Lowest Minimum Bactericidal Concentration Research Articles

The effects of varying ingredients combination and boiling time on total phenolic content, antioxidant activity, and antimicrobial properties of lemongrass-ginger tea

This study was aimed at exploring the effect of varying lemongrass-ginger combinations, and boiling time on total phenolic contents (TPC), antioxidant activity, and antimicrobial efficacy of lemongrass-ginger tea. Lemongrass-ginger tea was produced by varying the percentage of lemongrass (25 %, 50 %, and 75 %) and boiling times (5, 10, and 15 min). The antioxidant activity of the lemongrass-ginger tea samples was investigated using the DPPH and ABTS assays whereas the TPC was determined using the Folin-Ciocalteau method. The antimicrobial activities were investigated by measuring the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) of the tea against selected microorganisms, and its combinatory effects with antimicrobial drugs. The lemongrass-ginger combination and the boiling time significantly affected antioxidant potential, TPC, and antimicrobial activities. TPC measured ranged between 966.7 ± 90.20 to 1761.3 ± 81.70 μgGAE/g whereas DPPH antioxidant activities varied from 43.97 ± 14.99 % to 75.20 ± 8.55 %. The highest values of TPC and DPPH were 1761.3 ± 81.70 μgGAE/g and 75.20 ± 8.55 % and were recorded by 75 % lemongrass-ginger combination boiled for 15 min. Furthermore, differences in lemongrass-ginger combination and boiling times resulted in varying antimicrobial activities against the test microorganisms. The lowest MBC was recorded for 50 % lemongrass boiled for 10 min against C. albicans, 75 % lemongrass boiled for 15 min against K. pneumoniae and S. typhi, and 25 % lemongrass against E. coli. Additionally, varying ingredient proportions and boiling times affected the combinatory effect of the tea with antimicrobial drugs. However, the exact effect depends on the proportion of ingredients used and the boiling times.

Extract from Psidium guineense Sw leaves: An alternative against resistant strains of Staphylococcus aureus

Psidium guineense SW., commonly known as sour guava, is used in traditional medicine to address diverse health issues, such as inflammation, infections, and gastrointestinal disorders. Although previous research has highlighted the antimicrobial properties of the root extract and the antioxidant potential of its fruits, information regarding the activities associated with the leaf extract is lacking. The aim of the study was to use the traditional knowledge of the biological properties of P. guineense and investigate its antimicrobial activity, mechanism of action, synergistic effects, and antivirulence activity against Staphylococcus aureus. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined for S. aureus, including antibiotic-resistant isolates. The synergy between the extract and antibiotics was evaluated. A growth curve was constructed for S. aureus treated with the extract. The anti-hemolytic activity was assessed by inhibiting hemolysis in human blood, and the inhibition of staphyloxanthin (STX) was examined. The extract effectively inhibited all strains with MIC and MBC values ranging from 256 to 512 µg/mL and 512 to 1024 µg/mL, respectively. Antimicrobial synergy experiments demonstrated the enhanced effectiveness of antibiotics, especially ciprofloxacin, when combined with the P. guineense extract, especially with ciprofloxacin, resulting in complete synergy against all S. aureus strains. In growth curve tests, the extract inhibited growth at MIC of 256 µg/mL within 8 h and significantly delayed it at MIC/2 (128 µg/mL) within 12 h. In antivirulence tests, the extract effectively reduced hemolysis and STX production by S. aureus at MIC and MIC/2, indicating its potential as an antimicrobial agent with antivirulence properties. The extract effectively inhibited S. aureus, including drug-resistant strains with low MIC and MBC values, exhibiting strong antimicrobial and synergistic properties with antibiotics. also In addition, the extract accelerated recovery by limiting bacterial growth and exhibiting antivirulence capabilities, reducing the severe symptoms of S. aureus infections.

Isolation and characterization of Streptococcus agalactiae inducing mass mortalities in cultured Nile tilapia (Oreochromis niloticus) with trials for disease control using zinc oxide nanoparticles and ethanolic leaf extracts of some medicinal plants

