Cedrus deodara is known for its wood oil. Its traditional therapeutic use is mainly antibacterial and anti-inflammatory. The aim of this study was to investigate the antibacterial properties of Cedrus deodara essential oil (CDEO) obtained from the crushed wood. The antimicrobial activity of CDEO was evaluated against Gram-negative (G-) bacteria which included Pseudomonas aeruginosa CCM 1595, Salmonella enterica subs. enterica CCM 3807 and Gram-positive (G+) bacteria Yersinia enterocolitica CCM 5671. Listeria monocytogenes CCM 4699, Staphylococcus aureus subs. aureus CCM 2461 and Streptococcus consellatus CCM 4043 in vitro and in situ. The best antimicrobial activity for the disc diffusion method ranged from 4.67 to 9.67 mm and the minimum inhibitory concentration ranged from 1.48 to 5.44 mg.mL-1. The most effective antimicrobial effect was found against S. aureus and L. monocytogenes. The vapour phase used showed the best antimicrobial effect against P. aeruginosa in the kiwifruit model and L. monocytogenes in the banana model at a lower CDEO concentration of 62.5 µg.L-1 and against P. aeruginosa in the potato model and Y. enterocolitica in the cucumber model at a higher CDEO concentration of 500 µg.L-1. CDEO showed good antimicrobial activity against bacteria on vegetable and fruit model and may be a new preservative for storage of vegetables and fruits. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials, such as carbon quantum dots (CQDs), are excellent candidates for antibacterial agent development as they are cost-effective. Nitrogen-doped CQDs (N-doped CQDs) exhibit antibacterial activity against gram-positive bacteria. However, investigation of N-CQDs and their efficacy against the selected bacterial strains under visible light irradiation has not been carried out. Here, we aimed to evaluate N-CQDs for their efficacy as a photosensitizer for antimicrobial photodynamic therapy (aPDT). N-CQDs were synthesized using the hydrothermal method with 1,3,6-trinitropyrene (TNP) as the nitrogen and carbon source. Antimicrobial tests of N-CQDs were conducted against gram-positive (Bacillus subtilis NCIB 3610, Staphylococcus aureus Newman, and S. aureus USA300) and gram-negative (Escherichia coli K12) bacteria at different concentrations (0–100 mg/L). The N-CQDs exerted a moderate growth-inhibitory effect on gram-positive bacteria in the dark. However, in the presence of white light generated using 20-W light-emitting diode, N-CQDs could completely kill the bacteria at a low concentration of 20 mg/L. The minimal inhibitory concentration of N-CQDs for the two S. aureus strains (Newman and USA300) was 20 mg/L under light conditions, whereas that for B. subtilis was 100 mg/L. The results demonstrate that N-CQDs may be used as a photosensitizer in aPDT and as an antibacterial agent. [Display omitted] • Nitrogen-doped carbon quantum dots (N-CQDs) were produced by the hydrothermal method. • N-CQDs exerted moderate growth-inhibitory effect on gram-positive bacteria in dark. • Incubation with N-CQDs under the white light could completely kill the bacteria. • N-CQDs may be used as an antibacterial agent in antibacterial photodynamic therapy. [ABSTRACT FROM AUTHOR]

The goal of this study is to investigate the antibacterial activity and sustained release of Centella Asiatica (CA) extract loaded in gelatin-based hydrogels, reinforced with MIL-53(Fe) (Fe-MOF) for the potential use as wound dressing. To induce antibacterial activity to the designed wound dressing, CA-extract was incorporated within the nanocomposite hydrogels. FT-IR analysis showed the distinctive peaks related to the Fe-MOF and CA-extract, with little shift, for hydrogel samples, which confirm the successful synthesis of nanocomposite hydrogels containing Fe-MOF and CA-extract. GC-mass analysis showed the antibacterial potential for CA-extract because of the presence of phenol, caryophyllene, and propanoic acid. SEM micrograph demonstrates the presence of Fe-MOF enhancing the porous of hydrogels. The antibacterial activity of prepared nanocomposite hydrogels was investigated by disk diffusion method revealing the significant inhibition zone growth for Basillus, Staphylococcus, and Streptococcus, as gram-positive and E. coli, Klebsiella, and P. aeruginosa as gram-negative bacteria and the "Candida albicans as fungi. Also, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by the micro-broth dilution method. The results showed that the nanocomposite hydrogel has a MIC values of 3.125 mg/ml and 6.25 mg/ml against both groups of bacteria. Cytotoxicity results obtained from MTT tests showed that the prepared hydrogels are biocompatible. The immunohistochemistry-stained hydrogel images revealed that the growth of cells on the CA-extract containing hydrogels was significantly increased in comparison to neat hydrogels. [ABSTRACT FROM AUTHOR]

In the present work, flexible polymeric nanocomposite film of poly(vinyl alcohol)/poly(ethylene glycol) (PVA–PEG) blend filled with aluminum (Al)-doped zinc oxide (AZO) nanoparticles has been successfully synthetized and characterized. The solution casting technique was used to prepare pure PVA–PEG polymeric blend and polymeric blend nanocomposite (PNC) films filled with different concentrations of AZO nanoparticles. The morphological, structural and optical properties of AZO NPs and PNC films were investigated using different techniques such as X-ray diffraction (XRD) scanning electron microscopy (SEM), transmission electron microscopy (TEM) spectroscopy and UV–VIS–NIR spectrophotometer. The XRD results shows that nanoparticles are well distributed in the host blend matrix. TEM observation reveals an average particle size about 49 nm. The contact angle analysis was carried out for PNC films to investigate the effect of AZO filling upon the nanocomposite water wettability. Loading PNC with nanopowder AZO influences their electrical optical properties. The addition of AZO nanoparticles in the polymeric blend reduces its band gap and increases its DC electrical conductivity. The antibacterial activity of the prepared nanocomposite films was tested against various pathogenic bacteria including two types of gram-positive bacteria (Staphylococcus aureus (S. aureus) and Bacillus) and two types of gram-negative bacteria (Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli)). The assay results suggested that the pure blend film has no activity against all types of bacteria. While filled PNC films exhibit a significant antibacterial activity against S. aureus, Bacillus and P. aeruginosa bacteria, they have no any activity against E. coli bacteria. This activity is improved with increasing the filler concentrations in blend matrix. Finally, the obtained results suggest that the prepared PNC films can be a potential multifunctional candidate for different applications, especially optoelectronic devices and biomedical uses. [ABSTRACT FROM AUTHOR]

Enterococci are Gram-positive coccus bacteria that are normally present in the gastrointestinal tract and ordinarily function commensally with humans. Very few studies have investigated the characteristics of enterococcal infections. We aimed to characterize patients with urinary tract infections (UTIs) due to Enterococci and their outcomes. This was a retrospective cohort study between June 2012–November 2022. Patients who had clinically and microbiologically confirmed Enterococcal UTI based on a urine culture positive for E. faecalis or E. faecium with a count of ≥105 CFU/mL and having urinary tract symptoms were included. A total of 396 patients were eligible and included. The patients had a median age of 61 years and were mostly females (56.8 %). The most common characteristics were hospitalization in a non-ICU ward, having a urinary catheter, and recent use of antibiotics within the last 3 months (66.4 %, 59.3 %, and 51.8 %, respectively). Infection with E. faecalis was more common than E. faecium (77.3 % vs. 22.7 %). However, the latter exhibited higher rates of antibiotic resistance (P < 0.001 to several antibiotics) and was associated with significantly higher median C-reactive protein level (26.7 vs. 13 mg/dL; P = 0.025), mortality (23 % vs. 10.1 %; P = 0.002), and median length of stay (25 vs. 11.5 days; P < 0.001). We found that most patients with enterococcal UTIs had a history of having a urinary catheter and recent antibiotic use and were mostly females and hospitalized in non-ICU wards. E. faecium -infected patients experienced more severe episodes and poorer outcomes compared to patients infected with E. faecalis ; thus, would need more aggressive therapy. [ABSTRACT FROM AUTHOR]

Lepidium perfoliatum seed gum (LPSG) biopolymer was co-electrospun in a hybrid nanofiber (HNF) structure using polyvinyl alcohol and polycaprolactone polymers. The obtained results showed the improvement in the hydrophilicity of HNFs with an increase in the LPSG content. In-vitro assay showed two stages of degradation of HNFs (34% and 4% weight loss within 24 h and 14 days, respectively). The antibacterial assay also showed the antibacterial activity of HNFs against Gram-positive and Gram-negative bacteria species. The biocompatibility of the LPSG-based nanofibers was also justified by the MTT assay against L929 fibroblast cells (97.4% cell viability). [ABSTRACT FROM AUTHOR]

