Antimicrobial Susceptibility of Francisella tularensis Isolates in the United States, 2009-2018.

Francisella tularensis is the causative agent of tularemia. We tested the susceptibility of 278 F. tularensis isolates from the United States received during 2009-2018 to 8 antimicrobial drugs (ciprofloxacin, levofloxacin, doxycycline, tetracycline, gentamicin, streptomycin, chloramphenicol, and erythromycin). All isolates were susceptible to all tested drugs.

Evaluation of commercial, customized microdilution plates for Ureaplasma parvum, Ureaplasma urealyticum, and Mycoplasma hominis antimicrobial susceptibility testing and determination of antimicrobial resistance prevalence in France.

Antimicrobial susceptibility testing (AST) of human mycoplasmas using microdilution is time-consuming. In this study, we compared the performance of MICRONAUT-S plates (Biocentric-Bruker) designed for AST of Ureaplasma parvum, Ureaplasma urealyticum, and Mycoplasma hominis with the results using the Clinical & Laboratory Standards Institute (CLSI) reference method. Then, we investigated the prevalence and mechanisms of resistance to tetracyclines, fluoroquinolones, and macrolides in France in 2020 and 2021. The two methods were compared using 60 strains. For the resistance prevalence study, U. parvum-, U. urealyticum-, and M. hominis-positive clinical specimens were collected for 1 month each year in 22 French diagnostic laboratories. MICs were determined using the MICRONAUT-S plates. The tet(M) gene was screened using PCR, and fluoroquinolone resistance-associated mutations were screened using PCR and Sanger sequencing. Comparing the methods, 99.5% (679/680) MICs obtained using the MICRONAUT-S plates concurred with those obtained using the CLSI reference method. For 90 M. hominis isolates, the tetracycline, levofloxacin, and moxifloxacin resistance rates were 11.1%, 2.2%, and 2.2%, respectively, with no clindamycin resistance. For 248 U. parvum isolates, the levofloxacin and moxifloxacin resistance rates were 5.2% and 0.8%, respectively; they were 2.9% and 1.5% in 68 U. urealyticum isolates. Tetracycline resistance in U. urealyticum (11.8%) was significantly (P < 0.001) higher than in U. parvum (1.2%). No macrolide resistance was observed. Overall, the customized MICRONAUT-S plates are a reliable, convenient tool for AST of human mycoplasmas. Tetracycline and fluoroquinolone resistance remain limited in France. However, the prevalence of levofloxacin and moxifloxacin resistance has increased significantly in Ureaplasma spp. from 2010 to 2015 and requires monitoring. IMPORTANCE: Antimicrobial susceptibility testing of human urogenital mycoplasmas using the CLSI reference broth microdilution method is time-consuming and requires the laborious preparation of antimicrobial stock solutions. Here, we validated the use of reliable, convenient plates designed for antimicrobial susceptibility testing that allows the simultaneous determination of the MICs of eight antibiotics of interest. We then investigated the prevalence and mechanisms of resistance of each of these bacteria to tetracyclines, fluoroquinolones, and macrolides in France in 2020 and 2021. We showed that the prevalence of levofloxacin and moxifloxacin resistance has increased significantly in Ureaplasma spp. from 2010 to 2015 and requires ongoing monitoring.

Synthesis and characterization of marine seagrass (Cymodocea serrulata) mediated titanium dioxide nanoparticles for antibacterial, antibiofilm and antioxidant properties.