BackgroundStreptococcus agalactiae (Group B streptococcus, GBS) induces a serious infection that can harm not only aquatic life but also humans and other animals. In a fish farm in southern Egypt, Nile tilapia (Oreochromis niloticus) has developed an epidemic with clinical symptoms resembling piscine streptococcosis.ResultsInitial microscopic inspection of the affected fish brain and kidney indicated the presence of Gram-positive cocci. S. agalactiae was effectively isolated and identified using nucleotide homology of the 16S rRNA and species-specific PCR. The partial 16S rRNA sequence was deposited in the GenBank database at the NCBI and given the accession number MW599202. Genotyping using RAPD analysis indicated that the isolates in the present study belonged to the same genotypes and had the same origin. The challenge test, via immersion (9.2 × 107, 9.2 × 106, and 9.2 × 105 CFU/ml for 1 h) or intraperitoneal injection (4.6 × 107, 4.6 × 106, and 4.6 × 105 CFU/fish), elicited clinical symptoms resembling those of naturally infected fish with a mortality rate as high as 80%. The ability to create a biofilm as one of the pathogen virulence factors was verified. Zinc oxide nanoparticles and the ethanolic leaf extracts of nine medicinal plants demonstrated considerable antibacterial activities against the tested S. agalactiae strain with low minimum bactericidal concentrations (MBC) and minimum inhibitory concentrations (MIC). The ethanolic leaf extracts from Lantana camara and Aberia caffra showed potent antibacterial activity with MBC values of 0.24 and 0.485 mg/ml, and MIC values of 0.12 & 0.24 mg/ml, respectively.ConclusionThis study isolated S. agalactiae from O. niloticus mortalities in a fish farm in Assiut, Egypt. The pathogen persists in fish environments and can escape through biofilm formation, suggesting it cannot be easily eliminated. However, promising findings were obtained with in vitro control employing zinc oxide nanoparticles and medicinal plant extracts. Nevertheless further in vivo research is needed.

Effects of Bacteriocin Extracted from Lactobacillus plantarum on Treatment-Resistant Escherichia coli Bacteria Isolated from Humans and Livestock

Background: Lactic acid bacteria (LAB) are among the most common probiotics and play a significant role in promoting health within the human intestinal microbiota. Their protective functions in the intestine include producing antimicrobial compounds, regulating the balance of the intestinal microbiome, and more. Objectives: This study aims to investigate the antimicrobial effects of bacteriocin extracted from Lactobacillus plantarum (L. plantarum) on Escherichia coli (E. coli) strains that cause treatment-resistant urinary tract infections (UTIs) in humans and mastitis in livestock. Methods: Twenty E. coli isolates were obtained from patients with UTIs and cows with mastitis. After culturing the samples on Eosin-methylene blue, McConkey agar, and blood agar, the strains were identified using biochemical tests. Bacteriocin produced by L. plantarum ATCC8014 was extracted, and its concentration was measured using the Bradford method. The antimicrobial effect of the bacteriocin was assessed using the broth microdilution method to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Additionally, the bacteriocin's antimicrobial activity was evaluated through three repetitions of disk diffusion and agar well diffusion methods. Results: The findings revealed that the MIC and MBC concentrations for all human and animal strains were 13.38 μg/mL and 26.76 μg/mL, respectively. Notably, two animal samples (No. 3 and No. 10) and one human sample (No. 6) showed lower MIC and MBC concentrations compared to the other samples and the standard E. coli sample. However, all strains were resistant to bacteriocin in the disk diffusion and agar well diffusion methods. Conclusions: The data indicate a high risk of increasing treatment-resistant E. coli strains in UTIs and livestock, which could pose a significant threat to public and animal health. Therefore, it is essential to further investigate the effects of different bacteriocins on these resistant strains, in conjunction with antibiotic therapies.

Jellein-I-conjugated gold nanoparticles: Insights into the antibacterial, antibiofilm activities against MRSA, and anticancer properties

Antimicrobial peptides (AMPs) and their conjugation with nanoparticles hold promise for targeting Methicillin-resistant Staphylococcus aureus (MRSA). In this study, Jellein-I peptide, with a cysteine at the C-terminus, was conjugated to gold nanoparticles (GNPs) to enhance its antibacterial, antibiofilm, and anticancer activities. The GNPs were synthesized and then conjugated to Jellein-I, forming Jellein-I-Cys-GNPs. The nanoparticles were characterized using UV–visible spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), and Fourier transform infrared (FTIR) spectroscopy. UV–visible spectroscopy, DLS, and TEM confirmed the formation of GNPs with an average size of 5.5 nm. The UV–visible spectroscopy and FTIR results indicated the presence of peptide functional groups on the surface of the GNPs. To assess antibacterial activity, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were performed against MRSA strains. The conjugated Jellein-I exhibited lower MIC and MBC values (94 μM) compared to the free peptide (512 μM) against both clinical and standard MRSA strains. Additionally, GNP-conjugated Jellein-I demonstrated antibiofilm activity, inhibiting and removing biofilms while reducing metabolic activity by more than 82 %, 44 %, and 72 %, respectively. Cell viability studies on rat dermal fibroblast (RDF) cells showed over 80 % viability across all treatment concentrations. Furthermore, a clonogenic assay on the metastatic melanoma cell line (A375) demonstrated that GNP-conjugated Jellein-I had significantly better anticancer effects than the free peptide, even at a concentration as low as 9 μM. Our findings suggest that the conjugation of Jellein-I-Cys to GNPs could be a promising formulation for enhancing the antibacterial, antibiofilm, and anticancer activities of peptides. Further in vivo studies may establish this new nanoformulation as a potential therapeutic candidate for MRSA infections and cancer treatment.