In recent years, there has been an exponential increase in the production of silver bionanoparticles due to their widespread commercialization and technological applications. However, there is limited understanding of the impact of silver bionanoparticles on biological agents commonly used in wastewater treatment, particularly in waste stabilization ponds (WSPs). This study aimed to synthesize new silver nanoparticles (sg-AgNPs) from Synadenium glaucescens root using an environmentally friendly method and optimized biosynthesis parameters, and evaluate their antimicrobial activity and ecotoxicological impact on WSPs using standardized approaches. The average primary sizes of the sg-AgNPs in the five samples were not significantly different (P > 0.05), indicating the effectiveness of the eco-friendly method and the importance of optimal biosynthesis conditions. Analysis from UV–Vis spectroscopy, energy-dispersive spectroscopy (EDX), transmission electron microscope (TEM), and X-ray diffraction (XRD) confirmed that sg-AgNPs exhibited typical characteristics of green silver nanoparticles. Furthermore, sg-AgNPs showed strong antimicrobial activity (MIC, 0.012–0.094 mg/ml) against gram-positive bacteria (Escherichia coli), gram-negative bacteria (Staphylococcus aureus), non-filamentous fungi (Candida albicans) and filamentous fungi (Aspergillus niger). While the Synadenium glaucescens root proved to be a valuable precursor for producing effective antimicrobial sg-AgNPs, the introduction of sg-AgNPs into WSPs significantly impacted algal chlorophyll-a production and survival of ostracod population. These results shed light on the ecotoxicological risks of sg-AgNPs for WSPs organisms and highlight the suitability of algae and ostracods as model organisms for ecotoxicological studies in WSPs. [ABSTRACT FROM AUTHOR]

The wide-spreading of multidrug resistance poses a significant threat to human and animal health. Although antimicrobial peptides (AMPs) show great potential application, their instability has severely limited their clinical application. Here, self-assembled AMPs composed of multiple modules based on the principle of associating natural marine peptide N6 with ß-sheet-forming peptide were designed. It is noteworthy that one of the designed peptides, FFN could self-assemble into nanoparticles at 35.46 µM and achieve a dynamic transformation from nanoparticles to nanofibers in the presence of bacteria, resulting in a significant increase in stability in trypsin and tissues by 1.72–57.5 times compared to that of N6. Additionally, FFN exhibits a broad spectrum of antibacterial activity against multidrug-resistant (MDR) gram-positive (G+) and gram-negative (G−) bacteria with Minimum inhibitory concentrations (MICs) as low as 2 µM by membrane destruction and complemented by nanofiber capture. In vivo mouse mastitis infection model further confirmed the therapeutic potential and promising biosafety of the self-assembled peptide FFN, which can effectively alleviate mastitis caused by MDR Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and eliminate pathogenic bacteria. In conclusion, the design of peptide-based nanomaterials presents a novel approach for the delivery and clinical translation of AMPs, promoting their application in medicine and animal husbandry. [ABSTRACT FROM AUTHOR]

AbstractIn this context, we designed and synthesized a series of hydrazonal and their related indeno[1,2-b]pyridin-5-one derivatives to investigate their antibacterial and anti-biofilm properties. Several of the synthesized compounds exhibited significant efficacy against all microorganism species tested. Most of the compounds demonstrated favorable results when tested against Gram-positive bacteria. The derivatives 4a, 4f, 6c, and 6f exhibit the highest antimicrobial efficacy, as indicated by their minimum inhibitory concentration (MIC) values ranging from 4 to 512 μg/mL. We conducted additional investigations on 4a, 6c, and 6f for the purpose of examining their synergy using Checkerboard assay. Compound 6c demonstrated a synergistic impact against methicillin-sensitive Staphylococcus aureus (MSSA) and Pseudomonas aeruginosa, while exhibiting moderate synergistic activity against methicillin-resistant Staphylococcus aureus (MRSA). In addition, the simultaneous use of gentamycin with compounds 4a and 6f demonstrates a synergistic impact in fighting against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively. Three chosen compounds were evaluated for their antibiofilm efficacy. Application of 4a, 6c, and 6f effectively reduced the production of biofilms in MRSA, MSSA, and Pseudomonas aeruginosa, resulting in a significant decrease compared to the untreated samples. In addition, ADME and pharmacokinetic analyses were conducted for the three most potent derivatives, namely 4a, 6c, and 6f. Compounds 4a and 6c were subjected to docking in the LasR Quorum-Sensing Receptor, whereas compounds 6c and 6f were docked in the sortase enzyme. [ABSTRACT FROM AUTHOR]

Background: One of the main risks of infection after hematopoietic stem cell transplantation (HSCT) is infection by gram-positive bacteria, including vancomycin-resistant enterococci (VRE). Based on the format of a global review and meta-analysis study, this study aims to investigate the incidence of VRE bloodstream infection (BSI) after HSCT in colonized individuals. Methods: The keywords of the systematic search included vancomycin-resistant enterococci and HSCT. These words were searched in Google Scholar, PubMed/Medline, Scopus, and Web of Science databases from January 1, 2000, to March 1, 2024. Studies that reported the prevalence of vancomycin-resistant enterococci in patients undergoing HSCT were included. The random effects model was used for the meta-analyses. Investigations were conducted according to PRISMA guidelines, and the protocol was registered in PROSPERO: CRD42024543491. Results: Out of 1100 screened papers, 28 were eligible. The random effects model was established to analyze the incidence of VRE BSI after HSCT. The pooled prevalence of co-infection for Allo-HSCT recipients was 3.023 (95% CI, Z-value = -3.5, p-value < 0.0001), and this value for Auto-HSCT recipients was 11.89 (95% CI, Z-value = -2.923, p-value < 0.001). These results showed that the rate of BSI due to vancomycin-resistant enterococcus in Auto-HSCT recipients is higher than Allo-HSCT. Conclusions: The prevalence of vancomycin-resistant enterococci in Auto-HSCT recipients is higher than that of Allo-HSCT, possibly due to colonization of the intestines of these people with vancomycin-resistant enterococci before transplantation. VRE Colonization before transplantation increases the likelihood of post-transplant VRE BSI and other bacterial infections, including Gram-negative. The strains should be analyzed by sequencing before and after HSCT for a more detailed investigation. [ABSTRACT FROM AUTHOR]

Background: Marine actinomycetes, especially Streptomyces, are recognized as excellent producers of diverse and bioactive secondary metabolites on account of the multiplicity of marine habitations and unique ecological conditions, which are yet to be explored in terms of taxonomy, ecology, and functional activity. Isolation, culture and genome analysis of novel species of Streptomyces to explore their potential for discovering bioactive compounds is an important approach in natural product research. Results: A marine actinobacteria, designated strain SCSIO 75703 T, was isolated, and the potential for bioactive natural product discovery was evaluated based on genome mining, compound detection, and antimicrobial activity assays. The phylogenetic, phenotypic and chemotaxonomic analyses indicate that strain SCSIO 75703 T represents a novel species in genus Streptomyces, for which the name Streptomyces sediminicola sp. nov. is proposed. Genome analysis revealed the presence of 25 secondary metabolite biosynthetic gene clusters. The screening for antibacterial activity reveals the potential to produce bioactive metabolites, highlighting its value for in-depth exploration of chemical constituents. Seven compounds (1–7) were separated from the fractions guided by antibacterial activities, including three indole alkaloids (1–3), three polyketide derivatives (4–6), and 4-(dimethylamino)benzoic acid (7). These primarily antibacterial components were identified as anthracimycin (4), 2-epi-anthracimycin (5) and β-rubromycin (6), presenting strong antibacterial activities against Gram-positive bacteria with the MIC value ranged from 0.125 to 16 μg/mL. Additionally,, monaprenylindole A (1) and 3-cyanomethyl-6-prenylindole (2) displayed moderate inhibitory activities against α-glucosidase with the IC50 values of 83.27 and 86.21 μg/mL, respectively. Conclusion: Strain SCSIO 75703 T was isolated from marine sediment and identified as a novel species within the genus Streptomyces. Based on genomic analysis, compounds isolation and bioactivity studies, seven compounds were identified, with anthracimycin and β-rubromycin showing significant biological activity and promising potential for further applications. [ABSTRACT FROM AUTHOR]

