Enterococcus Faecalis Research Articles

Screening and identification of phytochemicals from Acorus calamus L. to overcome NDM-1 mediated resistance in Klebsiella pneumoniae using in silico approach

Klebsiella pneumoniae is a potent human pathogen and a prevalent ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). Considerably, K. pneumoniae becomes a major clinical problem due to numerous AMR genes [extended-spectrum β-lactamase, plasmid-mediated AmpC, carbapenemases, tigecycline resistance, and New Delhi Metallo-β-lactamase-1 (NDM-1)] and can hydrolyse the majority of β-lactam antibiotics. Hence, targeting NDM-1 could be an effective approach to eradicate K. pneumoniae pathogenesis. A plethora of reports suggests that the plant compounds possess an anti-microbial activity and their utilization could be a promising strategy to develop novel antibiotics. Our study utilized the hydromethanolic leaves extract of Acorus calamus L. (AC) to target NDM-1 containing K. pneumonia using an in silico approach. At first, we determined the phytochemical composition of AC using GC-HRMS. Further, the phytoconstituents were screened against the NDM-1 (PDB ID: 3ZR9) of K. pneumoniae through molecular docking studies. Our results revealed the compounds from AC such as [(2R,4S,6R,7S,8R,9S,13S)-16-hydroxy-5’,7,9,13-tetramethylspiro[5-oxapentacyclo[10.8.0.02,9.04,8.013,18]icos-1(12)-ene-6,2’-oxane]-11-one (-9.5 kcal/mol), 4,4,5,8-tetramethyl-2,3-dihydrochromen-2-ol (-6.6 kcal/mol), 5-chloro-2-(2,4-dichloro phenoxy)phenol (-6.0 kcal/mol), [(3S,3aS,6R,6aS)-3-nitrooxy-2,3,3a,5,6,6a-hexahydrofuro[3,2-b]furan-6-yl] nitrate (-5.7 kcal/mol), 4-(3-hydroxyprop-1-enyl)-2-methoxyphenol (-5.6 kcal/mol), and (E)-3-(2,4-dimethoxyphenyl)prop-2-enoic acid (-5.6 kcal/mol)] possess substantial docking scores against NDM-1. Therefore, our study concludes that phytochemicals of AC may inhibit NDM-1-mediated resistance in K. pneumoniae and could be an alternative therapeutic strategy for targeting NDM-1-containing K. pneumoniae.

The Clinical Application Value of a Novel Chip in the Detection of Pathogens in Adult Pneumonia: A Multi-Centre Prospective Study in China.

The detection of pathogenic microorganisms plays a significant role in the diagnosis and management of pneumonia that are responsible for a substantial number of deaths worldwide. However, conventional microbiological tests (CMT) have low accuracy and are time-consuming. In this study, we aim to evaluate the clinical value of Chips for Complicated Infection Detection (CCID) in detecting pneumonia pathogens. This study was conducted at nine hospitals in China from January 2021 to September 2022. Respiratory samples from adult pneumonia patients were collected from each patient. CMT and CCID were performed in parallel to identify the pathogens. A total of 245 patients were included, with 73% being elderly. CCID identified pathogenic microbes in 78.0% of patients and conventional microbiological tests (CMT) in 57.1% of the patients (p<0.001). The overall positive and negative percent agreements between CCID and CMT for pathogen detection were 90.07% and 38.46%, respectively. 38.8% of patients were diagnosed with mixed infections with at least two pathogens by CCID. Bacterial infections identified by CCID accounted for 60.0% of 245 patients, with the top 3 being Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterococcus faecium, respectively. K. pneumoniae was the most common pathogen in elderly patients, with a significantly higher prevalence compared to non-elderly patients (p = 0.0011). Among the 197 patients who had used antibiotics before sample collection, the positive rate of CCID was significantly higher than that of CMT (p < 0.001). This study indicates that compared to CMT, this novel chip has significant advantages in detecting pathogens in pneumonia patients, especially in the elderly.

