Inhibition Diameter Research Articles

Chemical composition and antifungal activity of Teucrium Leucocladum Boiss. essential oils growing in Egypt using two different techniques

BackgroundTeucrium Leucocladum Boiss. (TL) (family Lamiaceae), indigenous to Sinai, Egypt, and Mediterranean region, is considered a rich source of essential oils (EOs). This study aimed to extract the aerial parts essential oils utilizing hydro-distillation (HD) and microwave-assisted extraction (MAE), and analyze the volatile constituents by Gas Chromatography–Mass Spectrometry (GC/MS). The antifungal and cytotoxic potentials against Candida albicans (C. albicans) and non-small cell lung adenocarcinoma A549, triple-negative breast cancer MDA-MB-231 cell lines, respectively, were likewise estimated. Subsequently, the three main compounds were docked into the crystal structure of Candida albicansN-myristoyltransferase (NMT) with myristoyl-COA and peptidic inhibitor (PDB 1IYK), and predictions of human absorption, distribution, metabolism, and excretion (ADME) were performed to assess the drug-likeness of the compounds.ResultsThe chemical profile consisted of monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons, and oxygenated sesquiterpenes. The MAE oil sample (TLM) yield was found to be double that of the HD oil sample (TLH). TLM afforded an inhibitory diameter (13 mm) comparable to the ketoconazole (20 mm), TLM 100 mg/mL showed the strongest antifungal potential against C. albicans. The cytotoxic assay revealed moderate activity against A549 and MDA-MB-231. In silico studies using molecular docking were processed on the major components in which nerolidol had the best-fitting energy to inhibit C. albicans (− 7.21 kcal/mol), while ADME results established a promising first step for the potential drug bioavailability.ConclusionIn this research, essential oil acquired from the aerial parts proved to contain monoterpenes and sesquiterpenes, which are classes of compounds known for their versatile usage in medicine. In vivo studies on Teucrium Leucocladum Boiss. active metabolites against clinical strains of fungi need to be further studied, as do the effects of combining the active compounds with antifungal agents to combat antimicrobial resistance.

Metabolomics Approach to Explore Bioactive Natural Products Derived From Plant-Root-Associated Streptomyces.

Streptomyces, a prominent genus within the Actinomycetota phylum, is responsible for over 60% of clinically relevant antibiotics. Streptomyces strains inhabiting plant roots possess the potential to synthesize bioactive natural products, conferring defense and resilience to plants against pathogenic microorganisms. However, this potential remains largely unexplored. This study aims to screen for bioactive metabolites produced by Streptomyces strains in the plant rhizosphere.Six Streptomyces isolates were cultivated using three modified media to induce the production of diverse metabolites, employing the One Strain Many Compounds (OSMAC) approach. The metabolites present in extracts from fermentation broths were examined through a non-targeted Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) approach coupled with Global Natural Products Social Molecular Networking (GNPS MN). The antimicrobial activity of the extracts was assessed using the disc diffusion method.The strains demonstrated a wide-ranging antimicrobial efficacy against all examined organisms. The GNPS molecular network analyses reveal that metabolite profiles in extracts can exhibit variations based on the medium and solvent system employed. Notably, the ethyl acetate and dichloromethane extracts from Streptomyces sp. CAH29, cultivated in Glucose-Yeast Extract Medium (GYM), exhibited inhibition diameters of up to 30mm against both Staphylococcus aureus and Candida albicans. Within the metabolomes of these strains, the antibiotics spiramycin and actinomycin were detected. Additionally, lyngbatoxin, a tumor promoter, and potential new analogs were identified. Significantly, a considerable portion of the produced metabolites did not align with any known compounds, indicating the existence of unidentified metabolites generated by these strains. This suggests the possibility of introducing novel chemical entities.Our study illustrated that Streptomyces strains associated with plant roots could be considered a valuable source of bioactive secondary metabolites. Furthermore, the metabolomics approach utilized in this study serves as a rapid and valuable tool for the screening of microorganisms capable of producing bioactive metabolites.

Comparative study of volatile oil constituents, anti-microbial properties, and antibiofilm activities in Eucalyptus camaldulensis and Eucalyptus globulus: insights from central Saudi Arabia