Infection of native tissues or implanted devices is common, but clinical diagnosis is frequently difficult and currently available noninvasive tests perform poorly. Immunocompromised individuals (for example transplant recipients, or those with cancer) are at increased risk. No imaging test in clinical use can specifically identify infection, or accurately differentiate bacterial from fungal infections. Commonly used [18F]fluorodeoxyglucose (18FDG) positron emission computed tomography (PET/CT) is sensitive for infection, but limited by poor specificity because increased glucose uptake may also indicate inflammation or malignancy. Furthermore, this tracer provides no indication of the type of infective agent (bacterial, fungal, or parasitic). Imaging tools that directly and specifically target microbial pathogens are highly desirable to improve noninvasive infection diagnosis and localization. A growing field of research is exploring the utility of radiometals and their chelators (siderophores), which are small molecules that bind radiometals and form a stable complex allowing sequestration by microbes. This radiometal-chelator complex can be directed to a specific microbial target in vivo, facilitating anatomical localization by PET or single photon emission computed tomography. Additionally, bifunctional chelators can further conjugate therapeutic molecules (e.g., peptides, antibiotics, antibodies) while still bound to desired radiometals, combining specific imaging with highly targeted antimicrobial therapy. These novel therapeutics may prove a useful complement to the armamentarium in the global fight against antimicrobial resistance. This review will highlight current state of infection imaging diagnostics and their limitations, strategies to develop infection-specific diagnostics, recent advances in radiometal-based chelators for microbial infection imaging, challenges, and future directions to improve targeted diagnostics and/or therapeutics. [ABSTRACT FROM AUTHOR]

Background: Alteration in the etiology of pediatric bloodstream infections (BSIs) and antimicrobial resistance (AMR) is not well known during the Coronavirus disease 2019 (COVID-19) pandemic. This study aimed to investigate the impact of the COVID-19 pandemic on pediatric BSIs and alteration in antimicrobial resistance phenotypes in Gram-positive bacteria. Methods: The frequency of BSIs among children under 18 years old was retrospectively recorded in a tertiary children's hospital in Tehran, Iran from February 2020 to December 2022. The status of COVID-19 infection using reverse transcription polymerase chain reaction, bacteremia/fungemia according to BACTEC 9120 Culture System results, characterization of bacteria using biochemical tests, and antimicrobial susceptibility patterns for Gram-positive bacterial isolates using disk diffusion method were determined. Statistical analysis was done to measure the correlation of COVID-19 infection with BSIs and AMR. Results: Out of 13,345 COVID-19 tests and 4,194 BACTEC blood culture requests, bacteremia/fungemia were confirmed in 10.37% (435/4,194) of the patients who requested both tests simultaneously. The COVID-19 infection was confirmed in 25.3% (110/435) of the patients with bacteremia/fungemia. The infection with characterized Gram-positive bacteria (GPB) and fungi was detected in 32.3% (140/433) and 8.31% (36/433) of the cases, respectively. Coagulase-negative Staphylococcus (CNS, 72, 16.62%), S. aureus (36, 8.3%), and Enterococcus spp. (22, 5%) were among the common isolates. Candida spp. and non-Candida yeasts were detected in 6.7% and 13.4% of the cases, respectively. A positive correlation was shown between the CNS bacteremia and COVID-19 infection (p-value = 0.019). Antibiotic susceptibility testing results showed the highest frequency of resistance to azithromycin among CNS, azithromycin and tetracycline among S. aureus and tetracycline among Enterococcus spp. Methicillin-resistance phenotype in the S. aureus (MRSA) and coagulase-negative Staphylococcus spp. (MR-CNS) was detected in 40% and 61.5% of the strains, respectively and the Enterococci were resistant to vancomycin in 33.3% of the isolates. Conclusion: A decline in the trend of BSIs by GPB and an increase in AMR was shown in children during the COVID-19 pandemic. Increasing antibiotic resistance is a concern; however, chloramphenicol, linezolid, and vancomycin remain active against common causes of GPB-BSIs. [ABSTRACT FROM AUTHOR]

Background: Alterations in upper respiratory microbiomes have been implicated in shaping host health trajectories, including by limiting mucosal pathogen colonization. However, limited comparative studies of respiratory microbiome development and functioning across age groups have been performed. Herein, we perform shotgun metagenomic sequencing paired with pathogen inhibition assays to elucidate differences in nasal and oral microbiome composition and intermicrobial interactions across healthy 24-month-old infant (n = 229) and adult (n = 100) populations. Results: We find that beta diversity of nasal and oral microbiomes varies with age, with nasal microbiomes showing greater population-level variation compared to oral microbiomes. Infant microbiome alpha diversity was significantly lower across nasal samples and higher in oral samples, relative to adults. Accordingly, we demonstrate significant differences in genus- and species-level composition of microbiomes between sites and age groups. Antimicrobial resistome patterns likewise varied across body sites, with oral microbiomes showing higher resistance gene abundance compared to nasal microbiomes. Biosynthetic gene clusters encoding specialized metabolite production were found in higher abundance across infant oral microbiomes, relative to adults. Investigation of pathogen inhibition revealed greater inhibition of gram-negative and gram-positive bacteria by oral commensals, while nasal isolates had higher antifungal activity. Conclusions: In summary, we identify significant differences in the microbial communities inhabiting nasal and oral cavities of healthy infants relative to adults. These findings inform our understanding of the interactions impacting respiratory microbiome composition and functions related to colonization resistance, with important implications for host health across the lifespan. 5XcHcd9N21H4_6hqSTf5-o Video Abstract [ABSTRACT FROM AUTHOR]

Ribavirin and its analogues exhibit an in vitro antiproliferative effect in cancer cells. In this work, we studied the biological activities of a number of alkyl/aryloxymethyl derivatives of ribavirin's aglycon—1,2,4-triazole-3-carboxamide. Alkyl/arylxymethyl derivatives of 1,2,4-triazole-3-carboxamide with substitutions at the fifth or first position of the triazole ring, were synthesized and their antiproliferative and antimicrobial effects were assessed. For both series, the presence of an antiproliferative effect was investigated, and 1-alkyl/aryloxymethyl derivatives were shown an antimicrobial potential against a Gram-positive bacteria Micrococcus luteus and Gram-negative bacterium Pseudomonas aeruginosa. The obtained results showed that the n-decyloxymethyl derivatives induced leukemia cell death at low micromolar concentrations. We confirmed that n-decyloxymethyl derivatives of ribavirin inhibited the cell cycle progression and induced an accumulation of leukemia cells in the subG1-phase. The molecular docking results suggest that alkyl/aryloxymethyl derivatives may act by inhibiting translation initiation, due to interference with eIF4E assembly. The outcome results revealed that active derivatives (1- or 5-n-decyloxymethyl-1,2,4-triazole-3-carboxamides) can be considered as a lead compound for anticancer treatments. [ABSTRACT FROM AUTHOR]

A series of new isatin-3-hydrazones bearing different ammonium fragments was synthesized by a simple and easy work-up reaction of Girard's reagents analogs with 1-(3,5-di-tert-butyl-4-hydroxybenzyl)isatin. All derivatives have been shown to have antioxidant properties. In terms of bactericidal activity against gram-positive bacteria, including methicillin-resistant strains of Staphylococcus aureus, the best compounds are 3a, 3e, and 3m, bearing octyl, acetal, and brucine ammonium centers, respectively. In addition, brucine and quinine derivatives 3l, and 3j exhibit platelet antiaggregation activity at the level of acetylsalicylic acid, and this series of isatin derivatives does not adversely affect the hemostasis system as a whole. Thus, all the obtained results can lay the groundwork for future pharmaceutical developments for the creation of effective antibacterial drugs with reduced systemic toxicity due to the presence of antioxidant properties. [ABSTRACT FROM AUTHOR]

Bacterial infections are rapidly evolving and are among the greatest threats to human health. Infectious diseases from antibiotic-resistant bacteria rank as the fourth leading cause of preventable death. A multi-modality antibacterial strategy has become an emerging and attractive method to deal with bacterial drug resistance. Herein, tunable phase-change materials@Prussian blue microparticles (PCM@PB MPs) were designed by gas-shearing microfluidics, which show the synergistic effect of antibiotic-, photothermal- and chemodynamic-induced antibacterial properties. MPs exhibit significant antibacterial activity and biofilm-clearing abilities against S. aureus and E. coli, which represent Gram-negative and Gram-positive bacteria. This research explored the use of MPs as a tri-modality antibacterial agent and provided valuable insights into their mechanism against bacterial cells. Furthermore, by combining the temperature-responsive properties of PCM with the photothermal properties of PB, a reliable vehicle with triggered drug release was designed, potentially fitting a niche in many applications in the coming years. [ABSTRACT FROM AUTHOR]