Colorimetric polymerase chain reaction mediated by pH indicator: rapid detection of drug-resistant nosocomial bacteria

Polymerase chain reaction (PCR) is the gold standard for molecular diagnoses due to its high sensitivity and accuracy. However, conventional PCR exhibits limitations including extended analysis time and complicated sample treatment. To shorten the analysis time of standard three-step PCR, we employed a two-step PCR allowing for fast amplification of nucleic acid in a chip format. Moreover, to realize a fully-integrated and on-site visual discrimination of opportunistic and multidrug-resistant pathogens, namely, Enterococcus faecium and Acinetobacter baumannii. DNA was extracted using FTA card, and pH-dependent color changes of the PCR amplicons were monitored by using phenolphthalein as a pH indicator. The overall reaction took less than 35 min and exhibited high selectivity and sensitivity confirmed by the limit of detection of approximately 103 CFU/mL for E. faecium. In addition, carbapenem-resistant A. baumannii was successfully detected demonstrating the clinical applicability of the introduced technique using a thermoplastic chip. E. faecium both in bacterial cell culture solution and a contaminated surface were also successfully detected proving the feasibility of the chip-based detection system and paving the way for a facile discrimination of opportunistic pathogens prevalent in hospitals and our environment.

Synergistic Action of Rutin-Coated Zinc Oxide Nanoparticles: Targeting Biofilm Formation Receptors of Dental Pathogens and Modulating Apoptosis Genes for Enhanced Oral Anticancer Activity.

Oral diseases are often associated with bacterial and fungal pathogens such as Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, and Candida albicans. This research explored a novel approach to addressing these pathogens by synthesizing zinc oxide nanoparticles (ZnO NPs) coated with rutin (RT), a plant-derived compound. The synthesized ZnO-RT NPs were comprehensively characterized using UV-Vis spectrophotometer, SEM, and EDAX techniques to confirm their structural composition. The antioxidant potential was assessed through free radical scavenging assays. Additionally, the antimicrobial activity of ZnO-RT NPs was evaluated using a zone of inhibition assay against oral pathogens. Molecular docking studies with the Autodock tool were performed to elucidate the interactions between RT and the receptors of oral pathogens. The findings demonstrated that ZnO-RT NPs exhibited robust free radical scavenging activity. Furthermore, they showed significant antimicrobial activity with a minimal inhibitory concentration of 40 μg/mL against oral pathogens. ZnO-RT NPs also displayed dose-dependent anticancer effects on human oral cancer cells at concentrations of 10, 20, 40, and 80 μg/mL. Mechanistic insights into the anticancer activity on KB cells revealed the upregulation of apoptotic genes. This study underscores the promising potential of ZnO-RT NPs for dental applications due to their strong antioxidant, anticancer, and antimicrobial properties. These nanoparticles offer a hopeful prospect for addressing oral pathogen challenges and enhancing overall oral health.

Physicochemical, optical and magnetic properties of ZrO2/Fe2O3 nanocomposite and its application in photocatalysis and antibacterial treatment

In this work ZrO2/Fe2O3 nanocomposite was synthesised through hydrothermal method using an innovative approach. X-ray diffraction (XRD) analysis revealed the formation of tetragonal ZrO2 and α-Fe2O3 in the nanocomposite. The FTIR spectra of the prepared samples exhibited characteristic peaks corresponding to ZrO2 and Fe2O3 and UV–Visible spectroscopy reveals that the nanocomposite exhibits a significantly lesser bandgap than the pure nanoparticles as determined by the Kubelka Munk function used for bandgap computation. Photoluminescence analysis substantiates the reduction in the recombination rate in the ZrO2/Fe2O3 nanocomposite as compared to the pure ZrO2 nanoparticles. Reduction in the bandgap as well as the recombination rate makes the nanocomposite favourable in the photocatalytic treatment of organic pollutants. Raman analysis was carried out to study the vibrational characteristics of the samples. Further, the prepared nanocomposite was examined for its applicability in photocatalysis, by analysing its degradation ability on Eosin yellow and Eosin Blue dyes under white light LED irradiation. The composite exhibited significant degradation ability than the pure nanoparticles, which makes it an ideal candidate for the treatment of organic pollutants. The nanocomposite exhibited ferromagnetic behaviour as confirmed through Vibrating sample Magnetometry, so it can be easily retrieved after the treatment. The prepared ZrO2/Fe2O3 nanocomposite was tested for its antibacterial efficacy against two Gram positive bacteria (Enterococcus faecalis, Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa). From the antibacterial studies it was validated that the nanocomposite exhibited significant antibacterial efficiencies against the bacteria. Hence the prepared nanocomposite has been proved to be a potential candidate for the treatment of organic pollutants as well as for antibacterial treatment.