Cymodocea serrulata mediated titanium dioxide nanoparticles (TiO2 NPs) were successfully synthesized. The XRD pattern and FTIR spectra demonstrated the crystalline structure of TiO2 NPs and the presence of phenols, flavonoids and alkaloids in the extract. Further SEM revealed that TiO2 NPs has uniform structure and spherical in shape with their size ranged from 58 to 117 nm. Antibacterial activity of TiO2 NPs against methicillin-resistant Staphylococcus aureus (MRSA) and Vibrio cholerae (V. cholerae), provided the zone of inhibition of 33.9 ± 1.7 and 36.3 ± 1.9 mm, respectively at 100 µg/mL concentration. MIC of TiO2 NPs against MRSA and V. cholerae showed 84% and 87% inhibition at 180 µg/mL and 160 µg/mL respectively. Subsequently, the sub-MIC of V. cholerae demonstrated minimal or no impact on bacterial growth at concentration of 42.5 µg/mL concentration. In addition, TiO2 NPs exhibited their ability to inhibit the biofilm forming V. cholerae which caused distinct morphological and intercellular damages analysed using CLSM and TEM. The antioxidant properties of TiO2 NPs were demonstrated through TAA and DPPH assays and exposed its scavenging activity with IC50 value of 36.42 and 68.85 µg/mL which denotes its valuable antioxidant properties with potential health benefits. Importantly, the brine shrimp based lethality experiment yielded a low cytotoxic effect with 13% mortality at 100 µg/mL. In conclusion, the multifaceted attributes of C. serrulata mediated TiO2 NPs encompassed the antibacterial, antioxidant and anti-biofilm inhibition effects with low cytotoxicity in nature were highlighted in this study and proved the bioderived TiO2 NPs could be used as a promising agent for biomedical applications.

Clinical characteristics and antimicrobial susceptibility of Fusobacterium species isolated over 10 years at a Japanese university hospital.

PURPOSE: Anaerobic bacteria, existing on human skin and mucous membranes, can cause severe infections with complications or mortality. We examined the clinical characteristics of patients infected with Fusobacterium spp. and assessed their antibiotic susceptibility. METHODS: Clinical data were collated from patients diagnosed with Fusobacterium infections in a Japanese university hospital between 2014 and 2023. Antibiotic susceptibility tests were conducted following the Clinical and Laboratory Standards Institute guidelines. RESULTS: We identified 299 Fusobacterium isolates. The median age was 61 years (range, 14-95 years), with females constituting 43.1% of the patients. Most infections were community-acquired (84.6%, 253/299). Multiple bacterial strains were isolated simultaneously in 74.6% of cases. One-fourth of the patients had solid organ malignancies (25.4%, 76/299), and 14.5% (11/76) of those had colorectal cancer. The 30-day mortality rate was 1.3%. Fusobacterium species were isolated from blood cultures in 6% (18/299) of the patients. Patients, aged 75 years or older, with cerebrovascular disease or hematologic malignancy exhibited significantly higher prevalence of blood culture isolates in univariate analysis. Each Fusobacterium species had its characteristic infection site. Approximately 5% F. nucleatum and F. necrophorum isolates showed penicillin G resistance. Moxifloxacin resistance was observed in varying degrees across strains, ranging from 4.6 to 100% of isolates. All isolates were sensitive to ß-lactam/ß-lactamase inhibitors, carbapenems, and metronidazole. CONCLUSION: We show a link between Fusobacterium species and solid organ malignancies. We observed resistance to penicillin, cefmetazole, clindamycin, and moxifloxacin, warranting caution in their clinical use. This study offers valuable insights for managing Fusobacterium infections and guiding empirical treatments.

Biosurfactant-capped CuO nanoparticles coated cotton/polypropylene fabrics toward antimicrobial textile applications.