Eucalyptus is a fragrant plant with a highly volatile oil content grown worldwide. This study investigated the phytochemical and biological features of two Eucalyptus species, E. camaldulensis and E. globulus, cultivated in Central Saudi Arabia. Phytochemical analysis revealed 17 compounds in E. camaldulensis and 13 in E. globulus, with α-pinene and 1,8-cineole being both plants’ most abundant volatile components. The antimicrobial activity revealed that Salmonella typhimurium ATCC 13311 and Candida albicans ATCC 10231 are the most susceptible to E. camaldulensis, with the zone of inhibition diameters (ZIDs) of 17.0 ± 0.2 mm and 22.0 ± 0.3 mm, respectively. In contrast, for E. globulus, methicillin-resistant Staphylococcus aureus and Candida albicans ATCC 10231 were the most susceptible, with ZIDs of 13.0 ± 0.2 mm and 20.0 ± 0.2 mm, respectively. E. camaldulensis had minimum inhibitory concentration (MIC) range from 1.56 to 12.5 μL/mL, minimum biocidal concentration (MBC) range from 3.125 to 25.0 μL/mL, minimum biofilm inhibitory concentration (MBIC) range from 3.125 to 25.0 μL/mL, and minimum biofilm eradication concentration (MBEC) from 6.25 to 50.0 μL/mL, while E. globulus had MIC range from 3.125 to 12.5 μL/mL, MBC range from 6.25 to 25.0 μL/mL, MBIC range from 6.25 to 25.0 μL/mL, and MBEC range from 12.5 to 50.0 μL/mL, for the tested organisms. E. camaldulensis demonstrated better antimicrobial activity than E. globulus against the tested organisms, making it a promising antimicrobial drug candidate. Further research is required to determine its effectiveness in treating different human infections.

Green synthesis and characterization of silver nanoparticles from Ducrosia flabellifolia Boiss. aqueous extract: Anti-quorum sensing screening and antimicrobial activities against ESKAPE pathogens.

Biosynthesis of silver nanoparticles using natural compounds derived from plant kingdom is currently used as safe and low-cost technique for nanoparticles synthesis with important abilities to inhibit multidrug resistant microorganisms (MDR). ESKAPE pathogens, especially MDR ones, are widely spread in hospital and intensive care units. In the present study, AgNPs using Ducrosia flabellifolia aqueous extract were synthesized using a reduction method. The green synthesized D. flabellifolia-AgNPs were characterized by UV-Vis spectrophotometer, Scanning electron microscopy (SEM), and X-ray diffraction assays. The tested D. flabellifolia aqueous extract was tested for its chemical composition using Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (LC-ESI-MS). Anti-quorum sensing and anti-ESKAPE potential of D. flabellifolia-AgNPs was also performed. Results from LC-ESI-MS technique revealed the identification of chlorogenic acid, protocatechuic acid, ferulic acid, caffeic acid, 2,5-dihydroxybenzoic acid, and gallic acid as main phytoconstituents. Indeed, the characterization of newly synthetized D. flabellifolia-AgNPs revealed spherical shape with mean particle size about 16.961±2.914 nm. Bio-reduction of silver was confirmed by the maximum surface plasmon resonance of D. flabellifolia-AgNPs at 430 nm. Newly synthetized D. flabellifolia-AgNPs were found to possess important anti-ESKAPE activity with low minimal inhibitory concentrations (MICs) ranging from 0.078 to 0.312 mg/mL, and low minimal bactericidal concentrations (MBCs) varying from 0.312 to 0.625 mg/mL. Moreover, D. flabellifolia-AgNPs were active against Candida utilis ATCC 9255, C. tropicalis ATCC 1362, and C. albicans ATCC 20402 with high mean diameter of growth inhibition at 5 mg/mL, low MICs, and minimal fungicidal concentrations values (MFCs). The newly synthetized D. flabellifolia-AgNPs were able to inhibit violacein production in Chromobacterium violaceum, pyocyanin in Pseudomonas aeruginosa starter strains. Hence, the newly synthesized silver nanoparticles using D. flabellifolia aqueous extract can be used as an effective alternative to combat ESKAPE microorganisms. These silver nanoparticles can attenuate virulence of Gram-negative bacteria by interfering with the quorum sensing system and inhibiting cell-to-cell communication.

Resistance of a mixed bacterial culture isolated from bee dysbiosis to disinfectant in laboratory conditions

Disinfection is one of the components of preventive actions to prevent disease in animals by infectious agents. Through the elimination of agents of infectious diseases in the environment, it is able to interrupt the mechanisms of the epizootic process. For the development of beekeeping and obtaining quality and products, it is necessary to carry out activities in apiaries, which include disinfection. The introduction of new disinfectants in the field is possible after preliminary laboratory tests. The aim of our research objective to investigate the resistance of a mixed bacterial culture isolated from bees with the symptoms of dysbiosis to disinfectant under laboratory conditions. Bacteriological investigations carried out in Petri dishes using meat-peptone agar and Mueller-Hinton agar. The disinfectant diluted with distilled water at concentrations of 0.25 %, 0.5 %, 1,25 % and 2,5 %. On the Mueller Hinton agar, the bacterial elimination zones recorded at 1.25 % (11,6 ± 0,45 mm) and 2.5 % (12,4 ± 0,27 mm) concentration of disinfectant at 1 day of investigation, and 7,4 ± 0,27 mm (1,25 %), 11,2 ± 0,42 mm (2.5 %) at 72 hours of the experiment, respectively. In addition, the bacterial growth inhibition effect increased with experimental time and ranged from 24.0 ± 0.35 mm (0.5 %) to 28.2 ± 0.22 mm (2.5 %) on day 3 of the study. Bacteriostatic and bactericidal effects appeared to be less pronounced on meat-peptone agar. The highest diameters of inhibition of the processes of reproduction and development of microorganisms from mixed microbial association on this medium were recorded at 1.25 % and 2.5 % concentrations of the disinfectant at the 3rd day of the investigation with diameters of the zones of inhibition of growth 15.6 ± 0.45 mm and 26.4 ± 0.27 mm, respectively. The specificity of diffusion of the investigated active substance from the discs into the agar medium thickness was also noted. This effect has a varying effect on infectious agents in in vitro experiments. Thus bacteriological laboratory experiments should be performed on several culture media in purpose of obtaining accurate results. The analysis of the obtained results indicates the demonstration of antimicrobial effect of the investigated disinfectant against mixed bacterial culture in the form of bactericidal and bacteriostatic actions. Therefore, a promising direction of research for veterinary doctors and apiary business owners is the search for effective and efficient disinfectants. Laboratory investigation of the activity of a remedy are the first step before it is approbation.