Enhanced photocatalytic and antibacterial performance of CeO2-loaded carboxymethyl chitosan nanocomposites.

Carboxymethyl chitosan (CMCs) was loaded with two different concentrations of cerium dioxide (CeO2), specifically 0.3 g and 0.6 g, and compared with pure CMCs. XRD and FTIR analyses were used to evaluate the structural characteristics. The nanocomposites were examined for their photocatalytic degradation of Methylene Blue (MB) dye and antibacterial capabilities. Various parameters, including catalyst concentration, dye concentration, and pH levels, were assessed to determine the photocatalytic degradation efficiency of MB dye. The results demonstrated that the 0.6CeO2/CMCs nanocomposite outperformed the 0.3CeO2/CMCs and pure CMCs in terms of photocatalytic performance, achieving complete degradation of MB dye within 210 and 240 min after treatment with 0.3CeO2/CMCs and 0.6CeO2/CMCs nanocomposites. The agar well diffusion test was employed to assess the antibacterial activity of the nanocomposites against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. The 0.6CeO2/CMCs nanocomposite exhibited the highest antibacterial effectiveness, with zones of inhibition measuring 29 ± 0.63 mm for E. coli, 28 ± 0.18 mm for P. aeruginosa, 25.5 ± 0.25 mm for S. aureus, and 23.6 ± 0.51 mm for E. faecalis. Additionally, the durability and reusability of the nanocomposites were confirmed after undergoing 5 cycles of MB dye degradation, with only a slight decrease in efficiency. The findings of this study highlight the potential of CeO₂/CMCs nanocomposites as powerful antibacterial and photocatalysts with important implications for environmental and biological applications.

Facile fabrication and characterization of carboxymethyl cellulose loaded with TiO2NPs hydrogel as a promising disinfectant for eliminating the dissemination of waterborne pathogens through wastewater decontamination

The purpose of this work was to develop and characterize an intriguing hydrogel called TiO₂NPs@CMC hydrogel, which is composed of carboxymethyl cellulose (CMC) and loaded with titanium oxide nanoparticles (TiO₂NPs) for effective waterborne pathogen disinfection in wastewater. The TiO₂NPs were synthesized through hydrolysis and peptization, incorporated into a CMC matrix, and subsequently cross-linked with calcium chloride (CaCl₂). Characterization through TEM, FTIR, and SEM validated the development of a porous structure, efficient incorporation of TiO₂NP, and successful crosslinking. In this study, TiO2NPs were prepared and affirmed the significant particle distribution with a small size using TEM. The TiO₂NPs@CMC hydrogel exhibited significant antimicrobial and antibiofilm properties against various pathogens, such as Salmonella typhi, E. coli O157, Shigella dysenteriae, Enterococcus faecalis, Bacillus cereus, and Candida albicans, with highest inhibition zone diameters of up to 29 mm for S. typhi. The inhibitory effect demonstrated that the hydrogel significantly decreased bacterial populations at 100 μg/mL concentrations. The hydrogel demonstrated a 2.7-log reduction in microbial counts in sewage water within 120 min, achieving complete inactivation of pathogens at a concentration of 2xMIC within 180 min. The biofilm inhibition rate reached 87.6 % against B. cereus. Toxicity assessments demonstrated significant biocompatibility, with no negative effects noted in environmental applications. The findings indicate that TiO₂NPs@CMC hydrogel is a viable option for sustainable wastewater treatment, providing an efficient, safe, and environmentally friendly method for the removal of waterborne pathogens and the prevention of biofilm formation.