The global COVID-19 pandemic has led to an increase in the importance of implementing effective measures to prevent the spread of microorganisms. Consequently, there is a growing demand for antimicrobial materials, specifically antimicrobial textiles and face masks, because of the surge in diseases caused by bacteria and viruses like SARS-CoV-2. Face masks that possess built-in antibacterial properties can rapidly deactivate microorganisms, enabling reuse and reducing the incidence of illnesses. Among the numerous types of inorganic nanomaterials, copper oxide nanoparticles (CuO NPs) have been identified as cost-effective and highly efficient antimicrobial agents for inactivating microbes. Furthermore, biosurfactants have recently been recognized for their potential antimicrobial effects, in addition to inorganic nanoparticles. Therefore, this research's primary focus is synthesizing biosurfactant-mediated CuO NPs, integrating them into natural and synthetic fabrics such as cotton and polypropylene and evaluating the resulting fabrics' antimicrobial activity. Using rhamnolipid (RL) as a biosurfactant and employing a hydrothermal method with a pH range of 9-11, RL-capped CuO NPs are synthesized (RL-CuO NPs). To assess their effectiveness against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) microorganisms, the RL-CuO NPs are subjected to antibacterial testing. The RL-capped CuO NPs exhibited antimicrobial activity at much lower concentrations than the individual RL, CuO. RL-CuO NPs have shown a minimum inhibitory concentration (MIC) of 1.2 mg ml-1and minimum bactericidal concentration (MBC) of 1.6 mg ml-1forE. coliand a MIC of 0.8 mg ml-1and a MBC of 1.2 mg ml-1forS. aureus, respectively. Furthermore, the developed RL-CuO NPs are incorporated into cotton and polypropylene fabrics using a screen-printing technique. Subsequently, the antimicrobial activity of the coated fabrics is evaluated, revealing that RL-CuO NPs coated fabrics exhibited remarkable antibacterial properties against both gram-positive and gram-negative bacteria.

Pyrimidine-based sulfonamides and acetamides as potent antimicrobial Agents: Synthesis, Computational Studies, and biological assessment.

A series of novel sulfonamide and acetamide derivatives of pyrimidine were synthesized and their antimicrobial activities were assessed. Based on the Microbroth dilution method, the minimum inhibitory concentration (MIC) of the synthesized compounds demonstrated moderate to good levels of antifungal and antibacterial activity. Structure-activity relationship analysis suggested that the presence of electron-withdrawing groups, such as halogens, nitrile, and nitro groups, on the pyrimidine ring contributed to the enhanced antimicrobial potency, while electron-donating substituents led to a decrease in activity. Computational studies, including density functional theory (DFT), frontier molecular orbitals (FMO), and molecular electrostatic potential (MEP) analysis, provided insights into the electronic properties and charge distribution of the compounds. Drug-likeness evaluation using ADME/Tox analysis indicated that the synthesized compounds possess favorable physicochemical properties and could be potential drug candidates. Molecular docking against the Mycobacterium TB protein tyrosine phosphatase B (MtbPtpB) revealed that the synthesized compounds exhibited strong binding affinities (-46 kcal/mol to - 61 kcal/mol) and formed stable protein-ligand complexes through hydrogen bonding and π-π stacking interactions with key residues in the active site. The observed interactions from the docking simulations were consistent with the predicted interaction sites identified in the FMO and MEP analyses. These findings suggest that the synthesized pyrimidine derivatives could serve as promising antimicrobial agents and warrant further investigation for drug development.

Fourth national Japanese antimicrobial susceptibility pattern surveillance program: Bacterial isolates from patients with complicated urinary tract infections.

INTRODUCTION: Antimicrobial susceptibility patterns of bacterial pathogens isolated from patients with complicated urinary tract infections were analyzed using the national surveillance data, comprising 793 bacterial strains from eight clinically relevant species. MATERIALS AND METHODS: Data were collected for the fourth national surveillance project from July 2020 to December 2021 by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Disease, and the Japanese Society of Clinical Microbiology. Surveillance was supervised with the cooperation of 43 medical institutions throughout Japan. RESULTS: Fluoroquinolone required a minimum inhibitory concentration (MIC) of 2-64 mg/L to inhibit the 330 tested Escherichia coli strains. The proportion of levofloxacin-resistant E. coli strains increased from 28.6% in 2008 to 29.6% in 2011, 38.5% in 2015, and 44.5% in 2021. The proportion of levofloxacin-resistant strains of Pseudomonas aeruginosa also increased from previous survey results, showing a continuing downward trend. Conversely, the proportion of levofloxacin-resistant strains of Enterococcus faecalis decreased relative to previous reports. Neither multidrug-resistant P. aeruginosa nor carbapenem-resistant Enterobacteriaceae were detected. For methicillin-resistant Staphylococcus aureus (MRSA), the proportion of vancomycin-susceptible strains (MIC of 2 µg/mL) decreased from 14.7% to 7.7%. DISCUSSION: Bacterial strains that produced extended-spectrum ß-lactamase included E. coli (82/330 strains, 24.8%), Klebsiella pneumoniae (11/68 strains, 16.2%), and Proteus mirabilis (4/26 strains, 15.4%). As compared to previous surveillance reports, these strains showed an increase in proportion over the years.