FORMULATION AND ANTIBACTERIAL ACTIVITY OF HERBAL TOOTHPASTE BASED ON ACEH TRADITIONAL MEDICINE

This research is based on Acehnese traditional medicine containing betel leaf, areca nut, kencur rhizome, gambier sap, and clove buds. Traditionally, all parts of the plant are wrapped in betel leaf folds and chewed to maintain oral health. This study aimed to incorporate these ingredients into an herbal toothpaste and test its efficacy against bacteria that cause tooth decay, such as S. mutans and E. faecalis. Extracts from betel leaf, areca nut, aromatic ginger, gambier sap, and clove buds were used in this study. Based on variations in extract concentrations, three formulations were developed: F1, F2, and F3. In addition, F0 was the toothpaste base. The herbal toothpaste was light brown in color, homogeneous, semisolid, and had a characteristic betel leaf aroma, according to the evaluation results. The final product had a pH of 7.52–8.59, viscosity of 238.9–242.3 cP, and a foam height of 20 mm (F0), 11 mm (F1), 9 mm (F2), and 6 mm (F3). These values meet the toothpaste quality standard (SNI 112-3524-1995). While F1 showed moderate inhibition against S. mutans and E. faecalis in the antibacterial test, F2 and F3, showed high inhibition against S. mutans and moderate inhibition against E. faecalis. Based on these results, the optimal formula is F3 which has a larger inhibition diameter of 12.23 mm for S. mutans and 9.10 mm for E. faecalis. This herbal toothpaste can be developed to prevent oral candidiasis and gingivitis. Keywords: herbal toothpaste, antibacterial activity, Streptococcus mutans, Enterococcus faecalis

Phytochemicals properties and antimicrobial activities of Carica papaya and Balanites aegyptiaca’ seeds aqueous infusion and decoction extracts

Carica papaya and Balanites aegyptiaca seeds extract have several uses, from food to traditional medicine. This study aims to determine their phytochemicals compound and appreciate their antimicrobial properties against clinical strains. Polyphenolic content was determined with standard methods while DPPH radical scavenging activity is used to appreciate the antioxidant properties, using ascorbic acid as standard. Antimicrobial activities were performed according to the inhibition diameters, using agar diffusion method. Minimum inhibitory concentrations and Minimum fungicidal concentrations were established based on broth dilution methods. The extraction yield is ranged between 6.3 and 20.3%. The results shown polyphenolic content varying from 1256.13±21.09 to 2315.81±53.52 µg GAE/100 mL for Carica papaya and from 303.98±0.93 to 948.06±3.23 µg GAE/100 mL for Balanites aegyptiaca while the antioxidant activity is ranged between 31.76±2.35 and 58.47±4.24 µg AEAC/100 mL for Carica papaya and from 29.80±0.32 to 78.44±2.81 µg AEAC/100 mL for Balanites aegyptiaca. Infusion’s extracts always have the highest values of polyphenols content and antioxidant activity than decoction extracts, be it papaya or balanites seeds. Neitheir flavonoids content nor antibacterial activity was found. The inhibition diameter varies from 14.5±0.5 to 40.5±0.5 mm for papaya seeds extracts and from 16.5±0.5 to 21.0±0.5 mm for balanites seeds extracts without a significative effect of mixture for both extracts. MICs vary from 11.71±0.1 to 75.0±0.0 mg. mL-1 for Carica papaya seeds extracts with 11.72±0.2 to 37.30±0.2 mg. mL-1 and 18.74±0.1 to 100±0.0 mg.mL-1 for Balanites aegyptiaca. Mixture extracts presented intermediaire values. Decoction extracts have lowest MICs values and infusion reveals itself to be the sweetable aqueous extraction techniques but the appropriate infusion time need to be highlight.
 Keywords: Carica papaya, Balanites aegyptiaca, Seeds extracts, Phytochemical, antifungal

Experiment to Demonstrate Pesticide-Induced Antimicrobial Resistance (AMR): An Emerging Health Threat.