Multifunctional Applications of Gd‐Doped ZnO Nanoparticles Prepared Easily by the Coprecipitation Method

AbstractThe present work involves the preparation of pure ZnO and gadolinium‐doped ZnO nanoparticles with the general formula GdxZn1−xO (X = 0–0.05) by wet chemical coprecipitation technique. XRD outcomes confirmed that these nanoparticles exhibited a hexagonal wurtzite structure of zinc oxide lacking any secondary phase. The calculated average crystallite size declined from 33 to 28 nm. Through SEM analysis, the shape and morphology of the sample were determined, which showed nanoflakes‐like structures, and EDS analysis confirmed the elemental composition of Gd‐doped ZnO nanoparticles. UV–vis DRS spectral studies indicate good optical capabilities with a decline in the bandgap from 3.4 to 2.6 eV with an incline in doping concentration. Photoluminescence studies exhibited a green emission peak at 378 nm. Additionally, photodegradation of these nanoparticles was assessed through degradation of MB dye, which showed 94% of dye degradation. Synthesized nanoparticles show good electrochemical performance in CV studies. Pure ZnO and Gd‐ZnO were examined against Gram‐positive Enterococcus faecalis and Gram‐negative Escherichia coli bacteria, and it was initiated that the zone of inhibition of antibacterial activity improved with gadolinium doping compared to the pure ZnO nanoparticles.

Investigation of Nosocomial Urinary Tract Infections Post Transplantation, Main Pathogens, and Sensitivity Tests

Background: Regarding end-stage organ disease, transplantation is recommended as the best therapeutic management. After organ transplantation, the incidence of nosocomial urinary tract infections (NUTIs) due to multidrug-resistant Gram-negative bacilli increases. Aim: The study aimed to investigate NUTIs post-transplantation, the main pathogens involved, and sensitivity tests conducted in a tertiary hospital in Isfahan, Iran. Methods: A retrospective survey on patients admitted to a tertiary hospital in Isfahan (Alzahra), Iran, was performed between 27 March, 2017, and 9 February, 2022. The information recorded included the date of infection, date of hospitalization, gender, age, type of pathogens, and resistance or sensitivity to antibiotics. Results: 73 kidney transplant recipients (61% females) with a mean age of 43. 2 ± 15.1 years were included. Within this population involving both genders, the main pathogens involved in NUTIs were as follows: Escherichia coli (30%), Klebsiella pneumonia (19%), Candida albicans and non-albicans (14%), Enterococcus faecalis (12%), Enterobacteriaceae (8%), Pseudomonas aeruginosa (6%), Staphylococcus spp. (6%), Acinetobacter baumannii (4%), and Streptococcus spp. (4%). Antibiotic susceptibility testing showed the most sensitivity of isolates against amikacin (n=29; 66%), meropenem (n= 28; 64%), piperacillin/tazobactam (n=26; 54%), cefepime (n= 25; 40%), ceftazidime (n= 27; 30%), ciprofloxacin (n= 40; 18%), and co-trimoxazole (n= 29; 10%). Conclusion: Escherichia coli, Klebsiella pneumonia, and Candida spp. were the major causes of NUTIs within the studied organ-transplanted recipients. Amikacin, meropenem, and piperacillin/ tazobactam have shown more than 50% sensitivity against isolates. Further evidence-based pharmacotherapy investigations associated with the different spectrum antibiotics and overall antimicrobial success rate is recommended to be advantageous.

Nanostructured silver vanadate gel: Evaluation of physicochemical, mechanical, and antibiofilm properties against a five-species oral model

The aim of this study was to develop a gel with nanostructured silver vanadate decorated with silver nanoparticles (β-AgVO3) and to evaluate its physicochemical, mechanical, and antibiofilm properties against a five-species oral model composed of Candida albicans, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa. The formulations were prepared with 0 % w/v (G0), 0.02 % w/v (G1), 0.05 % w/v (G2), and 0.12 % w/v (G3) β-AgVO3. The physicochemical properties of pH (n = 5), viscosity (n = 5), spreadability (n = 10) and syringability (n = 10) were evaluated, as well as the mechanical properties of hardness, cohesiveness, compressibility, elasticity, and adhesiveness using the texture profile assay (TPA) (n = 5) and ex vivo mucoadhesion (n = 5). The antibiofilm effect was assessed by counting colony-forming units (CFU/mL) (n = 8), metabolic activity (XTT) (n = 8), and scanning electron microscopy (SEM) (n = 1), using 0.12 % chlorhexidine gel (CG) as a positive control and G0 as a negative control. All groups demonstrated a neutral pH. G2 and G3 exhibited reduced viscosity and syringeability, along with increased spreadability. The incorporation of β-AgVO3 did not impact the gel's elasticity or cohesiveness but led to a decrease in hardness, compressibility, and adhesiveness. Ex vivo mucoadhesion was not altered by the addition of the nanomaterial. G3 showed a higher microbial reduction compared to GC and G0. It was concluded that the formulations with β-AgVO3 showed compatible physicochemical and mechanical properties for application and maintenance in the oral cavity. G3 showed superior antimicrobial effect against all microorganisms compared to GC and G0.