Agreement of methods to assess antimicrobial susceptibility using Escherichia coli isolates as target models.

Antimicrobial susceptibility tests (AST) conducted in vitro offer a range of methods to assess the antimicrobial resistance (AMR) of microorganisms. Escherichia coli, a widely distributed bacterium, is closely linked to the issue of AMR. In this way, the present study aimed to assess the agreement among different in vitro AST methods, including disk diffusion in agar, broth dilution, and agar dilution method. A total of 100 E. coli isolates were analyzed for their resistance levels against six antibiotics: amoxicillin, ceftiofur, ciprofloxacin, chloramphenicol, tetracycline, and sulfamethoxazole + trimethoprim, using the aforementioned AST methods. Standard breakpoint values were employed to classify isolates as resistant, intermediate, or susceptible, and comparisons among the AST methods were conducted by McNemar's test (P < .05). The obtained data demonstrated equivalence among the AST methods, highlighting the reliability of these standardized classical methodologies. This standardization aids in preventing the inappropriate use of antimicrobials and the dissemination of antimicrobial-resistant microorganisms.

Effects of UV/H2O2 Degradation on the Physicochemical and Antibacterial Properties of Fucoidan.

The applications of fucoidan in the food industry were limited due to its high molecular weight and low solubility. Moderate degradation was required to depolymerize fucoidan. A few studies have reported that fucoidan has potential antibacterial activity, but its antibacterial mechanism needs further investigation. In this study, the degraded fucoidans were obtained after ultraviolet/hydrogen peroxide treatment (UV/H2O2) at different times. Their physicochemical properties and antibacterial activities against Staphylococcus aureus and Escherichia coli were investigated. The results showed that the average molecular weights of degraded fucoidans were significantly decreased (up to 22.04 times). They were mainly composed of fucose, galactose, and some glucuronic acid. Fucoidan degraded for 90 min (DFuc-90) showed the strongest antibacterial activities against Staphylococcus aureus and Escherichia coli, with inhibition zones of 27.70 + 0.84 mm and 9.25 + 0.61 mm, respectively. The minimum inhibitory concentrations (MIC) were 8 mg/mL and 4 mg/mL, respectively. DFuc-90 could inhibit the bacteria by damaging the cell wall, accumulating intracellular reactive oxygen species, reducing adenosine triphosphate synthesis, and inhibiting bacterial metabolic activity. Therefore, UV/H2O2 treatment could effectively degrade fucoidan and enhance its antibacterial activity.

The Cd resistant mechanism of Proteus mirabilis Ch8 through immobilizing and detoxifying.