Alpha-helical AMPs' specific targeting on both cell wall and cytoplasmic membrane of Gram-positive S. aureus , and their obvious behaviour of inducing membrane microphase-separation in bacterial killing. [Display omitted] Multidrug resistance (MDR) is a rising threat to global health because the number of essential antibiotics used for treating MDR infections is increasingly compromised. In this work we report a group of new amphiphilic peptides (AMPs) derived from the well-studied G 3 (G(IIKK) 3 I-NH 2) to fight infections from Gram-positive bacteria including susceptible Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA), focusing on membrane interactions. Time-dependent killing experiments revealed that substitutions of II by WW (GWK), II by FF (GFK) and KK by RR (GIR) resulted in improved bactericidal efficiencies compared to G 3 (GIK) on both S. aureus and MRSA, with the order of GWK > GIR > GFK > GIK. Electronic microscopy imaging revealed structural disruptions of AMP binding to bacterial cell walls. Fluorescence assays including AMP binding to anionic lipoteichoic acids (LTA) in cell-free and cell systems indicated concentration and time-dependent membrane destabilization associated with bacterial killing. Furthermore, AMP's binding to anionic plasma membrane via similar fluorescence assays revealed a different extent of membrane depolarization and leakage. These observations were supported by the penetration of AMPs into the LTA barrier and the subsequent structural compromise to the cytoplasmic membrane as revealed from SANS (small angle neutron scattering). Both experiments and molecular dynamics (MD) simulations revealed that GWK and GIR could make the membrane more rigid but less effective in diffusive efficiency than GIK and GFK through forming intramembrane peptide nanoaggregates associated with hydrophobic mismatch and formation of fluidic and rigid patches. The reported peptide-aggregate-induced phase-separation emerged as a crucial factor in accelerated membrane disintegration and fast bacterial killing. This work has demonstrated the importance of membrane interactions to the development of more effective AMPs and the relevance of the approaches as reported in assisting this area of research. [ABSTRACT FROM AUTHOR]

Background: Although the etiology of aneurysms remains elusive, recent advances in high-throughput sequencing technology and ongoing human microbiome investigations suggest a potential link between microbiome composition and the onset of various human diseases. Objective: This study aimed to utilize high-throughput 16 S rRNA gene sequencing to analyze the oral flora bacterial profiles of individuals, comparing patients with intracranial aneurysms to a healthy control group. Importantly, we sought to identify differences in the oral microbiota and offer novel insights and methods for early diagnosis and identification of intracranial aneurysms. Method: Saliva samples were collected from 60 patients with cerebral aneurysms (case group) and 130 healthy individuals (control group). The V3-V4 region of the bacterial 16 S rRNA gene was amplified and sequenced using the HiSeq high-throughput sequencing platform to establish the bacterial profile. Sequencing data were analyzed using QIIME2 and Metastats software to compare composition differences and relative abundance at the phylum and genus levels in the oral microbiota of the two groups. Results: Significant differences in oral microbiota composition were observed between patients in the case and control groups (P < 0.05). Genus-level identification highlighted key positions occupied by Eubacterium, Saccharimonadaceae, Rothia, Gemella, Streptococcus, Lactobacillales, Phocaeicola, Bacteroides, Saccharimonadales, and Abiotrophia. Conclusion: This study revealed noteworthy distinctions in the composition, abundance, and diversity of oral microbiota between intracranial aneurysm patients and healthy controls. These disparities suggest a potential correlation between oral microbiota and the development of intracranial aneurysms, offering new avenues for early diagnosis and intervention. However, limitations such as a small sample size, lack of prospective design, and absence of causal inference warrant further validation and exploration. [ABSTRACT FROM AUTHOR]

Salvia dumetorum essential oil (SDEO) was obtained using a Clevenger apparatus by hydrodistillation approach. The chemical composition of the essential oil was determined by GC-MS analysis. In this study SDEO was screened for its antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Candida albicans and the amount of biofilm formed by Streptococcus mutans bacteria. For the first time the chemical composition of SDEO growing in Central Kazakhstan was established. The results obtained from GC-MS showed the predominance of sesquiterpenoids (54.15%). The antibacterial study results showed that SDEO exhibited strong antibacterial activity against B. subtilis and S. aureus in vitro and also demonstrated an inhibitory effect on S. mutans biofilm formation on 1% sucrose medium. During the study, no antibacterial activity was detected against E. coli and C. albicans. These results demonstrated that SDEO can be used in the development of new antibacterial and anti-caries therapeutic dental products. [ABSTRACT FROM AUTHOR]

A copper-based metal-organic framework named NH2-Cu-MOF has been synthesized and utilized as an effective broad-spectrum antimicrobial material in this article. The obtained NH2-Cu-MOF exhibits satisfying antibacterial activity against both gram-positive bacteria (S. aureus and S. epidermidis) and gram-negative bacteria (E. coli and K. peneumoniae). Additionally, the biocompatibility of this NH2-Cu-MOF has been validated through animal studies, showing no significant adverse effects, thereby confirming its high biocompatibility. These findings prove that NH2-Cu-MOF has positive effects upon the treatment of bacteria-infected wounds, which holds great potential to be applied in biochemistry field. [ABSTRACT FROM AUTHOR]

This study aimed to optimize the production of carotenoid pigments from Micrococcus luteus (ATCC 9341) through the statistical screening of media components and the characterization of antimicrobial, antioxidant, cytogenetic and cytotoxic activities. A BOX-Behnken design was used to assess the effects of whey concentration, inoculum size, pH, temperature, and agitation speed on carotenoid yield. The optimum combination increased production to 2.19 g/L, with a productivity of 0.045 g L-1 h−1 and a productivity yield of 0.644 g/g, as confirmed by an observed carotene production of 2.19 g/L. The final response surface model fitting the data had an R2 of 0.9461. High-performance liquid chromatography (HPLC) analysis identified 12 carotenoid pigment compounds produced by M. luteus. The extracts displayed moderate antimicrobial efficacy against Gram-positive bacteria such as Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 6538), and E. faecalis (ATCC 19433), with inhibition zone diameters (IZD) of 29.0, 14.0, and 37.0 mm, respectively, at 1000 μg/mL. However, its effectiveness against Gram-negative bacteria is limited. In comparison, tetracycline exhibited greater antimicrobial potency. The IC50 value of carotenoids was used to indicate the antioxidant activity. IC50 value from the DPPH assay was 152.80 mg/100mL. An IC50 cytotoxicity value greater than 300 μg/mL was found against normal mouse liver cells, with over 68% cell viability even at 300 μg/mL, indicating low toxicity. Histological structure studies revealed normal myocardial muscle tissue, lung tissue, and kidney tissue sections, whereas liver tissue sections revealed ballooning degeneration of hepatocytes and disorganization of hepatic cords. Cytogenetic parameters revealed that the carotene treatment group had a mitotic index (70%) lower than that of the control but higher than that of the positive control, mitomycin, and did not substantially increase numerical (1.2%) or structural aberrations compared with those of the control, suggesting a lack of genotoxic effects under the experimental conditions. In conclusion, optimized culture conditions enhanced carotenoid yields from M. luteus, and the extracts displayed promising bioactivity as moderate antibiotics against certain gram-positive bacteria and as antioxidants. The high IC50 values demonstrate biosafety. Overall, this bioprocess for enhanced carotenoid production coupled with bioactivity profiling and low cytotoxicity support the application of M. luteus carotenoids. [ABSTRACT FROM AUTHOR]