Background Pesticides, including insecticides, herbicides, and fungicides, are essential for global food production, boosting crop yields, and preventing disease transmission. However, their excessive and improper use raises concerns about potential long-term consequences, affecting microbial ecosystems and fostering antimicrobial resistance. Materials and methods The objective of the study was to identify the effect of the pesticide compound (Imidacloprid17.1% w/w) on the ATCCEscherichia coli. An experiment was conducted on ATCCEscherichia coli27852. A 0.5 McFarland suspension of the strain was incubated in the presence of a pesticide compound (Imidacloprid17.1% w/w) at a dilution of 1:4, 1:8, and 1:16. at 370C. Antibiotic susceptibility for cefoxitin, ciprofloxacin, ceftazidime, amikacin, and imipenem was determined via the Kirby-Bauer disk diffusion test at intervals of 24 hours, 48 hours, seven days, and 21 days. The results were then compared to the standard zone of inhibition diameter for ATCCEscherichia coli27852 by Clinical and Laboratory Standards Institute (CLSI) guidelines. Results No bacterial growth was detected at pesticide dilutions of 1:1 and 1:2, indicating their inability to tolerate high pesticide concentrations. However, growth became evident at a 1:4 dilution and beyond, with mutants thriving within the inhibition zone. The experiment caused significant alterations in the inhibition zone sizes for all antibiotics, especially notable with imipenem, amikacin, and ceftazidime compared to the initial zone size for ATCCEscherichia coli27852. Conclusion Our study concludes that the pesticide (Imidacloprid 17.1% w/w) significantly influences antibiotic resistance, especially with carbapenems, aminoglycosides, and cephalosporins in the tested groups at various concentrations and durations of exposure.

The Effect of Chlorogenic Acid in Green Arabica Coffee Beans on the Activity of Staphylococcus aureus

Background: Gingivitis is a dental and oral health problem caused by the bacteria Staphylococcus aureus. This research utilized the antibacterial effect of the chlorogenic acid compound content of green Arabica coffee beans (Coffea arabica L.) on the activity of the Staphylococcus aureus bacteria. The aim of the research was to determine the effect of chlorogenic acid from green Arabica coffee beans and its inhibitory diameter on the activity of Staphylococcus aureus bacteria.
 Methods: The research method used was laboratory experimental with post-test only with a control group design. The research samples were green Arabica coffee bean extract with various concentrations of 25%, 50%, 75%, and 100%, which is compared to various concentrations of pure chlorogenic acid (95% Sigma-Aldrich). The chlorogenic acid content in the extract was analyzed with liquid chromatography LC-MS/MS. The large sample was determined using the Federer formula with a total sample size of 24 samples. The parameter measured was the diameter of the growth inhibition zone for Staphylococcus aureus bacteria. Data were analyzed statistically using One-way ANOVA and Post Hoc LSD, and the research results were shown in regression graphs.
 Results: The results of the analysis of chlorogenic acid content of green arabica coffee bean extract amounted to 4.29% The results of this study showed that the average diameter of the inhibition zone of green Arabica coffee bean extract with concentrations of 25%, 50%, 75% and 100% on the growth of Staphylococcus aureus bacteria was 7.65 ± 0.289 mm; 9.63 ± 0.550 mm, 10.50 ± 0.374 mm, and 12.75 ± 0.370 mm. Research shows that the higher the concentration of green Arabica coffee bean extract, the larger the diameter of the inhibition zone. 95% pure chlorogenic acid from Sigma-Aldrich displays an inhibition zone above 12.5%.
 Conclusion: Chlorogenic acid exerts a substantial inhibitory impact on the proliferation of Staphylococcus aureus bacteria.

Mycoplasma and Neisseria Prevalence in Asymptomatic Women and Investigation of their Susceptibility to Tamarindus indica and Syzygium aromaticum Aqueous Extracts

Neisseria and Mycoplasma are two prevalent bacteria in the female urogenital tract leading to gynecological infections and infertility. The aim of this study was to assess the antibacterial activity of Tamarindus indica and Syzygium aromaticum extracts against Neisseria and Mycoplasma isolates. It was a cross cectional study on 60 asymptomatic women at the Protestant and Regional Hospital of Ngaoundere. For this reason, a large consecutive sample of patients with several well-defined characteristics was assembled and urine and cervical-vaginal swab were collected using standard procedures. After being isolated on a specific medium, several strains of Neisseria and Mycoplasma were identified based on their morphological and biochemical characteristics. The antibacterial activity of the plant extracts was tested using the agar-well diffusion method. It was discovered that 70% of asymptomatic women had overall infection, with varying prevalence rates. The prevalence rates of Neisseria and Mycoplasma were 14.29% and 85.71% respectively. The aqueous extracts of Syzygium aromaticum against Neisseria produced inhibitory diameters of 43 mm, 40 mm and 32 mm at doses of 20 mg/mL, 10 mg/mL, and 5 mg/mL, respectively while, at the same doses, the aqueous extract of Tamarindus indica produced inhibitory diameters of 16 mm, 14 mm and 13 mm, respectively. The combined extract of Syzygium aromaticum and Tamarindus indica exhibits inhibitory diameters of 25, 23, and 30 mm at 20 mg/mL, 10 mg/mL, and 5 mg/mL, respectively. Syzygium aromaticum extract alone showed efficacy against Mycoplasma, with diameters of 16.5 mm, 13 mm and 10.5 mm at concentrations of 20 mg/mL, 10 mg/mL, and 5 mg/mL respectively. Inhibition diameters of 18 mm (for fosfomycin and ofloxacin), 22 mm (for chloramphenicol and ceftriaxone) and 26 mm (for levofloxacin) were found using Neisseria isolates. The only drugs that demonstrated efficacy against Mycoplasma were Minocycline and Josamycin. Given these findings, extracts of Syzygium aromaticum and Tamarindus indica can be investigated and used to treat infections caused by Niesseria and Mycoplasma.