Cadmium (Cd) pollution is a serious global environmental problem, which requires a global concern and practical solutions. Microbial remediation has received widespread attention owing to advantages, such as environmental friendliness and soil amelioration. However, Cd toxicity also severely deteriorates the remediation performance of functional microorganisms. Analyzing the mechanism of bacterial resistance to Cd stress will be beneficial for the application of Cd remediation. In this study, the bacteria strain, up to 1400 mg/L Cd resistance, was employed and identified as Proteus mirabilis Ch8 (Ch8) through whole genome sequence analyses. The results indicated that the multiple pathways of immobilizing and detoxifying Cd maintained the growth of Ch8 under Cd stress, which also possessed high Cd extracellular adsorption. Firstly, the changes in surface morphology and functional groups of Ch8 cells were observed under different Cd conditions through SEM-EDS and FTIR analyses. Under 100 mg/L Cd, Ch8 cells exhibited aggregation and less flagella; the Cd biosorption of Ch8 was predominately by secreting exopolysaccharides (EPS) and no significant change of functional groups. Under 500 mg/L Cd, Ch8 were present irregular polymers on the cell surface, some cells with wrapping around; the Cd biosorption capacity exhibited outstanding effects (38.80 mg/g), which was mainly immobilizing Cd by secreting and interacting with EPS. Then, Ch8 also significantly enhanced the antioxidant enzyme activity and the antioxidant substance content under different Cd conditions. The activities of SOD and CAT, GSH content of Ch8 under 500 mg/L Cd were significantly increased by 245.47%, 179.52%, and 241.81%, compared to normal condition. Additionally, Ch8 significantly induced the expression of Acr A and Tol C (the resistance-nodulation-division (RND) efflux pump), and some antioxidant genes (SodB, SodC, and Tpx) to reduce Cd damage. In particular, the markedly higher expression levels of SodB under Cd stress. The mechanism of Ch8 lays a foundation for its application in solving soil remediation.

Chemical Composition, Antioxidant, and Antibacterial Activity of Ruta chalepensis L. Ethanolic Extract.

Ruta chalepensis L. is a versatile herb used in culinary arts and traditional medicine. The study aimed to determine the chemical composition of an ethanolic extract from R. chalepensis and the total phenolic and flavonoid content. Additionally, the extracts' antimicrobial and antioxidant activities were tested. The disc diffusion method and minimum inhibitory concentration (MIC) were used to test the antibacterial properties on four types of bacteria: Escherichia coli, Proteus penneri, Bacillus cereus, and Staphylococcus aureus. A colorimetric assay was used to evaluate the total phenolic and flavonoid content, and the DPPH method was used to assess the antioxidant activity. The phytochemical constituents were determined using LC-MS/MS. The results indicated that R. chalepensis ethanolic extract had 34 compounds, and the predominant compounds were quercetin (9.2 %), myricetin (8.8 %), and camphene (8.0 %). Moreover, the extract had a good level of polyphenols and flavonoids, as demonstrated by inhibiting free radicals (DPPH) (IC50 was 41.2±0.1). Also, the extract exhibited robust antimicrobial activity against P. penneri and S. aureus with an MIC of 12.5 and 25.0 µg/mL, respectively. In conclusion, the results suggest that the R. chalepensis ethanolic extract has good antioxidant and antibacterial properties that could be utilized to develop new antibacterial agents.

In vitro Activity of Cefmetazole and Flomoxef among Extended-Spectrum Beta-Lactamase producing Enterobacterales.

In this age of antimicrobial resistance (AMR), improving treatment using existing antibiotics is desirable. Extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales (ESBL-E) are high priority AMR pathogens according to the World Health Organization. Cephamycin-class beta- lactams are tolerant to hydrolysis by ESBL activity and have bactericidal effects on ESBL-E. The aim of the present study was to compare the in vitro minimum inhibitory concentration (MIC) of cefmetazole (CMZ) and flomoxef (FMOX) among ESBL-E strains. This was a retrospective study using microbiology laboratory data from Okayama University Hospital (Japan) from January 2014 to June 2022. The MIC was determined by broth microdilution method and the ESBL phenotypes were determined by double-disk method. Antimicrobial use density (AUD) data for CMZ and FMOX were also gathered. Annual proportions of ESBL-producing organisms in Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae complex were 20.4-30.6%, 3.5-13.7%, and 0-3.1%, respectively. The ESBL-producing bacteria with MIC levels ≤1 µg/mL for CMZ and FMOX ranged from 57 to 84% and 97 to 100%, respectively, for E. coli, and from 50 to 92% and 80 to 100%, respectively, for K. pneumoniae. E. cloacae strains showed MIC levels ≥32 µg/mL for both agents. The AUD ratio for CMZ to FMOX ranged from 5.31 to 12.27, with no apparent upward or downward trend. Proportions of ESBL-producing E. coli and K. pneumoniae strains with MIC ≤1 µg/mL were greater in FMOX than in CMZ. To corroborate the clinical superiority of FMOX in treating ESBL-E infections, a randomized controlled study, as well as pharmacokinetic/pharmacodynamic analysis, is required.