The auto-combustion method synthesized CuO NPs and Ag/CuO NPs. The Ag/CuO NPs were analyzed using Fourier-transform infrared, X-ray diffraction, scanning electron microscope, and Energy-dispersive X-ray spectroscopy instrumental analyses. The energy band gap, as determined by DRS properties, decreases from 3.82 to 3.50 eV for pure CuO and 10% Ag/CuO NPs, respectively. The photodegradation efficiency of Rhodamine-B & Carmine by 10% Ag/CuO NPs was nearly 98.9 and 97.8%, respectively. Antimicrobial trials revealed that the antimicrobial efficacy of Ag/CuO NPs at several dosages (20, 40, 60, 80, 100, and 120 µg/mL) against human pathogens was initially assessed using the agar well-diffusion method, and then the broth dilution method. Noticeably, the minimum inhibitory concentration of Ag/CuO NPs for all pathogens ranged from 100 to 120 µg/ml, was determined. Generally, the observed minimum microbicide concentration has a wide range of Ag/CuO NPs doses, ranging from 150 to 300 µg/ml, which helps kill (99.99%) all tested pathogenic cells. The largest relative inhibitory activities (%) were recorded against Escherichia coli (81.45 ± 1.39) at 120 g/mL of Ag/CuO NPs and 100 μg/mL (80.43 ± 0.59), followed by 80 µg/mL (72.33 ± 0.82). Additionally, the lowest relative inhibitory activities (%) were monitored versus fungal cells and Gram-positive bacteria at 120 µg/mL of Ag/CuO NPs as 52.17 ± 1.49 and 53.42 ± 1.71; respectively. [ABSTRACT FROM AUTHOR]

Camellia pleurocarpa (Gagnep.) Sealy, a species of yellow camellia indigenous to Vietnam, was investigated for its essential oil properties in this study. Hydrodistillation of its leaves yielded a complex mixture rich in sesquiterpenes and diterpenes. Chemical analysis identified 50 constituents, with notable compounds including spathulenol (13.26%), phytol (9.94%), and α-selinene (5.34%). The essential oil exhibited significant antimicrobial activity against three Gram-positive bacteria Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus; one Gram-negative bacterium Pseudomonas aeruginosa; and one yeast Candida albicans, with minimum inhibitory concentration (MIC) values ranging from 16 to 32 μg/mL and half-maximal inhibitory concentration (IC50) values ranging from 7.26 to 16.23 μg/mL. Furthermore, it demonstrated larvicidal potential against Aedes aegypti and Culex quinquefasciatus mosquitoes, with LC50 values ranging from 13.49 to 28.95 μg/mL and LC90 values ranging from 28.29 to 53.24 μg/mL. These findings underscore the promising antimicrobial and mosquito larvicidal properties of C. pleurocarpa essential oil, suggesting its potential as a natural alternative in combating microbial infections and controlling mosquito-borne diseases. This study represents the first comprehensive report on the chemical compositions and bioactivities of C. pleurocarpa essential oil. [ABSTRACT FROM AUTHOR]

The rates of mortality and morbidity from treatment failures have increased due to microorganisms' growing resistance to antimicrobial medicines, signaling a severe hazard in the near future. Copper oxide (CuO) nanoparticles (NPs) were prepared using the laser penetration in water (LPW) method, which is regarded as an innovative and effective technique for producing a wide range of nanomaterials. The physical properties of the prepared NPs were studied by identifying them by dynamic light scattering (DLS), UV–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and energy-dispersive X-ray analysis (EDX). The absorption spectrum showed two peaks, one with a modest intensity at 650 nm and the other at 280 nm. In the optical characteristics study, the band gaps estimated for the CuO NPs are 3.6 eV. XRD shows the prepared CuO NPs have a polycrystalline structure with a pre-indication particle size of approximately 35 nm. The DLS results showed that the synthesized CuO nanoparticle has 35.19 ± 12.82 nm in size and − 21.3 ± 6.56 in charge. FESEM image shows that CuO NPs have a homogeneous distributed spherical shape with some accumulation NPs in a cauliflower-like shape. Antibacterial activity of the prepared nanoparticles was tested against two types of bacterial strains, gram-positive bacteria Staphylococcus aureus (S. aureus) and gram-negative bacteria Escherichia coli (E. coli), isolated from the infected wounds. AgNO3 was used as a control to compare with different concentrations of CuO NPs. The result indicated the antibacterial activity of CuO NPs was concentration-dependent and exceeded the antibacterial activity of the control agent (AgNO3). At CuO NPs, the maximum concentration used was 200 µg/ml, and the inhibition zone was 16.5 mm and 15 mm for E. coli and S. aureus, respectively. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus poses a significant threat in both community and hospital settings due to its infective and pathogenic nature combined with its ability to resist the action of chemotherapeutic agents. Methicillin-resistant S. aureus (MRSA) represents a critical challenge. Metal-chelating thiosemicarbazones (TSCs) have shown promise in combating MRSA and while previous studies hinted at the antimicrobial potential of TSCs, their mechanisms of action against MRSA are still under investigation. We screened a chemical library for anti-staphylococcal compounds and identified a potent molecule named R91 that contained the NNSN structural motif found within TSCs. We identified that R91 and several structural analogs exhibited antimicrobial activity against numerous S. aureus isolates as well as other Gram-positive bacteria. RNAseq analysis revealed that R91 induces copper and oxidative stress responses. Checkerboard assays demonstrated synergy of R91 with copper, nickel, and zinc. Mutation of the SrrAB two-component regulatory system sensitizes S. aureus to R91 killing, further linking the oxidative stress response to R91 resistance. Moreover, R91 was found to induce hydrogen peroxide production, which contributed to its antimicrobial activity. Remarkably, no mutants with elevated R91 resistance were identified, despite extensive attempts. We further demonstrate that R91 can be used to effectively treat an intracellular reservoir of S. aureus in cell culture and can reduce bacterial burdens in a murine skin infection model. Combined, these data position R91 as a potent TSC effective against MRSA and other Gram-positive bacteria, with implications for future therapeutic development. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance (AMR) refers to the capacity of bacteria to resist the impact of antibiotics, emerging as a significant global health concern. To discover novel antibacterial agents, the isolation and elucidation of compounds from leaf and twig extracts of Uvaria wrayi (King) L.L. Zhou, Y.C.F. Su & R.M.K. Saunders were investigated for the first time. 9 known compounds were performed and categorized as polyoxygenated cyclohexenes (1-3), seco-cyclohexenes (4), acrylamide derivatives (5,6), and aristolactam alkaloids (7-9). All isolated compounds were evaluated for their antimicrobial activities against 5 Gram-positive bacteria, including Staphylococcus aureus (TISTR 746), Staphylococcus epidermidis (DMST 15505), Methicillin-resistant Staphylococcus aureus (MRSA) (NPRC 001R), Cutibacterium acnes (formerly Propionibacterium acnes) (DMST 14916), and Streptococcus mutans (DMST 18777/ATCC 25175T). 2 Gram-negative bacteria, Shigella flexneri (DMST 4423) and Salmonella enterica ser. typhimurium (TISTR 2519) were evaluated. Most of the isolated compounds displayed moderate antimicrobial activity with a MIC value of 64 µg/mL, except compounds 1,9 showed antibacterial against MRSA with a MIC value of 128 µg/mL. Compounds 2-9 exhibited antimicrobial activity against C. acnes (DMST 14916) with a MIC value of 32 µg/mL. Compounds 1-3, 6, and 7 also responded to inhibit C. acnes with the same MBC value of 128 µg/mL. This exploration holds promise for advancing our understanding of potential antibacterial compounds within U. wrayi and addressing the challenges posed by antimicrobial resistance. [ABSTRACT FROM AUTHOR]

Data on irradiation of poly(L-lactide) (PLLA) based active packaging is still limited. Therefore, effect of γ-irradiation on neat PLLA and active packaging with oligohexamethylene guanidine hydrochloride (OHMG·HCl) has been studied. Combined use of irradiation and active packaging technology is promising approach to maintain food safety and prolong shelf life. It has been found that regardless of the OHMG·HCl content PLLA undergoes chain scission during irradiation and this process becomes less pronounced at doses higher than 50 kGy. Slight racemization of PLLA during exposure has been observed using polarimetry and 13C NMR spectroscopy. Mechanical properties of films have been examined. Biocide addition led to a 30% decrease in films elongation at break. Irradiation either caused elongation decrease. Dose of 50 kGy and higher made PLLA active films brittle. Multiple melting behavior of irradiated PLLA has been analyzed by differential scanning calorimetry. Fraction of crystals with higher melting temperature rose with dose. Possible reason for this phenomenon is formation of α′ form with less ordered chain packaging that recrystallizes during heating. The biocide addition has not affected this process. Furthermore, in vitro antimicrobial test has shown efficacy of films with 2 wt.% of OHMG·HCl against gram-negative, gram-positive bacteria and fungi. [ABSTRACT FROM AUTHOR]