In vitro and in silico Studies: Penicillin-Binding Protein 2a (PBP2a) Inhibition by Stigmasterol in Banyan Hanging Roots (Ficus benjamina L.) as Novel Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA)

The most common cause of nosocomial infection worldwide is caused by Gram-positive coccus bacteria or what we commonly call Methicillin-resistant Staphylococcus aureus (MRSA). This study aimed to find novel antimicrobial agents from the banyan tree (Ficus benjamina L.) hanging roots to treat MRSA. Docking experiment and well diffusion were used as in silico and in vitro experiments respectively to identify the potential of stigmasterol against MRSA. The data were analyzed statistically with one-way variance analysis (ANOVA), post-doc Tukey assay, correlation, and regression by SPSS Amos 24. In the in silico experiment, stigmasterol was strongly associated with penicillin-binding protein 2a (PBP2a) on the active side of LYS289. Thus, it had the potential to inhibit PBP2a. Disruption of cell walls, the release of cytoplasmic contents, and a decrease in the cellular volume of MRSA were caused by the inhibition of PBP2a. The well diffusion test results showed the inhibition zone in 50 - 100 μg/ml of stigmasterol against MRSA. The inhibition zone was in the range of 7.38 – 10.17 mm. The inhibition diameter indicated a significant difference with a p-value < 0.05. The results of statistical analyses indicate that stigmasterol is effective as an antimicrobial against MRSA. Stigmasterol has potential as a potential microbial agent for the therapy of MRSA.

Susceptibility of some Enterobacteriaceae isolated from 4 different aquatic environments in DR Congo (Central Africa), to Amoxicillin/Clavulanic acid and some 3rd generation Cephalosporins

Little is known about the variation of the antibiotic susceptibility of different bacterial strains of the same cells species, isolated from different aquatic environments. The present study aims to evaluate the susceptibility towards some 3rd generation cephalosporins (Ceftriaxon, Ceftazidim and Cefotaxim) and Amoxicillin/Clavulanic acid, of Enterobacteriaceae strains isolated from groundwater, stream, hospital wastewater and slaughterhouse wastewater. Enterobacteria species were isolated on Mac Conkey agar, then identified using enzymatic and MALDI-TOF MS system. The antimicrobial susceptibility was carried out using the disk diffusion method. The antibiotic minimum inhibitory concentrations (MICs) were carried using the VITEK®2 system. Bacterial species mostly identified were Klebsiella pneumoniae, Escherichia coli, Salmonella typhi and Ewingelia americana. The antibiotic inhibition diameters and the MICs varied depending on the antibiotics, bacterial species and type of aquatic environment hosting the microorganism. Relatively lower MICs were recorded with Cefotaxim against different bacteria in slaughterhouse wastewater, in river water and in well water. Antibiotic resistance was noted with all strains from hospital wastewater. Significant differences (P˂0.05) amongst antibiotic inhibition diameter was noted for K. pneumoniae and S. typhi in most cases. The relative variations in the action mechanisms amongst antibiotics and the intrinsic defense potential of each bacterial strain, as well as the potential influence of the physicochemical properties of each water medium, could partly be at the origin of the relative differences observed at the phenotypic level. It seems necessary to explore the diversity, similarities and differences amongst antibiotic resistance genes in these different types of aquatic biotopes.

Comparative Analysis of the Inhibitory Efficacy of 50% and 80% Concentrations of Rambutan Seed Extract (Nephelium lappaceum L.) on the Growth of Candida albicans