Exploring Cynara cardunculus L. by-products potential: Antioxidant and antimicrobial properties

Cynara cardunculus L. (cardoon), a perennial crop indigenous to the Mediterranean region, has gained recognition for its remarkable resilience to diverse weather conditions and its multifaceted applications across various industries, which includes the use of the flower as a vegetable rennet to produce some cheeses, as a source of biomass for energy, or its seed oil for human consumption, biodiesel, and animal feed. In some applications (e.g. biomass or seed production), when crop is harvested at the end of the growth cycle, the leaves remain as the main by-products, along with the flowers. In the context of a circular economy, the aim of this work was to undergone studies to determinate their biological properties (antioxidant and antimicrobial). Methanolic and ethanolic extracts of C. cardunculus L. (globe artichoke var. scolymus (L.) Fiori) and cultivated cardoon (var. altilis DC.)) leaves and flowers were characterised in terms of their polyphenol profile (total phenolic content (TPC), total flavonoid compounds (TFC), and ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry (UHPLC-ToF-MS)), antioxidant capacity (free radical DPPH inhibition system, β-carotene bleaching assay), and antimicrobial capacity (minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antifungal). In addition, the cultivated cardoon leaves extracts were assessed before and after they were dried in an oven with forced air circulation to evaluate if this treatment affected their bioactive profile. Chlorogenic acid, apigenin, and luteolin were the most quantified of a total of sixteen compounds identified by UHPLC-ToF-MS. Cultivated cardoon dry leaf extract presented the best antioxidant capacity for both methanolic (EC50 = 0.8 mg/mL, antioxidant activity coefficient (AAC) = 279.67) and ethanolic (EC50 = 2.1 mg/mL, AAC = 448.06) extracts, compared to the cardoon flower extracts and the globe artichoke leaf extracts. Dried cultivated cardoon leaf extracts presented higher antioxidant capacity than fresh cultivated cardoon leaf extracts, but a greater number of polyphenolic compounds were identified in fresh cultivated cardoon leaf extract. The Gram-positive bacteria were more sensitive to the activity of both ethanolic and methanolic extracts than the Gram-negative and cultivated cardoon dry leaf ethanolic extract presented lower MIC and MBC values (125–2000 µg/mL) for most of the tested microorganisms, thus showing higher antimicrobial activity. As for the cultivated cardoon leaf extracts, the dried leaf extracts exhibited better antimicrobial activity, with lower MIC values, than the fresh leaf extracts. The extracts only demonstrated a slight inhibition against the fungi Aspergillus fumigatus. In conclusion, studies performed indicate that dried leaves maintain their biological activities compared to fresh leaves, and that flowers present significant biological activity which suggests the great potential of the by-products of this crop as a source of active compounds in different industrial applications (e.g. food industry).

In vitro antibacterial effect of a nano-zinc oxide eugenol sealer alone and in combination with chitosan, propolis, and nanosilver on Enterococcus faecalis

ABSTRACT Background: This study aimed to assess the antibacterial effect of a nano-zinc oxide eugenol (nZOE) sealer alone and in combination with chitosan, propolis, and nanosilver on Enterococcus faecalis. Materials and Methods: In this in vitro, experimental study, nanosilver, chitosan, and propolis with 10wt%, 20wt%, and 60wt% concentrations, respectively, were added to nZOE sealer, and their antibacterial activity against E. faecalis was evaluated by agar diffusion and broth microdilution tests. The diameter of the growth inhibition zones was measured, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were calculated for all materials. Data were analyzed by t-test (alpha = 0.05). Results: The addition of nanosilver, chitosan, and propolis to nZOE did not change the diameter of growth inhibition zone in agar diffusion test. Propolis and eugenol alone showed the lowest MIC and MBC. Chitosan alone showed the highest MIC and MBC. Furthermore, nZOE showed lower MBC than micro-ZOE (P = 0.000). All groups containing nZOE showed the lowest MIC and MBC values. Conclusion: The addition of propolis to nZOE can enhance its antibacterial activity against E. faecalis in vitro.