Purpose: One highlighted pathogenesis mechanism of diseases is the negative impact of pro-inflammatory diets (PD) on the gut microbiome. This systematic review aimed to study the link between dietary inflammatory index (DII), as an indicator of PD, and gut microbiome. Methods: A systematic search was done in PubMed and Scopus, adhering to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis. The assessment of the included studies' quality was performed using the critical appraisal checklist from the Joanna Briggs Institute. Results: Ten articles were included eight cross-sectional, one case-control, and, one cohort study. Seven and three included articles reported a weak and moderate relationship between gut microbiome and DII scores, respectively. DII scores were linked to variety in microbiome composition and diversity/richness. More importantly, anti-inflammatory diets as measured by lower DII scores were linked to a more desirable gut microbiome profile. Prevotella stercorea, Veillonella rogosae, Morganella morganii, Ruminococcus torques, Eubacterium nodatum, Alistipes intestine, Clostridium leptum, Morganellaceae family, Enterobacteriaceae family, and, Bacteroides thetaiotaomicron were related to higher DII scores. While, Butyrate-producing bacteria such as Ruminococcaceae and Lachnospiraceae families, Faecalibacterium prausnitzii, and Akkermansia muciniphila were related to lower DII scores. Conclusion: An anti-inflammatory diet, as measured by a lower DII score, might be linked to variations in the composition and variety of the microbiome. Therefore, the DII score could be useful in microbiota research, however, this possibility needs to be investigated more precisely in future studies. [ABSTRACT FROM AUTHOR]

Skin homeostasis relies on a delicate balance between host proteases and protease inhibitors along with those secreted from microbial communities, as disruption to this harmony contributes to the pathogenesis of inflammatory skin disorders, including atopic dermatitis and Netherton's syndrome. In addition to being a prominent cause of skin and soft tissue infections, the gram-positive bacterium Staphylococcus aureus is a key player in inflammatory skin conditions due to its array of 10 secreted proteases. Herein we review how S. aureus proteases augment the development of inflammation in skin disorders. These mechanisms include degradation of skin barrier integrity, immune dysregulation and pruritis, and impairment of host defenses. Delineating the diverse roles of S. aureus proteases has the potential to reveal novel therapeutic strategies, such as inhibitors of proteases or their cognate target, as well as neutralizing vaccines to alleviate the burden of inflammatory skin disorders in patients. [ABSTRACT FROM AUTHOR]

Wine production is one of the most important agricultural activities. The winemaking process generates a considerable volume of different residues characterized as by-products, such as pomace, seeds, stems, and skins. By-products are rich in polyphenols with antioxidant and antibacterial properties and may act as bacteriostatic or bactericidal agents against food-borne pathogens, improving food safety by enhancing antibiotic efficacy and reducing bacterial resistance. The aim of this study was to evaluate the phenolic composition and antioxidant activity of grape components (skins, seeds, and stems) from three red grape varieties (Periquita, Gamay, and Donzelinho Tinto) and determine their antibacterial activity against antibiotic-resistant bacteria, including Escherichia coli in food-producing animals and Listeria monocytogenes from food products and food-related environments. Ten phenolic compounds were quantified in these red grape varieties, with specific compounds found in different parts of the grape, including phenolic acids and flavonoids. Flavonoids are abundant in seeds and stems, malvidin-3-O-glucoside being the main anthocyanin in skins. The ethanolic extract from the seeds showed in vitro concentration-dependent activity against reactive species like •NO and O2•−. Gamay extract was the most effective, followed by Donzelinho Tinto and Periquita. Extracts showed varying antibacterial activity against Gram-positive and Gram-negative bacteria, with stronger effects on Gram-positive bacteria. L. monocytogenes was more susceptible, while E. coli was limited to three strains. Seeds exhibited the strongest antibacterial activity, followed by stems. The results of our study provide evidence of the potential of grape by-products, particularly seeds, as sources of bioactive compounds with antioxidant and antibacterial properties, offering promising avenues for enhancing food safety and combating antibiotic resistance in food production and related environments. [ABSTRACT FROM AUTHOR]

Today, there is a continuous worldwide battle against antimicrobial resistance (AMR) and that includes vancomycin-resistant enterococci (VRE). Methods that can adequately and quickly detect transmission chains in outbreaks are needed to trace and manage this problem fast and cost-effectively. In this study, DNA-microarray-based technology was developed for this purpose. It commenced with the bioinformatic design of specific oligonucleotide sequences to obtain amplification primers and hybridization probes. Microarrays were manufactured using these synthesized oligonucleotides. A highly parallel and stringent labeling and hybridization protocol was developed and employed using isolated genomic DNA from previously sequenced (referenced) clinical VRE strains for optimal sensitivity and specificity. Microarray results showed the detection of virulence, resistance, and species-specific genes in the VRE strains. Theoretical predictions of the microarray results were also derived from the sequences of the same VRE strain and were compared to array results while optimizing protocols until the microarray result and theoretical predictions were a match. The study concludes that DNA microarray technology can be used to quickly, accurately, and economically detect specifically and massively parallel target genes in enterococci. [ABSTRACT FROM AUTHOR]

Phage φ29 and related bacteriophages are currently the smallest known tailed viruses infecting various representatives of both Gram-positive and Gram-negative bacteria. They are characterised by genomic content features and distinctive properties that are unique among known tailed phages; their characteristics include protein primer-driven replication and a packaging process characteristic of this group. Searches conducted using public genomic databases revealed in excess of 2000 entries, including bacteriophages, phage plasmids and sequences identified as being archaeal that share the characteristic features of phage φ29. An analysis of predicted proteins, however, indicated that the metagenomic sequences attributed as archaeal appear to be misclassified and belong to bacteriophages. An analysis of the translated polypeptides of major capsid proteins (MCPs) of φ29-related phages indicated the dissimilarity of MCP sequences to those of almost all other known Caudoviricetes groups and a possible distant relationship to MCPs of T7-like (Autographiviridae) phages. Sequence searches conducted using HMM revealed the relatedness between the main structural proteins of φ29-like phages and an unusual lactococcal phage, KSY1 (Chopinvirus KSY1), whose genome contains two genes of RNA polymerase that are similar to the RNA polymerases of phages of the Autographiviridae and Schitoviridae (N4-like) families. An analysis of the tail tube proteins of φ29-like phages indicated their dissimilarity of the lower collar protein to tail proteins of all other viral groups, but revealed its possible distant relatedness with proteins of toxin translocation complexes. The combination of the unique features and distinctive origin of φ29-related phages suggests the categorisation of this vast group in a new order or as a new taxon of a higher rank. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are short, usually cationic peptides with an amphiphilic structure, which allows them to easily bind and interact with the cellular membranes of viruses, bacteria, fungi, and other pathogens. Bacterial AMPs, or bacteriocins, can be produced from Gram-negative and Gram-positive bacteria via ribosomal synthesis to eliminate competing organisms. Bacterial AMPs are vital in addressing the increasing antibiotic resistance of various pathogens, potentially serving as an alternative to ineffective antibiotics. Bacteriocins have a narrow spectrum of action, making them highly specific antibacterial compounds that target particular bacterial pathogens. This review covers the two main groups of bacteriocins produced by Gram-negative and Gram-positive bacteria, their modes of action, classification, sources of positive effects they can play on the human body, and their limitations and future perspectives as an alternative to antibiotics. [ABSTRACT FROM AUTHOR]

In order to control pathogenic microorganisms, three polymer compositions were prepared and tested. First, a water-soluble positively charged polycomplex was synthesized via the electrostatic binding of anionic polyacrylic acid to an excess of polyethylenimine to enhance the biocidal activity of the polycation. Second, an aqueous solution of AgNO3 was added to the polycomplex, thus forming a ternary polycation-polyanion-Ag1+ complex with an additional antimicrobial effect. Third, the resulting ternary complex was subjected to UV irradiation, which ensured the conversion of Ag1+ ions into Ag nanoparticles ranging in size mainly from 10 to 20 nm. Aqueous solutions of the polymer compositions were added to suspensions of the Gram-positive bacteria S. aureus and the Gram-negative bacteria P. aeruginosa, with the following main results: (a) Upon the addition of the binary polycomplex, 30% or more of the cells survived after 20 h. (b) The ternary complex killed S. aureus bacteria but was ineffective against P. aeruginosa bacteria. (c) When the ternary complex with Ag nanoparticles was added, the percentage of surviving cells of both types did not exceed 0.03%. The obtained results are valuable for the development of antibacterial formulations. [ABSTRACT FROM AUTHOR]