Introduction. Denture stomatitis is a prevalent issue among those who wear dentures, and it is caused by Candida albicans. Ketoconazole, an azole antifungal medication, is commonly employed to treat denture stomatitis. However, it is important to note that the usage of this agent might lead to hepatotoxicity and the development of resistance. The objective of the study was to assess the inhibitory efficacy of rambutan seed extract (Nephelium lappaecum L.) at concentrations of 50% and 80% on the proliferation of Candida albicans.
 Methods. This research employs a laboratory experiment using a design that includes a post-test only control group. The specimen is an uncontaminated culture isolation of Candida albicans. This study had four distinct groups: rambutan seed extract concentrations of 50% and 80%, a positive control group, and a negative control group. Each group was reproduced six times. Using digital calipers to measure the diameter of resistance. Upon completion of data collection, the acquired data was subsequently subjected to analysis utilizing one-way ANOVA and post hoc LSD statistical testing.
 Results. The research findings indicate that the average ± standard deviation inhibitory diameter of rambutan seed extract was 50%, 80%, and the positive control for the growth of Candida albicans was 8.68 ± 0.585; 12.38±0.505; 22.43 ± 0.809 mm, respectively. In contrast, the negative control (DMSO) did not exhibit any inhibitory effects. The one-way ANOVA test revealed a statistically significant difference in the mean inhibitory diameter of rambutan seed extract at concentrations of 50% and 80% on the growth of Candida albicans (p=0.000; p?0.05). The findings of the LSD post hoc test indicated a significant difference in inhibitory power between the 50% and 80% concentrations of rambutan seed extract, as well as between these concentrations and both the positive and negative controls. Additionally, there was a significant difference in the growth of Candida albicans between the 50% and 80% concentrations of rambutan seed extract (p?0.05).
 Conclusion. The research findings indicate that the extract derived from rambutan seeds effectively inhibits the development of Candida albicans. An 80% concentration is the optimal concentration for maximum effectiveness.

Green Synthesis of Silver Nanoparticles and Testing its Effectiveness in Inhibiting E. coli, Staphylococcus Aureus Isolated from Urinary Tract Infections of Pregnant Women

The aim of the study was to identify the E. coli and S. aureus bacteria isolated from pregnant women with urinary tract infections that silver nanoparticles derived from green leaves inhibited. The silver nanoparticles showed inhibitory activity against these two types by Well diffusion method. towards bacteria. The result of the inhibition diameters by Well diffusion method were (35,33,30,25) for E.coli and (37,34,28,23) for S.aureus bacteria at concentrations (10,7.5,5,2.5)% respectively through the absence of colony growth on the surface of Muller Hunton agar plates at those concentrations. The use of nanoparticles as a result of their effective properties in inhibiting bacteria, provided that there are no side effects that affect its work. To make silver nanoparticles in an eco-friendly manner—that is, without heating the plant extract and solution or utilizing chemical catalysts during the reaction—one milliliter of strawberry leaf extract and fifty milliliters of silver nitrate solution—prepared at a concentration of one millimeter at room temperature for one to eight hours—were combined. Using UV spectrophotometers, scanning electron microscopy (SEM), XRD, and FTIR, it was determined that the preparation had begun when the mixture's color intensity increased after each of these eight hours had gone. The absorbance at 378 nm was visible in the UV-VIS spectrum. According to the results of scanning electron microscopy, the produced silver nanoparticles ranged in size from 37.35 nm. The biological method of producing silver nanoparticles in this low-cost and eco-friendly manner has shown promising results in preventing the growth of bacteria isolated from wound infections.

Phytochemical profiling, antibacterial and antioxidant potential of different parts of invasive plant Sonchus wightianus DC

The aim of the present investigation was to elucidate the phytochemical characterisation, antimicrobial and antioxidant efficacies of methanol extracts of leaf, stem, and root parts of S. wightianus. The phytochemical characterisation by GC-MS analysis revealed the presence of different phytocompounds such as Lupenone (38.02% in leave extract), Leupeyl acetate (33.43% in root extract), 24- Noursa −3, 12- diene (27.16% stem extract). S. wightianus methanol extracts demonstrate IC50, 8.52 µg/ml, 7.72 µg/ml and 9.08 µg/ml using DPPH, FRAP and MCA scavenging assay, respectively. The antibacterial activity of different methanol extracts was evaluated against four microorganisms with a mean zone diameter of inhibition ranging from 13 to 19 mm. For quantitative phytochemical analysis, the highest Total Phenolic Content (TPC) and Total Flavonol Content (TFC-2) were found for steam methanol extract (321.7 mg GAE/g of dry extract, 162.4 mg QE/g of dry extract respectively).

Nanoemulsion and nanoencapsulation of a hydroethanolic extract of Nettle (Urtica dioica) and Wormwood (Artemisia absinthium): comparison of antibacterial and anticancer activity.