Antibacterial activity in egg samples from small-spotted catshark Scyliorhinus canicula and nursehound Scyliorhinus stellaris: A preliminary investigation.

The study aims to identify antibacterial properties in unfertilized eggs of Scyliorhinus canicula and Scyliorhinus stellaris. Despite challenging marine conditions, these eggs retain their integrity for extended periods and remain unaffected by pathogens. The antibacterial activity was measured using minimum inhibitory and minimum bactericidal concentration analysis. The eggs of S. stellaris exhibited a slight inhibitory effect against Staphylococcus aureus and Listeria monocytogenes, whereas both species' eggs showed no activity against gram-negative microorganisms.

Antimicrobial Activity of Positively Charged Oligopeptides with Theoretical High α-Helix Content against Cutibacterium acnes.

Cutibacterium acnes is abundant and commonly exists as a superficial bacteria on human skin. Recently, the resistance of C. acnes to antimicrobial agents has become a serious concern, necessitating the development of alternative pharmaceutical products with antimicrobial activity against C. acnes. To address this need, we evaluated the antimicrobial activity of CKR-13-a mutant oligopeptide of FK-13 with increased net charge and theoretical α-helical content-against C. acnes in modified Gifu Anaerobic Medium broth by determining the minimum inhibitory concentration (MIC). CKR-13 exerted greater antimicrobial activity against C. acnes than FK-13 in the broth at pH 7.0. The antimicrobial activity of CKR-13 with RXM against C. albicans was pH-dependent. The ionization of CKR-13 and pH-dependent growth delay of C. albicans was suggested to be associated with the increase in CKR-13 antimicrobial activity.

Essential Oil Compounds in Combination with Conventional Antibiotics for Dermatology.

Antimicrobial resistance has emerged as a significant threat to public health, prompting novel combinations comprising of natural sources such as essential oil compounds with conventional antibiotics. This study aimed to determine the possible interactions between six essential oil compounds with eight antibiotics/antifungals against six pathogens (Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Acinetobacter baumannii, Cutibacterium acnes, and Candida albicans) commonly implicated in skin infections. The minimum inhibitory concentrations (MICs) for the antibiotics and essential oil compounds were evaluated singularly and in combination using the broth microdilution assay. The fractional inhibitory concentrations (FIC) were calculated to determine the interactive profile of the combinations. The synergistic interactions (FIC ≤ 0.5) were further analysed at varying ratios and depicted on isobolograms. The toxicity of the synergistic combinations was determined using the brine shrimp lethality assay. Eight synergistic interactions were identified against the selected Gram-positive and P. aeruginosa pathogens, and the combinations also demonstrated a reduced toxicity. The combination of amoxicillin and eugenol demonstrated the lowest toxicity (LC50 = 1081 µg/mL) and the highest selectivity index (14.41) when in a 70:30 ratio. This study provides insight into the in vitro antimicrobial interactions of essential oil compounds and conventional antibiotics that can form a basis for newer therapies.

1,3,6-Trigalloylglucose: A Novel Potent Anti-Helicobacter pylori Adhesion Agent Derived from Aqueous Extracts of Terminalia chebula Retz.