Unveiling the interaction, cytotoxicity and antibacterial potential of pyridine derivatives: an experimental and theoretical approach with bovine serum albumin.

The binding interactions between bovine serum albumin (BSA) and three pyridine derivatives, i.e., 2-(5-bromopyridin-3-yl) acetic acid (L1), 3-bromo-5-nitropyridine (L2) and 2-chloro-4-nitropyridine (L3), have been carried out using UV-Vis and fluorescence spectroscopic methods. Fluorescence intensity quenching is observed by adding L2 and L3 to the BSA solution. The quenched fluorescence emission is due to the static nature. An isothermal titration calorimetry (ITC) experiment shows the binding ability of L1 with BSA. The binding constants are found to be 7.23 ± 0.32 × 105 M-1 for L1. The thermodynamic parameters were calculated from ITC measurements (i.e., ∆H = -2.78 ± 0.08 kcal/mol, ∆G = -5.65 ± 0.25 kcal/mol, and -T∆S = -2.87 ± 0.11 kcal/mol), which indicated that the protein-ligand complex formation between L1 and BSA is mainly due to the hydrogen bonds and van der Waals interactions. Cyclic voltammetry (CV) and structure activity and relationship (SAR) studies have been carried out to establish the relationship between ligands and proteins. Additionally, we conducted an antibacterial assay with gram-positive Staphylococcus aureus, Enterococcus faecalis, and negative bacterial strains Acinetobacter baumannii and Escherichia coli against L1, L2, and L3, aiming to address the challenges posed by the co-existence of multidrug-resistant bacteria. Finally, drosophila is used to test the cytotoxicity of ligands L1, L2, and L3's in vitro.

Analysis of a persistent outbreak with vancomycin resistant Enterococcus faecium (VREfm) revealed the need for an adapted diagnostic algorithm

Our setting was challenged with an outbreak of different vancomycin resistant Enterococcus faecium (VREfm) including vanA and/or vanB containing isolates. Remarkably, it was observed that screening by use of a vanA and vanB real-time PCR on overnight enriched specimens from time to time tested positive for VanB with very low Ct-values, whereas VREfm-specific enrichment cultures remained negative. Here, we describe the analysis of the diagnostic results leading to adaptation of the diagnostic algorithm. Per specimen of each patient, results of the vanA and vanB screening PCR and of the VREfm-specific culture (Brilliance VRE) were collected and combined with genotyping data of the identified VREfm isolates. During the outbreak, a second VREfm-specific culture medium (CHROMagar VRE) was introduced, and results were compared to the results obtained with Brilliance VRE agar. Thirty-five patients were identified as VREfm-carrier, in which four different strains were identified comprising vanA (STnew-CT7088) and/or vanB (ST80-CT1065, ST117-CT7117 and ST117-CT7118). Complementing results of PCR, culture and genotyping revealed that culture with Brilliance VRE agar was inadequate for detection of the vanB ST117 isolates identified, irrespective of vancomycin MIC values. In contrast, CHROMagar VRE was able to correctly detect these vanB ST117 isolates and other tested isolates. Our data showed that the vanB ST117 containing isolates were inadequately detected by the VREfm-specific culture media, possibly contributing to unnoticed spread of VREfm. For this reason, CHROMagar VRE was evaluated during the outbreak and subsequently implemented in routine diagnostics, replacing Brilliance VRE agar.