Comparison of susceptibility of Pseudomonas aeruginosa isolated from keratitis to antibiotics and multipurpose disinfecting solutions

PurposeThis study aimed to assess the susceptibility of ocular isolates of Pseudomonas aeruginosa to two multi-purpose disinfectant solutions (MPDS) and to determine if there was a relationship with resistance to antibiotics. MethodsTwenty-three strains of P. aeruginosa isolated from microbial keratitis cases in Australia were utilized in this study. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of two commercially available MPDSs, Biotrue and cleadew MPS were determined. Additionally, the MIC of the strains to five antibiotics, ciprofloxacin, levofloxacin, gentamicin, ceftazidime, and imipenem, were analyzed. ResultsAll strains were susceptible to 100 % of each of the MPDS. However, when MPDSs were diluted, cleadew MPS had significantly lower median MIC (median = 12.5 vs 25; p = 0.00008) and MBC (median = 25 vs 50; p = 0.0027) compared to Biotrue. All tested strains were susceptible to levofloxacin and gentamicin. Susceptibility rates to ciprofloxacin, imipenem, and ceftazidime were 52.2 %, 30.4 %, and 91.3 %, respectively. There were no significant relations between MIC or MBC to either MPDS and resistance to the antibiotics (p≧0.23). ConclusionBoth MPDSs were active against P. aeruginosa isolated from microbial keratitis in Australia. However, after dilution, cleadew MPS remained active against P. aeruginosa at lower concentrations. Certain strains of P. aeruginosa were resistant to imipenem, ceftazidime or ciprofloxacin. The lack of association of susceptibility to MPDS and antibiotics suggest that resistance to one did not predispose to resistance to the other.

Effect of low concentrations of lactic acid and temperature on the expression of adhesion, invasion, and toxin-encoding genes of Campylobacter jejuni from poultry.

The consumption of contaminated poultry meat is considered as a significant route of campylobacteriosis transmission. Lactic acid is a disinfectant agent with bactericidal effects on Campylobacter spp. The purpose of this study was to assess the low concentrations of lactic acid effect and different temperatures on the transcriptomic responses of Campylobacter jejuni (C. jejuni) adhesion and virulence-associated genes including peb4, ciaB, cdtA, cdtB, and cdtC. The samples were incubated at 10°C and 22°C for 48 h upon exposure to 30% and 60% lactic acid. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of lactic acid was also determined. Then, gene expression was assessed using real-time polymerase chain reaction (RT-PCR). Lactic acid had lower MIC and MBC levels at lower temperature. The utilization of both levels of lactic acid significantly reduced the expression of peb4, ciaB, cdtB, and cdtC genes over 48 h of incubation at 22°C. However, no significant difference was found in the expression of the cdtA gene between 10 and 22°C at 30% lactic acid. These results highlight the potential of low-concentration lactic acid in the downregulation of adhesion and virulence-associated genes as well as reduction of C. jejuni pathogenicity.

Biosynthesis of bacteriocin BacZY05-silver nanoconjugates and evaluation of their antibacterial properties.

Bacteriocins are antimicrobial peptides produced by bacteria to prevent the growth of pathogens. Combining bacteriocins with metal nanoparticles, like silver nanoparticles (AgNPs), has developed into a viable strategy to get over bacteriocin limitations. In this study, bacteriocin BacZY05 was extracted from Bacillus subtilis ZY05 and purified using various techniques. The resulting purified bacteriocin was then combined with silver nanoparticles to form bacteriocin silver nanoconjugates (BacZY05-AgNPs). The physicochemical properties of the BacZY05-AgNPs were characterized using various analytical techniques. The mean diameter of the synthesized AgNPs was approximately 20-60nm with an oval or spherical shape. The antimicrobial activity of the BacZY05-AgNPs was evaluated against several indicator strains by their zone of inhibition (ZOI), using the agar well diffusion method. Compared to bacteriocin (ZOI- 13 to 20mm) and AgNPs (ZOI- 10-22mm) alone, the antibacterial activity data demonstrated a 1.3-1.5-fold increase in the activity of bacteriocin-nanoconjugates (ZOI- 22 to 26mm). For Staphylococcus aureus MTCC3103 and Klebsiella pneumoniae MTCC109, BacZY05-capped AgNPs exhibited the lowest minimum inhibitory concentration (MIC), measuring 10.93µg/mL. For Salmonella typhi NCIM2501, the MIC was 28.75µg/mL. The highest MIC value was 57.5µg/mL for Escherichia coli DH5α and Vibrio cholerae MTCC3909. With BacZY05-capped AgNPs, the lowest minimum bactericidal concentration (MBC) of 28.75µg/mL was observed for Staphylococcus aureus MTCC31003. In the cases of Salmonella typhi NCIM2501 and Klebsiella pneumoniae MTCC109 concentration was 57.5µg/mL. Vibrio cholerae MTCC3909 and Escherichia coli DH5α had the highest MBC values at 115µg/mL.