1,3,6-Trigalloylglucose is a natural compound that can be extracted from the aqueous extracts of ripe fruit of Terminalia chebula Retz, commonly known as "Haritaki". The potential anti-Helicobacter pylori (HP) activity of this compound has not been extensively studied or confirmed in scientific research. This compound was isolated using a semi-preparative liquid chromatography (LC) system and identified through Ultra-high-performance liquid chromatography-MS/MS (UPLC-MS/MS) and Nuclear Magnetic Resonance (NMR). Its role was evaluated using Minimum inhibitory concentration (MIC) assay and minimum bactericidal concentration (MBC) assay, scanning electron microscope (SEM), inhibiting kinetics curves, urea fast test, Cell Counting Kit-8 (CCK-8) assay, Western blot, and Griess Reagent System. Results showed that this compound effectively inhibits the growth of HP strain ATCC 700392, damages the HP structure, and suppresses the Cytotoxin-associated gene A (Cag A) protein, a crucial factor in HP infection. Importantly, it exhibits selective antimicrobial activity without impacting normal epithelial cells GES-1. In vitro studies have revealed that 1,3,6-Trigalloylglucose acts as an anti-adhesive agent, disrupting the adhesion of HP to host cells, a critical step in HP infection. These findings underscore the potential of 1,3,6-Trigalloylglucose as a targeted therapeutic agent against HP infections.

Cold maceration extraction of wild fruit Terminalia bellirica (Gaertn.) Roxb.: exploring its bioactives for biomedical applications.

Terminalia bellirica (T. bellirica) (Gaertn.) Roxb. is a well-known traditional medicinal plants that show promising treatment because of fewer side effects in humans. In the present study, the total phenol, flavonoid, condensed and hydrolyzable tannins extracted and analyzed from cold macerated (CM) T. bellirica (Gaertn.) Roxb. fruit (TBF) and leaves (TBL) extract with the identification of bioactive compounds using GC-MS/MS technique. The highest amount of bioactive content was found in ethanolic extract than toluene. Current experimental data of TBF extract shows the maximum and significant biological activity like free radical scavenging activity against DPPH and FRAP assays with IC50 values of 51.07 ± 0.52 µg/ml and 63.14 ± 0.59 µg/ml respectively. However, IC50 cytotoxicity values of TBF extract on MCF-7 cells for 24 hrs was found to be 6.34 ± 0.72 µg/ml. Minimum inhibitory concentration (MIC) for infectious pathogens Escherichia coli and Bacillus cereus was >12.5 µg/ml and >100 µg/ml respectively, however, anti-inflammatory activity was demonstrated as an IC50 value of 509.1 ± 1.72 µg/ml. Cold macerated fruit extract revealed threatening inhibitory potential against the α-amylase and α-glucosidase enzymes, with IC50 of 50.98 ± 0.23 µg/ml and 46.70 ± 1.38 µg/ml respectively. Finally, the outcome of this study showed that T. bellirica (Gaertn.) Roxb. fruit extract could be an effective source of bioactives with efficient biomedical properties.

Potential of microbial-derived biosurfactants for oral applications-a systematic review.

BACKGROUND: Biosurfactants are amphiphilic compounds produced by various microorganisms. Current research evaluates diverse types of biosurfactants against a range of oral pathogens. OBJECTIVES: This systematic review aims to explore the potential of microbial-derived biosurfactants for oral applications. METHODOLOGY: A systematic literature search was performed utilizing PubMed-MEDLINE, Scopus, and Web of Science databases with designated keywords. The results were registered in the PROSPERO database and conducted following the PRISMA checklist. Criteria for eligibility, guided by the PICOS framework, were established for both inclusion and exclusion criteria. The QUIN tool was used to assess the bias risk for in vitro dentistry studies. RESULTS: Among the initial 357 findings, ten studies were selected for further analysis. The outcomes of this systematic review reveal that both crude and purified forms of biosurfactants exhibit antimicrobial and antibiofilm properties against various oral pathogens. Noteworthy applications of biosurfactants in oral products include mouthwash, toothpaste, and implant coating. CONCLUSION: Biosurfactants have garnered considerable interest and demonstrated their potential for application in oral health. This is attributed to their surface-active properties, antiadhesive activity, biodegradability, and antimicrobial effectiveness against a variety of oral microorganisms, including bacteria and fungi.

Efficacy of a mouthwash containing ε-poly-L-lysine, funme peptides and domiphen in reducing halitosis and supragingival plaque: a randomized clinical trial.