Efficacy of the feed additives consisting of Enterococcus faecium ATCC 53519 and E. faecium ATCC 55593 as silage additives for all animal species (FEFANA asbl).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the efficacy of two technological additives (functional group: silage additives) consisting of Enterococcus faecium strains ATCC 53519 and ATCC 55593, respectively. The additives are intended for use with all types of fresh materials and for all animal species at a proposed minimum concentration of 1 × 107 colony-forming units of E. faecium ATCC 53519/kg fresh material or 5 × 106 CFU of E. faecium ATCC 55593/kg fresh material. In a previous opinion, the FEEDAP Panel could not conclude on their efficacy since the dry matter content of the ensiled materials at the end of the experiments was not corrected for volatiles, which led to unreliable estimation of the dry matter loss, and the lack of positive effects on any of the other parameters. The supplementary information submitted by the applicant included updated data on the dry matter loss corrected for volatiles. The results showed that, at the end of the ensiling process, the dry matter loss during the ensiling was significantly lower in the ensiled materials treated with E. faecium ATCC 53519 or ATCC 55593 compared to controls. The FEEDAP Panel concludes that the addition of E. faecium ATCC 53519 or ATCC 55593 in all types of fresh plant materials shows potential to improve the nutrient preservation of silage at the proposed conditions of use.

Impact of COVID-19 on the Prevalence and Drug Resistance of Bacteria Isolated From Bacterial Meningitis Cerebrospinal Fluid in Shandong Province: A Multicenter Retrospective Study.

Our objective was to evaluate the ramifications of the 2019 coronavirus disease (COVID-19) pandemic on the microbial profile and antimicrobial resistance patterns of bacteria isolated from cerebrospinal fluid (CSF) specimens of patients with bacterial meningitis. We conducted a retrospective analysis of laboratory results and clinical records about positive CSF cultures reported by the SPARSS network from 2017 to 2023. The study covered three distinct periods: January 2017 to December 2019 (before the COVID-19 pandemic), January 2020 to December 2022 (during the COVID-19 pandemic), and January 2023 to December 2023 (after the COVID-19 pandemic), with a total of 5793 CSF isolates collected. Notably, the proportion of male patients (61.3%) was higher than that of females. After COVID-19, we observed a notable shift in the seasonal peak of CSF pathogens, with a delay of approximately 3 months. Remarkable alterations were evident in both pediatric and adult CSF isolate profiles. In children, the predominant pathogens included coagulase-negative Staphylococcus (CoNS), Streptococcus pneumonia, and Escherichia coli. Notably. After COVID-19, there was a significant decrease in the proportion of CoNS (p = 0.0039) and a notable increase in E. coli (p = 0.0067). In adults, the top three pathogens were CoNS, Acinetobacter baumannii, and Klebsiella pneumoniae. After the pandemic, we observed a significant reduction in the prevalence of A. baumannii (p = 0.0059), while the proportions of K. pneumoniae, Pseudomonas aeruginosa, Enterobacter cloacae, and Enterococcus faecalis increased significantly (p < 0.05). Additionally, among multidrug-resistant bacteria, the detection rate of carbapenem-resistant E. coli escalated (p = 0.0375). Antimicrobial susceptibility analysis indicated a declining trend in resistance rates for CoNS and A. baumannii to certain antibiotics following the pandemic. Conversely, resistance to imipenem in A. baumannii increased. In conclusion, the COVID-19 pandemic has significantly influenced the composition, antimicrobial resistance patterns, and epidemiological dynamics of CSF-isolated bacteria in Shandong province. To effectively address these changes, ongoing and dynamic surveillance of pathogen trends and antimicrobial resistance rate is essential.

A Novel pH-Responsive Nano-Sized Lanthanum-Doped Polyvinyl Alcohol-Carbon Quantum Dot Composite for Root Canal Irrigation.