Engineered extracellular vesicles coated with an antimicrobial peptide for advanced control of bacterial sepsis.

Alarming sepsis-related mortality rates present significant challenges to healthcare services globally. Despite advances made in the field, there is still an urgent need to develop innovative approaches that could improve survival rates and reduce the overall cost of treatment for sepsis patients. Therefore, this study aimed to develop a novel multifunctional therapeutic agent for advanced control of bacterial sepsis. Extracellular vesicles (EVs) isolated from lipopolysaccharide (LPS) induced HepG2 (hepatocellular carcinoma cells) (iEV) displayed an average particle size of 171.63±2.77nm, a poly dispersion index (PDI) of 0.32±0.0, and a zeta potential (ZP) of -11.87±0.18mV. Compared to HepG2 EV, LPS induction significantly increases the EV protein concentration, PDI and ZP, reduces the average size and promotes cell proliferation and cytoprotective effects of the isolated EVs (iEVs) against LPS-induced cytotoxicity. Coating of iEV with a cationic antimicrobial peptide (AMP) to form PC-iEV slightly changed their physical properties and shifted their surface charge toward neutral values. This modification improved the antibacterial activity (2-fold lower minimum bactericidal concentration [MBC] values) and biocompatibility of the conjugated peptide while maintaining iEV cytoprotective and anti-inflammatory activities. Our findings indicate the superior anti-inflammatory and antibacterial dual activity of PC-iEV against pathogens associated with sepsis.

Inhalable solid lipid nanoparticles of levofloxacin for potential tuberculosis treatment

Delivering novel antimycobacterial agents through the pulmonary route using nanoparticle-based systems shows promise for treating diseases like tuberculosis. However, creating dry powder inhaler (DPI) with suitable aerodynamic characteristics while preserving nanostructure integrity and maintaining bioactivity until the active ingredient travels deeply into the lungs is a difficult challenge. We developed DPI formulations containing levofloxacin-loaded solid lipid nanoparticles (SLNs) via spray-drying technique with tailored aerosolization characteristics for effective inhalation therapy. A range of biophysical techniques, including transmission electron microscopy, confocal microscopy, and scanning electron microscopy were used to measure the morphologies and sizes of the spray-dried microparticles that explored both the geometric and aerodynamic properties. Spray drying substantially reduced the particle sizes of the SLNs while preserving their nanostructural integrity and enhancing aerosol dispersion with efficient mucus penetration. Despite a slower uptake rate compared to plain SLNs, the polyethylene glycol modified formulations exhibited enhanced cellular uptake in both A549 and NR8383 cell lines. The percent viability of Mycobacterium bovis had dropped to nearly 0 % by day 5 for both types of SLNs. Interestingly, the levofloxacin-loaded SLNs demonstrated a lower minimum bactericidal concentration (0.25 µg/mL) compared with pure levofloxacin (1 µg/mL), which indicated the formulations have potential as effective treatments for tuberculosis.

Synthesis, characterization, antibacterial efficacy, and Cytotoxicity of monoclinic KMg3(Al0.5B0.5)Si3O10F2: A novel material for anticariogenic applications