OBJECTIVE: To evaluate the antibacterial effectiveness of a combination of ε-poly-L-lysine (ε-PL), funme peptide (FP) as well as domiphen against oral pathogens, and assess the efficacy of a BOP® mouthwash supplemented with this combination in reducing halitosis and supragingival plaque in a clinical trial. MATERIALS AND METHODS: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the compound against Fusobacterium nucleatum, Porphyromonas gingivalis, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans were determined by the gradient dilution method. Subsequently, the CCK-8 assay was used to detect the toxicity of mouthwash on human gingival fibroblastst, and the effectiveness in reducing halitosis and supragingival plaque of the mouthwash supplemented with the combination was analyzed by a randomized, double-blind, parallel-controlled clinical trial. RESULTS: The combination exhibited significant inhibitory effects on tested oral pathogens with the MIC < 1.56% (v/v) and the MBC < 3.13% (v/v), and the mouthwash containing this combination did not inhibit the viability of human gingival fibroblasts at the test concentrations. The clinical trial showed that the test group displayed notably lower volatile sulfur compounds (VSCs) at 0, 10, 24 h, and 7 d post-mouthwash (P < 0.05), compared with the baseline. After 7 days, the VSC levels of the and control groups were reduced by 50.27% and 32.12%, respectively, and notably cutting severe halitosis by 57.03% in the test group. Additionally, the Plaque Index (PLI) of the test and control group decreased by 54.55% and 8.38%, respectively, and there was a significant difference in PLI between the two groups after 7 days (P < 0.01). CONCLUSIONS: The combination of ε-PL, FP and domiphen demonstrated potent inhibitory and bactericidal effects against the tested oral pathogens, and the newly formulated mouthwash added with the combination exhibited anti-dental plaque and anti-halitosis properties in a clinical trial and was safe. TRIAL REGISTRATION: The randomized controlled clinical trial was registered on Chinese Clinical Trial Registry (No. ChiCTR2300073816, Date: 21/07/2023).

Biological Activities of Virgin Coconut and Virgin Olive Oil Mixture against Oral Primary Colonizers: An In Vitro Study.

AIM AND BACKGROUND: This study aimed to explore the potential synergistic interaction of virgin coconut oil (VCO) and virgin olive oil (VOO) mixture against Streptococcus sanguinis, Streptococcus mutans, and Lactobacillus casei in a single and mixture species through the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antiadherence, and antibiofilm activities. MATERIALS AND METHODS: The broth microdilution technique was used to individually determine the MIC of both oils and an oil mixture (in the ratio of 1:1) in a 96-well microtiter plate. As for the MBC, the subcultured method was used. The fractional inhibitory concentration index (ΣFIC) was determined to identify the interaction types between both oils. The oil mixture at its MIC was then tested on its antibiofilm and antiadherence effect. RESULTS: The MIC of the oil mixture against the tested microbiota was 50-100%. The oil mixture was bactericidal at 100% concentration for all the mentioned microbes except S. mutans. The ΣFIC value was 2 to 4, indicating that the VCO and VOO acted additively against the microbiota. Meanwhile, the oil mixture at MIC (50% for S. sanguinis and L. casei; 100% for S. mutans and mixture species) exhibited antiadherence and antibiofilm activity toward the microbiota in mixture species. CONCLUSION: The oil mixture possesses antibacterial, antibiofilm, and antiadherence properties toward the tested microbiota, mainly at 50-100% concentration of oil mixture. There was no synergistic interaction found between VCO and VOO. CLINICAL SIGNIFICANCE: Children and individuals with special care may benefit from using the oil mixture, primarily to regulate the biofilm formation and colonization of the bacteria. Furthermore, the oil mixture is natural and nontoxic compared to chemical-based oral healthcare products. How to cite this article: Ng YM, Sockalingam SNMP, Shafiei Z, et al. Biological Activities of Virgin Coconut and Virgin Olive Oil Mixture against Oral Primary Colonizers: An In Vitro Study. J Contemp Dent Pract 2024;25(3):260-266.