Introduction: Nanoemulsion and nanoencapsulation are attractive novel methods that can be used for incorporating active plant extracts in food preparations and pharmaceutical formulations. In the current study, we aimed to investigate the anticancer and antibacterial effects of hydroethanolic extracts of Nettle (NE), Wormwood (WE), and the combination of the two plants (CNWE), as well as their nanoemulsion forms (NN, NW, CNNW) and nanoencapsulation forms (CN, CW, and CCNW). Methods: The morphology and structure of the nanoemulsion and nanoencapsulation preparations were assessed utilizing dynamic light scattering (DLS) along with transmission electron microscopy (TEM). The antibacterial activity of the prepared formulations were assessed by determining minimum inhibitory concentration (MIC), zone of inhibition diameter, minimum bactericidal concentration (MBC), along with biofilm growth inhibition against Salmonaella typhimurium and Klebsiella. pneumoniae. The anticancer activity was evaluated via a MTT assay in the colon cancer cell line (HCT116). Results: The nanoemulsion and nanoencapsulation particle size varied between 10 and 50nm and 60 and 110nm, respectively. The MIC values were between 11.25 and 95µg/mL along with MBC values between 11.25 and 190µg/mL. The highest inhibition of biofilm formation was observed with CCNW against K. pneumoniae (∼78.5%) and S. typhimurium (∼73%). In descending order, the inhibition of biofilm formation was CCNW > CW > CN > CNNW > NN > NW > CNWE > NE > WE against the tested bacteria. The IC50 values for NE, WE, CNWE, NN, NW, CNNW, CN, CW, and CCNW were determined as 250, 170, 560, 380, 312, 370, 250, 420, and 700µg/mL, respectively. Exposure to a high concentration of NW resulted in a significantly lower HCT116 viability compared to other groups. Taken together, CNNW, and CCNW showed the highest antibacterial and anticancer activitiy. Discussion: Nanoemulsion and nanoencapsulation were effective ways to increase the antibacterial and anticancer activity of the extracts and could be used in the food and pharmaceutical industries.

Antibiotic resistance determination using Enterococcus faecium whole-genome sequences: a diagnostic accuracy study using genotypic and phenotypic data

DNA sequencing could become an alternative to invitro antibiotic susceptibility testing (AST) methods for determining antibiotic resistance by detecting genetic determinants associated with decreased antibiotic susceptibility. Here, we aimed to assess and improve the accuracy of antibiotic resistance determination from Enterococcus faecium genomes for diagnosis and surveillance purposes. In this retrospective diagnostic accuracy study, we first conducted a literature search in PubMed on Jan14,2021, to compile a catalogue of genes and mutations predictive of antibiotic resistance in E faecium. We then evaluated the diagnostic accuracy of this database to determine susceptibility to 12 different, clinically relevant antibiotics using a diverse population of 4382 E faecium isolates with available whole-genome sequences and invitro culture-based AST phenotypes. Isolates were obtained from various sources in 11 countries worldwide between 2000 and 2018. We included isolates tested with broth microdilution, Vitek 2, and disc diffusion, and antibiotics with at least 50 susceptible and 50 resistant isolates. Phenotypic resistance was derived from raw minimum inhibitory concentrations and measured inhibition diameters, and harmonised primarily using the breakpoints set by the European Committee on Antimicrobial Susceptibility Testing. A bioinformatics pipeline was developed to process raw sequencing reads, identify antibiotic resistance genetic determinants, and report genotypic resistance. We used our curated database, as well as ResFinder, AMRFinderPlus, and LRE-Finder, to assess the accuracy of genotypic predictions against phenotypic resistance. We curated a catalogue of 228 genetic markers involved in resistance to 12 antibiotics in E faecium. Very accurate genotypic predictions were obtained for ampicillin (sensitivity 99·7% [95% CI 99·5-99·9] and specificity 97·9% [95·8-99·0]), ciprofloxacin (98·0% [96·4-98·9] and 98·8% [95·9-99·7]), vancomycin (98·8% [98·3-99·2] and 98·8% [98·0-99·3]), andlinezolid resistance (after re-testing false negatives: 100·0% [90·8-100·0] and 98·3% [97·8-98·7]). High sensitivity was obtained for tetracycline (99·5% [99·1-99·7]), teicoplanin (98·9% [98·4-99·3]), and high-level resistance to aminoglycosides (97·7% [96·6-98·4] for streptomycin and 96·8% [95·8-97·5] for gentamicin), although at lower specificity (60-90%). Sensitivity was expectedly low for daptomycin (73·6% [65·1-80·6]) and tigecycline (38·3% [27·1-51·0]), for which the genetic basis of resistance is not fully characterised. Compared with other antibiotic resistance databases and bioinformatic tools, our curated database was similarly accurate at detecting resistance to ciprofloxacin and linezolid and high-level resistance to streptomycin and gentamicin, but had better sensitivity for detecting resistance to ampicillin, tigecycline, daptomycin, and quinupristin-dalfopristin, and better specificity for ampicillin, vancomycin, teicoplanin, and tetracycline resistance. In a validation dataset of 382 isolates, similar or improved diagnostic accuracies were also achieved. To our knowledge, this work represents the largest published evaluation to date of the accuracy of antibiotic susceptibility predictions from E faecium genomes. The results and resources will facilitate the adoption of whole-genome sequencing as a tool for the diagnosis and surveillance of antimicrobial resistance in E faecium. A complete characterisation of the genetic basis of resistance to last-line antibiotics, and the mechanisms mediating antibiotic resistance silencing, are needed to close the remaining sensitivity and specificity gaps in genotypic predictions. Wellcome Trust, UK Department of Health, British Society for Antimicrobial Chemotherapy, Academy of Medical Sciences and the Health Foundation, Medical Research Council Newton Fund, Vietnamese Ministry of Science and Technology, and European Society of Clinical Microbiology and Infectious Disease.