The primary goals of endodontic therapy are to eliminate microbes and prevent reinfection. Persistent root canal infections and failure of root canal therapy are primarily attributed to the presence of bacteria, particularly E. faecalis. Chemical irrigants play a crucial role in complementing mechanical instrumentation in ensuring adequate disinfection. However, current techniques and available irrigants are limited in their ability to achieve optimal sterilization of the root canal system. In this study, we developed a novel material called La@PCDs by combining CQD-PVA and lanthanum for root canal irrigation. A one-pot hydrothermal method was used to prepare composites of lanthanum and CQD-PVA (La@PCDs). Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and the particle size were employed to characterize La@PCDs. ROS generation was evaluated by measuring the fluorescence intensity emitted at 525 nm from 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA). In vitro experiments were conducted to assess the effectiveness of the nanoparticles in combating Enterococcus faecalis and eradicating in situ biofilm eradication in root canal. Furthermore, cytotoxicity assessments were carried out to demonstrate the safety of La@PCDs. SEM and FTIR results showed that La@PCDs were successfully prepared and exhibiting a homogeneous size distribution and irregular morphology. ROS assessment demonstrated that La@PCDs have a synergistic effect, promoting the production of a large number of ROS. This effect only occurred under acidic PH conditions. The inherent acidity in the biofilm microenvironment can act as internal stimulus. In vitro experiments revealed superior antibacterial efficiency under acidic conditions without causing significant cytotoxicity compared to the commonly used NaClO irrigant. The biosafety of La@PCDs was confirmed. Compared to existing materials, these nanoparticles exhibit favorable antibacterial and anti-biofilm properties, along with improved biocompatibility. These findings emphasize the potential of the integrated La@PCDs as a promising option for enhancing root canal irrigation and disinfection.

The microbiome biomarkers of pregnant women's vaginal area predict preterm prelabor rupture in Western China.

Intraamniotic infection is crucial in preterm prelabor rupture of membranes(PPROM), a clinical condition resulting from the invasion of vaginal opportunistic microbes into the amniotic cavity. Although previous studies have suggested potential associations between infection and PPROM, the role of vaginalopportunistic bacteria in PPROM has received limited attention. This study aimed to confirm the vaginal bacterial etiology of PPROM. We investigated vaginal microbiotas using automatic analysis of vaginal discharge, microbiological tests, and 16s rRNA genehigh-throughput sequencing. The research findings revealed that the proportion of parabasal epitheliocytes, leukocytes, toxic leukocytes, and bacteria with diameters smaller than 1.5 um was significantly higher in the PPROM group than that in the normal full-term labor (TL) group. The top three vaginal opportunistic bacterial isolates in all participants were 9.47% Escherichia coli, 5.99% Streptococcus agalactiae, and 3.57% Enterococcus faecalis. The bacterial resistance differed, but all the isolates were sensitive to nitrofurantoin. Compared with the vaginal microbiota dysbiosis (VMD) TL (C) group, the VMD PPROM (P) group demonstrated more operational taxonomic units, a high richness of bacterial taxa, and a different beta-diversity index. Indicator species analysis revealed that Lactobacillus jensenii, Lactobacillus crispatus, and Veillonellaceae bacterium DNF00626 were strongly associated with the C group. Unlike the C group, the indicator bacteria in the P group were Enterococcus faecalis, Escherichia coli, and Streptococcus agalactiae. These findings provide solidevidence that an abnormal vaginal microbiome is a very crucial risk factorclosely related to PPROM. There were no unique bacteria in the vaginalmicrobiota of the PPROM group; however, the relative abundance of bacteria inthe abnormal vaginal flora of PPROM pregnancies differed. Antibiotics should bereasonably selected based on drug sensitivity testing. The findings presented in this paper enhance our understanding of Streptococcus agalactiae, Enterococcus faecalis, and Escherichia coli vaginal bacterial etiology of PPROM in Western China.

Antioxidative and Antimicrobial Activity of 2-Amino Substituted Halochalcone N-Glycoside Derivative Compounds

Introduction: The aim of this study was to specify the antioxidant and antimicrobial activity synthesized 2-amino substituted halochalcone N-glycoside derivative compounds. Methods: The antioxidant capacity of synthesized compounds (1-4) was determined by cupric ion reducing antioxidant capacity (CUPRAC), and ferric reducing antioxidant power (FRAP). Antimicrobial activity was determined on 9 microorganism by agar well diffusion method.Results: According to the study results, compound 3 showed the highest antioxidant activity. The compound 3 showed antimicrobial activity against Yersinia pseudotuberculosis, Pseudomonas aeruginosa, Candida albicans while compound 4 showed antimicrobial activity against Escherichia coli, Yersinia pseudotuberculosis, Pseudomonas aeruginosa, Enterococcus faecalis, Bacillus cereus, Staphylococcus aureus.Conclusion: 2-amino substituted halochalcone N-glycoside derivative compounds could be evaluated in the pharmaceutical and cosmetic fields due to their antioxidant and antimicrobial potential.

Monoterpene Hydroxy Lactones Isolated from Thalassiosira sp. Microalga and Their Antibacterial and Antioxidant Activities.