Fluorophlogopite is a well-known fluorosilicate glass-ceramic derivative known for its bioactivity, machinability and optimal mechanical properties. There is limited information regarding its antibacterial and biocompatible properties. This research paper presents the synthesis and characterization of a novel Boron-doped Fluorphlogopite [KMg3(Al0.5B0.5)Si3O10F2] aiming to improve its antibacterial properties intended for anticariogenic applications. The combustion synthesis method was employed, with oxalyl dihydrazide (ODH) (C2H6N4O2) serving as the fuel. X-ray Diffraction (XRD) analyses unveiled a monoclinic crystal system, showcasing a P21 space group, and an average crystallite size of approximately 28 nm. Morphological scrutiny divulged clustered, irregularly shaped, cluster-like structures. The energy gap was determined to be around 4.97 ± 0.0062 eV. Fourier-Transform Infrared (FTIR) spectroscopy depicted the presence of characteristic bonds. BET analysis indicated the presence of a large surface area and porous structure (mesopores), which may contribute to lower MIC and MBC values, enhancing antibacterial effectiveness. The antibacterial activity, evaluated via agar well diffusion, yielded an 8 mm zone of inhibition. Furthermore, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) against S mutans were determined to be 2 mg/ml and 16 mg/ml, respectively. The biocompatibility of the synthesized KMg3(Al0.5B0.5)Si3O10F2 was assessed through the MTT assay, indicating non-toxic behavior at a concentration of 12 μg/ml with 98 % cell viability, while showing moderate toxicity with 61 % viable cells at its highest concentration of 200 μg/ml.

An In Vitro Study to Evaluate the Antimicrobial Activity of a Zinc Citrate, Sodium Fluoride, Alum and Xylitol-Based Toothpaste Formulation.

Periodontitis is a prevalent condition significantly affecting oral health. Comorbid conditions, such as diabetes, can heighten the severity of periodontal disease and overall oral health. Therefore, to enhance oral health and manage comorbid conditions, comprehensive periodontal care is essential. This approach could involve using toothpaste containing antimicrobial ingredients in routine oral care. This paper presents the results of an in vitro study analysing the antimicrobial properties of the test formulation containing zinc citrate, alum, sodium fluoride, and xylitol-based toothpaste(Stolin-R).These ingredients work together to help in providing comprehensive oral care by controlling growth of bacteria majorly responsible for periodontal disease and thus maintaining optimal oral hygiene. To determine the antimicrobial properties of zinc citrate, alum, sodium fluoride, and xylitol-based toothpaste formulationagainst key periodontal pathogens through in vitro analyses. The antimicrobial efficacy of test formulationis evaluated through minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-dependent antibacterial assessment against key periodontal pathogens, including Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Streptococcus mutans, and Bacteroides fragilis. The test formulationdemonstrated potent antimicrobial effectiveness against Bacteroides fragilis, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Streptococcus mutans, and Tannerella forsythia, by exhibiting low MIC and MBC. Additionally, significant bacterial reduction, exceeding 99.99%, was observed within five minutes, emphasising its potential as an effective adjunct in combating periodontal infection. Zinc citrate, alum, sodium fluoride, and xylitol-based toothpaste formulation demonstrates significant antimicrobial activity against key periodontal pathogens, suggesting its potential as an effective agent for maintaining oral health and combating gingival infection.

In vitro Antibacterial Activity of Ethanolic Tanao Si Kan Dang RD1 (Cannabis sativa L.) Extracts Against Human Antibiotic-Resistant Bacteria.

<b>Background and Objective:</b> A new strain of cannabis, <i>Cannabis sativa</i> L. Tanao Si Kan Dang RD1, has been approved and registered by the Rajamangala University of Technology Isan, Thailand. The <i>C. sativa</i> is acknowledged for its medicinal properties which demonstrated various therapeutic properties, such as anti-cancer and antibacterial activities. This study aimed to investigate the antibacterial activity of ethanolic extracts from the stems and leaves of the Tanao Si Kan Dang RD1 strain against seven antibiotic-resistant bacteria. <b>Materials and Methods:</b> The primary antibacterial activity of ethanolic Tanao Si Kan Dang RD1 extracts were determined using the disc diffusion method, while the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined using the broth microdilution method. <b>Results:</b> The largest inhibition zone, measuring 12 mm, was observed in leaf extracts against <i>Pseudomonas aeruginosa</i> 101. The lowest MIC, at 0.78 mg/mL, was obtained from stem extracts against <i>Stenotrophomonas maltophilia</i>. The lowest MBCs, at 12.5 mg/mL, were observed in leaf extracts against <i>Enterococcus faecalis</i>, <i>Acinetobacter baumannii</i>, multidrug-resistant <i>Klebsiella</i> <i>pneumoniae</i>, <i>Stenotrophomonas maltophilia</i> and <i>Pseudomonas aeruginosa</i> 101 and stem extracts against <i>Acinetobacter baumannii</i>, multidrug-resistant <i>Klebsiella pneumoniae</i>, <i>Stenotrophomonas maltophilia</i> and <i>Pseudomonas aeruginosa</i> 101. <b>Conclusion:</b> This study presents a novel finding regarding the antibacterial activity of ethanolic extracts from the leaves and stems of Tanao Si Kan Dang RD1 against antibiotic-resistant bacteria. The potential application of these cannabis plant extracts in the development of antibiotics capable of combating antibiotic-resistant pathogenic bacteria represents a promising strategy to address a significant global health concern.