The colonization of microbes and the resulting formation of biofilms on dental implants are significant contributors to peri-implantitis and the failure of these implants. The aim of the research was to analyze the impact of density and depth of laser texturing of the Ti-6Al-7Nb alloy surface on the colonization of selected microorganisms and biofilm formation. Standard strains of Gram-negative and Gram-positive bacteria and yeasts from the American Type Culture Collection—ATCC—were used to demonstrate the ability to form single-species biofilms in vitro. The study evaluated three types of titanium samples with different texture density and depth. The colonization and biofilm formation abilities of the tested microorganisms were assessed. The obtained results were subjected to statistical analysis. Among the analyzed strains, L. rhamnosus showed the highest colonization of the tested surfaces. It was found that there is no relationship between the texture parameters and the number of colony-forming units (CFU/mL) for C. albicans, S. mutans, and L. rhamnosus. For the F. nucleatum strain, it was shown that the number of colony-forming bacteria is related to the texture density. [ABSTRACT FROM AUTHOR]

Periodontitis and caries, while seemingly innocuous medical conditions, actually pose significant challenges because of their potential etiology with far more serious conditions. Efficacious treatment is hindered by bacterial antibiotic resistance. Standard AgNPs are ineffective against periodontal anaerobic bacteria, because they require oxidative dissolution to release Ag+ ions, which are the actual antimicrobial agents, but oxidation is not possible under anaerobic conditions. Prior studies on Ag-based periodontal antimicrobial materials either did not confirm a silver oxidation state or did not use strictly anaerobic growth media or both, causing spurious antimicrobial efficacy estimates. Here, we prove that silver ion-doped hydroxyapatite nanoparticles (AgHAp NPs) synthesized at various pHs contain an Ag+ oxidation state and directly release Ag+ even in a strictly anerobic medium. Thus, these AgHAp NPs exhibit direct antimicrobial activity against the fastidious anaerobic Gram-negative periodontal bacterium Fusobacterium nucleatum (F. nucleatum) and against caries-causing aerobic, Gram-positive bacterium Streptococcus mutans (S. mutans). The synthesis pH (6–11) correlates inversely with the Ag+ content (4.5–0.45 wt %) of AgHAp NPs and, hence, with antimicrobial efficacy, thus providing tunable efficacy for the target application. AgHAp NPs had greater antimicrobial efficacy than Ag0-containing AgNPs and were less cytotoxic to the mouse fibroblast L929 cell line. Thus, AgHAp NPs (especially AgHAp7) are superior to AgNPs as effective, broad-spectrum, biocompatible antimicrobials against both anaerobic periodontal and aerobic dental bacteria. AgHAp NP synthesis is also inexpensive and scalable, which are significant factors for treating large global populations of indigent people affected by periodontitis and dental caries. [ABSTRACT FROM AUTHOR]

Objective: The most comprehensive collection of imine was synthesized via a simple, efficient, economical, and rapid method via Schiff base formation. Methods: ((E)-1,5-dimethyl-2-phenyl-4-(((2-phenylimidazo[1,2-a]pyridine-3-yl)methylene)amino)-1,2-dihydro-3H-pyrazol-3-one and their derivatives are synthesized using 4-aminoantipyrine and some substituted 2-phenylimidazo[1,2-a]pyridine-3-carbaldehyde derivatives (SB01) to (SB10). Results and Discussion: The newly synthesized molecules were confirmed using various analytical techniques MS, FT-IR, 1H, and 13C NMR spectrometric analyses. Newly synthesized imidazo[1,2-a]pyridine compounds undergo their biological evaluation with Gram-positive and Gram-negative bacteria as well as antifungal. Conclusions: (SB10), (SB07), (SB05), and (SB01) molecules show good, moderate, and excellent results against tested drugs. [ABSTRACT FROM AUTHOR]

The chemical composition, antimicrobial, and antibiofilm activities of the essential oil from the fruits of Turkish endemic Prangos hulusii were studied. Essential oil was analyzed by GC and GC/MS. Thirty-nine compounds were identified, which represent 98.6% of the total composition of the essential oil. Monoterpene hydrocarbons and sesquiterpene hydrocarbons were the most represented classes of volatiles with 49.8% and 21.0%, respectively. The main constituents of the essential oil were (E)-methyl cinnamate (22.9%), α-phellandrene (13.8%), and (E)-β-ocimene (12.9%). (E)-methyl cinnamate was detected in Prangos spp. for the first time. Antimicrobial activities against three Gram-positive bacteria, three Gram-negative bacteria, and three yeast strains were evaluated using disk diffusion test and microdilution method. Antibiofilm experiments were done by spectrophotometric microplate method and the results of Staphylococcus aureus, Escherichia coli, and Candida albicans were visualized via scanning electron microscopy. The essential oil had an antimicrobial effect and showed an antibiofilm effect on these strains. [ABSTRACT FROM AUTHOR]

Recent advances in sampling and -omics techniques allow a better characterization of the taxonomic composition and functional potential of the small intestinal microbiota (SIM). The SIM is composed of a core microbiota present in high abundance along the entire small intestinal tract complemented with a set of segment-specific taxa. The SIM plays an essential role in carbohydrate degradation, amino acid metabolism, lipid absorption, and micronutrient metabolism. Small intestinal bacterial overgrowth can be classified in two subgroups, namely small intestinal oral bacterial overgrowth (SIOBO) characterized by an overgrowth of oropharyngeal Gram-positive bacteria, and coliform small intestinal bacterial overgrowth (SIBO) characterized by an overgrowth of Enterobacteriaceae such as Escherichia or Klebsiella. SIOBO may contribute to environmental enteric dysfunction and linear growth delay. The small intestinal microbiota (SIM) is essential for gastrointestinal health, influencing digestion, immune modulation, and nutrient metabolism. Unlike the colonic microbiota, the SIM has been poorly characterized due to sampling challenges and ethical considerations. Current evidence suggests that the SIM consists of five core genera and additional segment-specific taxa. These bacteria closely interact with the human host, regulating nutrient absorption and metabolism. Recent work suggests the presence of two forms of small intestinal bacterial overgrowth, one dominated by oral bacteria (SIOBO) and a second dominated by coliform bacteria. Less invasive sampling techniques, omics approaches, and mechanistic studies will allow a more comprehensive understanding of the SIM, paving the way for interventions engineering the SIM towards better health. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis and characterization of new diamines with carbazole and imidazole pendant groups, leading to the development of polyamides and polyimides. The polyamides were synthesized by reacting diamines with carboxylic acids using polyamidation and phosphorylation techniques, while polyimides were prepared by combining diamines and dianhydrides. FT–IR and 1H-NMR analyses were used for comprehensive structural elucidation of diamine, polyamides, and polyimides. The polyamides and polyimides with inherent viscosities ranging from 0.48 to 0.64 dL/g showed notable thermal stability. The T10% weight loss values were between 287 and 340 °C for polyamides and 321–381 °C for polyimides. The percentage of char residue varied between 33 and 56% at 700 °C. Additionally, the maximum emission wavelengths of polymers ranged from 410 to 436 nm. The presence of bulky carbazole and imidazole pendant groups facilitated the good solubility of the polymers in common organic solvents. The antibacterial properties of synthesized polyamides and polyimides against both Gram-negative and Gram-positive bacteria and fungi were investigated. [ABSTRACT FROM AUTHOR]

Iron is one of the essential nutrients for almost all microorganisms. Under iron-limited conditions, bacteria can secrete siderophores to the outside world to absorb iron for survival. This process requires the coordinated action of energy-transducing proteins, transporters, and receptors. The spoilage factors of some spoilage bacteria and the pathogenic mechanism of pathogenic bacteria are also closely related to siderophores. Meanwhile, some siderophores have also gradually evolved toward beneficial aspects. First, a variety of siderophores are classified into three aspects. In addition, representative iron uptake systems of Gram-negative and Gram-positive bacteria are described in detail to understand the common and specific pathways of iron uptake by various bacteria. In particular, the causes of siderophore-induced bacterial pathogenicity and the methods and mechanisms of inhibiting bacterial iron absorption under the involvement of siderophores are presented. Then, the application of siderophores in the food sector is mainly discussed, such as improving the food quality of dairy products and meat, inhibiting the attack of pathogenic bacteria on food, improving the plant growth environment, and promoting plant growth. Finally, this review highlights the unresolved fate of siderophores in the iron uptake system and emphasizes further development of siderophore-based substitutes for traditional drugs, new antibiotic-resistance drugs, and vaccines in the food and health sectors. [ABSTRACT FROM AUTHOR]