Two monoterpenoid lactones, loliolide (1) and epi-loliolide (2), were isolated from the crude dichloromethane extract of a microalga, Thalassiosira sp.). The structures of loliolide (1) and epi-loliolide (2) were elucidated by 1D and 2D NMR analysis, as well as a comparison of their 1H or/and 13C NMR data with those reported in the literature. In the case of loliolide (1), the absolute configurations of its stereogenic carbons were confirmed by X-ray analysis, whereas those of epi-loliolide (2) were determined by NOESY correlations. Loliolide (1) and epi-loliolide (2) were tested for their growth inhibitory activity against two Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212) and two Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) bacteria, as well as one clinical isolate (E. coli SA/2, an extended-spectrum β-lactamase producer-ESBL) and two environmental isolates, S. aureus 74/24, a methicillin-resistant (MRSA), and E. faecalis B3/101, a vancomycin-resistant (VRE) isolates. The results showed that none of the tested compounds exhibited antibacterial activity at the highest concentrations tested (325 μM), and both revealed low antioxidant activity, with ORAC values of 2.786 ± 0.070 and 2.520 ± 0.319 µmol TE/100 mg for loliolide (1) and epi-loliolide (2), respectively.

Metabolic interplay between Proteus mirabilis and Enterococcus faecalis facilitates polymicrobial biofilm formation and invasive disease.

Biofilms play an important role in the development and pathogenesis of catheter-associated urinary tract infection (CAUTI). Proteus mirabilis and Enterococcus faecalis are common CAUTI pathogens that persistently co-colonize the catheterized urinary tract and form biofilms with increased biomass and antibiotic resistance. In this study, we uncover the metabolic interplay that drives biofilm enhancement and examine the contribution to CAUTI severity. Through compositional and proteomic biofilm analyses, we determined that the increase in biofilm biomass stems from an increase in the protein fraction of the polymicrobial biofilm. We further observed an enrichment in proteins associated with ornithine and arginine metabolism in polymicrobial biofilms compared with single-species biofilms. We show that arginine/ornithine antiport by E. faecalis promotes arginine biosynthesis and metabolism in P. mirabilis, ultimately driving the increase in polymicrobial biofilm protein content without affecting viability of either species. We further show that disrupting E. faecalis ornithine antiport alters the metabolic profile of polymicrobial biofilms and prevents enhancement, and this defect was complemented by supplementation with exogenous ornithine. In a murine model of CAUTI, ornithine antiport did not contribute to E. faecalis colonization but was required for the increased incidence of urinary stone formation and bacteremia that occurs during polymicrobial CAUTI with P. mirabilis. Thus, disrupting metabolic interplay between common co-colonizing species may represent a viable strategy for reducing risk of bacteremia.IMPORTANCEChronic infections often involve the formation of antibiotic-resistant biofilm communities that include multiple different microbes, which pose a challenge for effective treatment. In the catheterized urinary tract, potential pathogens persistently co-colonize for long periods of time and the interactions between them can lead to more severe disease outcomes. In this study, we identified the metabolite L-ornithine as a key mediator of disease-enhancing interactions between two common and challenging pathogens, Enterococcus faecalis and Proteus mirabilis. Disrupting ornithine-mediated interactions may therefore represent a strategy to prevent polymicrobial biofilm formation and decrease risk of severe disease.

Development of a PCR assay for rapid and accurate detection of an emerging vanB Enterococcus faecium clone in the Capital Region of Denmark.

To develop and validate a real-time PCR assay detecting the sequence bridging Tn1549 and the Enterococcus faecium chromosome in the emerging vanB vancomycin-resistant E. faecium (VREfm) clone (ST80/CT2406). The Tn1549 insertion site was determined on routinely sequenced VREfm isolates. The outer boundaries of Tn1549 and adjoining host bacterial sequences were determined using a BLAST search in the silent information regulator gene sir2. Next, the primers and probe were developed, targeting the sequence bridging Tn1549 and the E. faecium chromosome. Finally, the PCR assay was validated on well-characterized strains and prospectively performed on rectal screening samples submitted to our laboratory. The PCR assay proved to be accurate and provide rapid diagnosis of the emerging vanB VREfm in rectal screening samples.