One-Pot Microfluidics to Engineer Chitosan Nanoparticles Conjugated with Antimicrobial Peptides Using "Photoclick" Chemistry: Validation Using the Gastric Bacterium Helicobacter pylori.

Surface bioconjugation of antimicrobial peptides (AMP) onto nanoparticles (AMP-NP) is a complex, multistep, and time-consuming task. Herein, a microfluidic system for the one-pot production of AMP-NP was developed. Norbornene-modified chitosan was used for NP production (NorChit-NP), and thiolated-AMP was grafted on their surface via thiol-norbornene "photoclick" chemistry over exposure of two parallel UV LEDs. The MSI-78A was the AMP selected due to its high activity against a high priority (level 2) antibiotic-resistant gastric pathogen: Helicobacter pylori (H. pylori). AMP-NP (113 ± 43 nm; zeta potential 14.3 ± 7 mV) were stable in gastric settings without a cross-linker (up to 5 days in pH 1.2) and bactericidal against two highly pathogenic H. pylori strains (1011 NP/mL with 96 μg/mL MSI-78A). Eradication was faster for H. pylori 26695 (30 min) than for H. pylori J99 (24 h), which was explained by the lower minimum bactericidal concentration of soluble MSI-78A for H. pylori 26695 (32 μg/mL) than for H. pylori J99 (128 μg/mL). AMP-NP was bactericidal by inducing H. pylori cell membrane alterations, intracellular reorganization, generation of extracellular vesicles, and leakage of cytoplasmic contents (transmission electron microscopy). Moreover, NP were not cytotoxic against two gastric cell lines (AGS and MKN74, ATCC) at bactericidal concentrations. Overall, the designed microfluidic setup is a greener, simpler, and faster approach than the conventional methods to obtain AMP-NP. This technology can be further explored for the bioconjugation of other thiolated-compounds.

Anti-bacterial Effects of Allium atroviolaceum Hydroalcoholic Extract on Oral Bacteria of Streptococcus viridans Groups

: In light of the escalating global concern over antibiotic resistance, this study aimed to evaluate the antimicrobial activity of the hydroalcoholic extract of Allium atroviolaceum and compare it with 0.2% chlorhexidine using the well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods against Streptococcus mitis (ATCC 6249), Streptococcus mutans (PTCC 16836), Streptococcus sanguinis (PTCC 1449), and Streptococcus salivarius (PTCC 1448). The well diffusion method revealed the inhibitory effect of the extract, with the highest activity observed against Streptococcus salivarius. Subsequently, MIC and MBC values were determined, indicating that the hydroalcoholic extract had MIC and MBC values of 3.12 mg/mL against Streptococcus sanguinis and 6.25 mg/mL against other strains (Streptococcus mitis, Streptococcus mutans, Streptococcus sanguinis, and Streptococcus salivarius). Chlorhexidine exhibited significantly lower MIC and MBC values of 0.0003%. Based on literature reviews, Allium species exhibit antimicrobial properties. The findings highlight the potential of Allium atroviolaceum extract as an alternative or complementary antimicrobial agent and warrant further investigation to identify its bioactive components and explore their mechanisms of action. This study contributes to understanding natural antimicrobial agents and their potential applications against bacterial infections.

Photocatalytic activity and synergistic antibacterial effects of PCN-222@AgNPs under visible light irradiation

Ag NPs were generated by reducing silver ions with sodium borohydride and then loaded into a zirconium-based MOF, PCN-222, resulting in a deep purple powder, PCN-222@AgNPs, which exhibited photocatalytic activity. The material was characterized and found to have Ag NPs uniformly dispersed in the pores of PCN-222, with a content of 6.0306%. PCN-222@AgNPs had rod-shaped structures of micrometer sizes with irregular spherical Ag NPs on their surfaces, as revealed by scanning electron microscopy and transmission electron microscopy. In experiments on Ag NPs release and reactive oxygen species (ROS) detection, PCN-222@AgNPs effectively released Ag NPs into an aqueous solution and promote ROS generation. Finally, the antibacterial activities of PCN-222@AgNPs against Escherichia coli and Staphylococcus aureus were assessed by in vitro experiments. Results indicated that PCN-222@AgNPs had lower minimum bactericidal concentration (MBC) compared to PCN-222 in both light and dark environments. The MBC further decreased under light conditions due to the enhanced photocatalytic performance of the composite material and the promotion of Ag NPs release by ROS. These findings demonstrate that PCN-222@AgNPs have synergistic antibacterial effects under visible light irradiation.