Cyclotides derived from Viola dalatensis Gagnep: A novel approach for enrichment and evaluation of antimicrobial activity

Cyclotides, plant-derived cysteine-rich peptides, exhibit a wide range of beneficial biological activities and possess exceptional structural stability. Cyclotides are commonly distributed throughout the Violaceae family. Viola dalatensis Gagnep, a Vietnamese species, has not been well studied, especially for cyclotides. This pioneering research explores cyclotides from V. dalatensis as antimicrobials. This study used a novel approach to enhance cyclotides after extraction. The approach combined 30% ammonium sulfate salt precipitation and RP-HPLC. A comprehensive analysis was performed to ascertain the overall protein content, flavonoids content, polyphenol content, and free radical scavenging capacity of compounds derived from V. dalatensis. Six known cyclotides were sequenced utilizing MS tandem. Semi-purified cyclotide mixtures (M1, M2, and M3) exhibited antibacterial efficacy against Bacillus subtilis (inhibitory diameters: 19.67–23.50 mm), Pseudomonas aeruginosa (22.17–23.50 mm), and Aspergillus flavus (14.67–21.33 mm). The enriched cyclotide precipitate from the stem extract demonstrated a minimum inhibitory concentration (MIC) of 0.08 mg/mL against P. aeruginosa, showcasing significant antibacterial effectiveness compared to the stem extract (MIC: 12.50 mg/mL). Considerable advancements have been achieved in the realm of cyclotides, specifically in their application as antimicrobial agents.

Selection of lactic acid bacteria from home-made sourdoughs for resistance to the main almond skin polyphenols

The aim of this research was to identify lactic acid bacteria (LAB) that could be used as starter strains in sourdough made with almond peel powder to create novel fermented functional bakery products. Physicochemical characteristics and LAB were analyzed from ten home-made sourdoughs used at the family level in western Sicily (Italy). The pH (3.57–4.80) and TTA (8.20–14.20 mL 0.1 N NaOH/10 g) were inversely correlated. LAB dominated all sourdoughs, and the highest cell densities (6.74–9.28 log cfu/g) were detected on the medium Sour Dough Bacteria, except for one sample. Among LAB groups, the lowest counts (4.92–6.19 log cfu/g) were obtained on M17 used for LAB cocci. Yeasts were lower than LAB from two to four orders of magnitude with values between 3.93 and 6.11 log cfu/g. Twenty strains belonging to the species Enterococcus gilvus, Fructilactobacillus sanfranciscensis, Lacticaseibacillus paracasei, Lactiplantibacillus pentosus, Lactiplantibacillus plantarum, Lactococcus lactis, Lentilactobacillus buchneri, Lentilactobacillus diolivorans, Leuconostoc citreum, Leuconostoc holzapfelii, Levilactobacillus brevis, Pediococcus pentosaceus, and Weissella cibaria were identified. Eleven out of the 20 strains identified showed the ability to grow in presence of 16 polyphenols characterizing the peel of almonds. Eight of these LAB strains dropped pH below 4.5 after 6–8 h of fermentation, and two strains showed a strong inhibitory effect against Listeria monocytogenes ATCC19114 with inhibition diameters around the wells >19 mm. Thus, all acidifying strains were selected to produce sourdough bakery goods enriched with almond skin powder.

Entomotherapy as an alternative treatment for diseases due to Gram-negative bacteria in Burkina Faso

Insects are known for their harmful effects. However, they also benefit humans, animals, plants, and ecosystems. Its beneficial uses include entomophagy and entomotherapy. This study aimed to evaluate the antibacterial activity of insect extracts against Gram-negative bacteria. Antibacterial activities of thirteen crude extracts of medicinal insects were tested against twelve Gram-negative bacteria by diffusion on agar. Imipenem was used as an antibiotic for positive control. The thirteen extracts acted differently against certain Gram-negative bacteria. The largest inhibition diameter was for extracts of Cirina butyrospermi and Mylabris variabilis against Pseudomonas aeruginosa ATCC27853 and Salmonella enteritidis ATCC13076, respectively. The diameters of inhibition obtained using imipenem against these same bacterial strains were 13.0 ± 0.0 mm and 22 ± 1.0 mm, respectively. The lowest inhibition diameter (7.5 ± 0.0 mm) was obtained using Anopheles gambiae extract against Salmonella Typhimurium ATCC14028. Imipenem was active on all strains tested. The highest values of the index multi-resistance to insect’s extracts were reported for Pseudomonas aeruginosa ATCC9027 and Serratia odorifera 652411. Overall, the results of this study confirmed the antibacterial activities of insects used by traditional health practitioners to treat different pathologies. Entomotherapy could be an alternative treatment for certain infectious pathologies caused by gram-negative bacteria.