The bacterium Bacillus subtilis is a widely used study model and industrial workhorse organism that belongs to the group of gram-positive bacteria. In this study, we report the analysis of a newly sequenced complete genome of B. subtilis strain SRCM117797 along with a comparative genomics of a large collection of B. subtilis strain genomes. B. subtilis strain SRCM117797 has 4,255,638 bp long chromosome with 43.4% GC content and high coding sequence association with macromolecules, metabolism, and phage genes. Genomic diversity analysis of 232 B. subtilis strains resulted in the identification of eight clusters and three singletons. Of 147 B. subtilis strains included, 89.12% had strain-specific genes, of which 6.75% encoded strain-specific insertion sequence family transposases. Our analysis showed a potential role of strain-specific insertion sequence family transposases in intra-cellular accumulation of strain-specific genes. Furthermore, the chromosomal layout of the core genes was biased: overrepresented on the upper half (closer to the origin of replication) of the chromosome, which may explain the fast-growing characteristics of B. subtilis. Overall, the study provides a complete genome sequence of B. subtilis strain SRCM117797, show an extensive genomic diversity of B. subtilis strains and insights into strain diversification mechanism and non-random chromosomal layout of core genes. [ABSTRACT FROM AUTHOR]

Gram-positive bacteria are frequently resistant to empirical beta‐lactams in febrile neutropenic patients with cancer. As microbiology and antibiotic susceptibility changes, we reevaluated the risk factors for resistant Gram-positive bacteremia in febrile neutropenic patients with cancer. Episodes of bacteremic febrile neutropenia in Seoul National University Hospital from July 2019 to June 2022 were reviewed. Resistant Gram-positive bacteria were defined as a pathogen susceptible only to glycopeptide or linezolid in vitro (e.g., methicillin-resistant staphylococci, penicillin-resistant viridans streptococci, and ampicillin-resistant enterococci). Episodes were compared to identify independent risk factors for resistant Gram-positive bacteremia. Of 225 episodes, 78 (34.7%) involved resistant Gram-positive bacteremia. Multivariate analysis revealed that breakthrough bacteremia while being administered antibiotics (adjusted odds ratio [aOR], 6.794; 95% confidence interval [95% CI], 3.130–14.749; P < 0.001) and catheter-related infection (aOR 4.039, 95% CI 1.366–11.946; P = 0.012) were associated with resistant Gram-positive bacteremia. Chronic liver disease (aOR 0.231, 95% CI 0.059–0.905; P = 0.035) and hypotension at bacteremia (aOR 0.454, 95% CI 0.218–0.945; P = 0.035) were inversely associated with resistant Gram-positive bacteremia. Resistant Gram-positive bacteria should be considered in breakthrough bacteremia and catheter-related infection in febrile neutropenic patients with cancer. [ABSTRACT FROM AUTHOR]

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In recent decades, the risk of developing opportunistic infections has increased in parallel with the ever-increasing number of people suffering from chronic immunosuppressive diseases or undergoing prosthetic surgery. Staphylococcus warneri is a Gram-positive and coagulase-negative bacterium. Usually found as a component of the healthy human and animal microbiota of the skin and mucosae, it can take on the role of an opportunistic pathogen capable of causing a variety of infections, ranging from mild to life-threatening, not only in immunocompromised patients but even, although rarely, in healthy people. Here, in addition to a concise discussion of the identification and distinguishing features of S. warneri compared to other staphylococcal species, a systematic overview of the findings from case reports and clinical studies is provided. The paper highlights the virulence and antibiotic resistance profiles of S. warneri, the different clinical contexts in which it has proven to be a serious pathogen, emphasizing its ability to colonize artificial prosthetic materials and its tropism for musculoskeletal and cardiovascular tissues. Some original data on orthopedic implant infections by S. warneri complement the discussion. Finally, from a different perspective, the paper addresses the possibilities of industrial exploitation of this bacterium. [ABSTRACT FROM AUTHOR]

Investigating the quality of bee products obtained across different geographical regions and analyzing their antimicrobial activity is of significant interest to various scientific disciplines. This study focuses on comparing the antimicrobial activity of honey and propolis samples from different areas of Alba County, Romania. The quality parameters of five samples of two types of bee products (honey and propolis) were assessed. Then, the samples were tested to comparatively determine their antimicrobial properties against 12 species of bacteria (Escherichia coli, Salmonella typhimurium, Salmonella enteritidis, Salmonella anatum, Salmonella choleraesuis, Pseudomonas aeruginosa, Pseudomonas fluorescens, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Bacillus subtilis, and Listeria monocytogenes) and 7 fungal strains (Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum, Rhizopus stolonifer, Fusarium oxysporum, and Alternaria alternata). Of the bacterial strains, the most sensitive to the action of honey samples were the two strains of Staphylococcus followed by P. fluorescens. The two strains of Pseudomonas and L. monocytogenes were the most sensitive to the activity of propolis. Of the fungal strains, F. oxysporum was the most sensitive to the actions of both honey and propolis, followed by P. chrysogenum in the case of honey samples and the two Aspergillus strains in the case of propolis. These findings indicate that bee products are rich sources of bioactive compounds exhibiting strong antimicrobial properties and significant potential for the development of new phytopharmaceutical products. [ABSTRACT FROM AUTHOR]

Microbial contamination remains a global issue threatening human health. In this research, silver nanoparticles (AgNPs) were fabricated using Osmanthus fragrans flower extract as a reducing agent, and biochar derived from carbonizing waste barley distillers' grain shells was used as a support to fabricate silver-loaded carbon (C-AgNP, C-Ag). PVA-CS-C-Ag-St gel was acquired by cross-linking polyvinyl alcohol (PVA), chitosan (CS), and starch (St) with glutaraldehyde (GA). Results from SEM, FTIR, and XRD demonstrated that PVA, CS, St, and C-Ag were successfully incorporated into the gel. The PVA-CS-C-Ag-S gel showcased excellent swelling and water retention properties, which had substantial antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, with inhibition zones of 25.0 mm, 22.5 mm, and 18.0 mm, respectively. Finally, the antimicrobial analysis revealed that PVA-CS-C-Ag-St gel exhibited excellent antimicrobial properties against typical Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Overall, the PVA-CS-C-Ag-St gel holds great promise for food preservation and environmental pollution control. [ABSTRACT FROM AUTHOR]

The machining of implants and parts for dental prostheses to eliminate biofilm in the implantoplasty process causes a loss of mechanical properties and also characteristics of the surfaces, making tissue regeneration difficult. In the present work, treatments consisting of elements that can reduce infection, such as citric acid and magnesium, together with elements that can improve cell adhesion and proliferation, such as collagen, are proposed for implant–crown assembly. Titanium, zirconia, composite (PMMA + feldspar) and cobalt–chromium discs were immersed in four different solutions: 25% citric acid, 25% citric acid with the addition of collagen 0.25 g/L, 25% citric acid with the addition of 0.50 g/L and the latter with the addition of 1% Mg (NO3)2. After immersion was applied for 2 and 10 min, the roughness was determined by interferometric microscopy and the contact angle (CA) was evaluated. Human fibroblastic and osteoblastic line cells (HFFs and SaOS-2) were used to determine cell viability and proliferation capacity. Cell binding and cytotoxicity were determined by resazurin sodium salt assay (Alamar Blue) and cell morphology by confocal assay (immunofluorescence F-actin (phalloidin)) after 3 days of incubation. For the evaluation of bacterial activity, the bacterial strains Sptreptococcus gordonii (Gram+) and Pseudomonas aeruginosa (Gram−) were used. The antibacterial properties of the proposed treatments were determined by means of the resazurin sodium salt (Alamar Blue) assay after 1 day of incubation. The treatments considerably decreased the contact angle of the treated samples with respect to the control samples. The treatments endowed the surfaces of the samples with a hydrophilic/super-hydrophilic character. The combination of elements proposed for this study provided cell viability greater than 70%; considering the absence of cytotoxicity, it therefore promotes the adhesion and proliferation of fibroblasts and osteoblasts. In addition, it also endows the surface with antibacterial characteristics against from Gram+ and Gram− bacteria without damaging the cells. These results show that this mouthwash can be useful in oral applications to produce a new passivation layer that favors the hydrophilicity of the surface and promotes cellular activity for the formation of fibroblasts and osteoblasts, as well as showing bactericidal activity. [ABSTRACT FROM AUTHOR]