Antibacterial Activities and Chemical Compounds of Plantago lanceolata (Ribwort Plantain) and Plantago major (Broadleaf Plantain) Leaf Extracts

Background: Plantago lanceolata L. (ribwort plantain) and Plantago major L. (broadleaf plantain) are widely used in ethnobotanical studies and for treating various diseases. This study aims to investigate the antimicrobial activity and chemical compounds of these plants. Methods: The leaf extracts of P. lanceolata and P. major were fractioned using different solvents. The phytochemical screening was carried out by the gas chromatography-mass spectrometry (GC-MS) method. The antibacterial activity of extracts was assessed using the disc diffusion method, and the minimum inhibitory concentration (MIC) and the minimum bactericidal concentrations (MBC) were measured by microtiter-broth dilution method. Results: The dichloromethane leaf extract of P. lanceolata and P. major showed the highest antibacterial activity against Salmonella paratyphi (diameter of the inhibition zone: 18.83 and 20.00 mm, respectively) at 100 mg/mL concentration. The lowest MIC was related to dichloromethane extracts of both plants against S. paratyphi (500 µg/mL). The lowest MBC (1000 µg/mL) was related to the dichloromethane extract of P. major against S. paratyphi. The main compounds of P. lanceolata leaf extracts were bis(2-ethylhexyl) phthalate (41.96%), 1-methoxy-3-(2-hydroxyethyl)nonane (32.69%), bicyclo[3.1.1]heptane, 2,6,6-trimethyl- (1.alpha.,2.beta.,5.alpha.)- (10.45%), and cycloheptasiloxane tetradecamethyl- (27.96% and 31.33%). The main compounds of P. major leaf extracts were eicosane (23.62%), cyclohexasiloxane dodecamethyl- (18.21%), 1-methyl-3-n-propyl-2-pyrazolin-5-one (18.08%), cycloheptasiloxane tetradecamethyl- (33.85%), and 1,2-benzisothiazole-3-acetic acid, methyl ester (34.26%). Conclusion: Fractionation of the methanolic leaf extract of P. lanceolata and P. major can help better isolate active components from these plants. The antibacterial properties of the extracts of two plants may be due to the presence of antibacterial compounds detected in GC-MS.

Total Phenolic and Flavonoid Contents, and Preliminary Antioxidant, Xanthine Oxidase Inhibitory and Antibacterial Activities of Fruits of Lapsi (Choerospondias axillaris Roxb.), an Underutilized Wild Fruit of Nepal

Choerospondias axillaris Roxb. (Anacardiaceae) is a deciduous tree, native to Nepal and the Himalayan region, that can reach a maximum height of 20 m. The study aimed to assess the total phenol, flavonoid, and carbohydrate content, and preliminary antioxidant potency, xanthine oxidase inhibition, and antibacterial properties of C. axillaris fruits extracts. Ethyl acetate, acetone, methanol, and water were used as extraction solvents. The quantitative analysis showed that the extracts had total polyphenols (68.28 μg to 154.91 μg gallic acid equivalent/mg extract), flavonoids (41.72 to 283.84 μg quercetin equivalent/mg extract), and carbohydrates contents (67.26 µg to 269.96 µg glucose equivalent/mg extract). The acetone extract exhibited the highest antioxidant activity (IC50: 15.72 µg/mL) and potent inhibition of xanthine oxidase (IC50: 20.80 µg/mL) among the extracts. The acetone extract exhibited the strongest antibacterial efficacy against Staphylococcus aureus and Bacillus cereus with inhibition zones of 13.76 mm and 12.56 mm, respectively. It also had the lowest minimum bactericidal concentration (MBC: 0.78 mg/mL) and minimum inhibitory concentration (MIC: 0.52 mg/mL) against S. aureus. In conclusion, the C. axillaris fruit extracts showed potent antioxidant, xanthine oxidase inhibitory, and antibacterial activities, suggesting their potential for pharmaceutical and nutraceutical applications. Further research should focus on the identification of active compounds and in vivo analysis of pharmacological activities.