Propolis in the control of bacterial bovine mastitis: a tool for the production of organic milk

Bovine mastitis is one of the main causes of economic damage in dairy farms. Therefore, the control and prevention of microorganisms involved in this disease, mainly Escherichia coli, Staphylococcus aureus, and Streptococcus agalactiae, are essential. One of the most important steps for the prevention of the disease is the use of antiseptic products before and after the milking process to avoid bacteria from infecting the udder of the animal. Currently, the most used antiseptic product in dairy farms is iodine-based, and organic dairy farms, which follow several strict regulations, including the use of natural products whenever possible, are often forced to adopt non-natural antiseptic products, such as iodine-based ones, because of the lack of natural alternatives. Propolis, a natural substance produced by honeybees, has been extensively studied for its various properties, one of which is antimicrobial activity. Therefore, a new natural antiseptic product containing 1% propolis in 10% hydroalcoholic solution for the pre-dipping, and 10% glycerol solution added with 0.2% citronella oil for the post-dipping was analyzed for its capacity to reduce bacteria in vivo in order to prevent bovine mastitis, allowing its use on organic dairy farms. A total of 128 samples were analyzed in terms of bacterial growth for Enterobacteriaceae and Staphylococcus spp. using the spreadplate technique. The reduction in the bacterial concentration after the application of the products was compared between two antiseptic solutions, an iodine-based solution as the control and a propolis-based one as the natural alternative. The results obtained show a similar efficiency for both products in terms of total bacterial reduction, indicating considerable antimicrobial activity against bacteria most commonly associated with bovine mastitis. Molecular analysis was carried out for the identification of Streptococcus agalactiae; the PCR results were negative for the presence of S. agalactiae in all samples, indicating that the animals most likely did not have any form of the disease. The efficiency of the natural antiseptic was satisfactory, indicating an important find facilitating organic milk production worldwide, showcasing a natural antiseptic solution with efficient antimicrobial activity.

Gentamicin-Montmorillonite Intercalation Compounds as an Active Component of Hydroxypropylmethylcellulose Bionanocomposite Films with Antimicrobial Properties

The present study introduces an overview of gentamicin-clay mineral systems for applications in biomedicine and then focuses on the development of a series of gentamicin/clay hybrid materials to be used as the bioactive phase of hydroxypropylmethylcellulose (HPMC) to produce bionanocomposite membranes possessing antimicrobial activity of interest in wound-dressing applications. Gentamicin (Gt) was adsorbed from aqueous solutions into a montmorillonite (Cloisite®-Na+) to produce intercalation compounds with tunable content of the antibiotic. The hybrids were characterized by CHN chemical analysis, energy-dispersive X-ray analysis, X-ray diffraction, Fourier-transform infrared spectroscopy, and thermogravimetric analysis, confirming the intercalation of Gt by an ion-exchange mechanism. The release of Gt from the hybrids was tested in water and in buffer solution to check their stability. Hybrids with various amounts of Gt were incorporated into a HPMC matrix at various loadings and processed as films by the casting method. The resulting Gt-clay/HPMC bionanocomposites were characterized by means of field-emission scanning electron microscopy, and were also evaluated for their water-adsorption and mechanical properties to confirm their suitability for wound-dressing applications. The antimicrobial activity of the bionanocomposite films was tested in vitro toward various microorganisms (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium, Acinetobacter baumannii, and Klebsiella pneumonia), showing a complete bacterial reduction even in films with small Gt contents.

Silver-calcium-borates as better replacement for conventional organic antimicrobials in cosmetic products

Microbes generally develop resistance towards organic antibacterial agents like ampicillin, Sulfonamides, methicillin, etc., and progressively new drugs are being invented to replace them. Hence, replacement of organic antibacterial agents with inorganic analogues requires constant research and the present investigation reports alternatives for conventional antimicrobial agents like methylparaben, diazolidinyl urea, etc., in the cosmetic products with silver incorporated calcium borates. The chemically synthesized silver-calcium borates have been analyzed for phase purity using powder XRD analysis, nature of bonding using FTIR vibrations, and morphology using SEM. The antibacterial and antifungal studies were carried out for the novel inorganic silver-calcium borates incorporated cosmetic products. The products were also subjected to thermal & photostability studies and found to be comparable with that of commercially available products. A minimum quantity of 3 ppm of silver-calcium borate concentration was required to bring about nearly 100% bacterial reduction in the cosmetic products.

Synthesis and Characterization of Antibacterial Viscose Nonwoven Fabric by the Cooperative Action of Se Nanoparticles and Amino Hyperbranched Polymer

This research provides a new method for preparing nanoparticle-coated cellulose fabrics, which has broad application prospects in the functional fiber industry. In this work amino-terminated hyperbranched poly (HBP)-capped Selenium nanoparticles (Se NPs) were synthesized for coating viscose nonwoven fabric (VNF) via impregnation method to produce a controllable and uniform Se NPs coating on the viscose fiber surface. The prepared Se NPs and the treated VNF were characterized by the transmission electron microscope (TEM), x-ray diraction (XRD), x-ray photoelectron spectroscopy (XPS), field emission scanning electron microcopy (FE-SEM), and antibacterial measurement. The results indicate that the Se NPs were spherical shaped with an average size of 10 nm. FESEM, XRD, and XPS characterizations demonstrated that Se NPs can adsorbed and distributed uniformly on the fiber surface. Se NPs-coated VNF showed above 99.9% bacterial reduction of Staphylococcus aureus and Escherichia coli while the Se element content on VNF was about 292 mg/kg.

Dental-Plaque Decontamination around Dental Brackets Using Antimicrobial Photodynamic Therapy: An In Vitro Study

Background: In orthodontic therapy, the enamel around brackets is very susceptible to bacterial-plaque retention, which represents a risk factor for dental tissues. The aim of this study was to evaluate the effect of methylene blue and a chlorophyllin–phycocyanin mixture, used with and without light activation, in contrast with a 2% chlorhexidine solution, on Streptococcus mutans colonies. Methods: Twenty caries-free human extracted teeth were randomized into five groups. A Streptococcus mutans suspension was inoculated on teeth in groups B, C, D, and E (A was the positive-control group). Bacterial colonies from groups C, D, and E (B was the negative-control group) were subjected to photosensitizers and 2% chlorhexidine solution. For groups C and D, a combined therapy consisting of photosensitizer and light activation was performed. The Streptococcus mutans colonies were counted, and smears were examined with an optical microscope. Two methods of statistical analysis, unidirectional analysis of variance and the Tukey–Kramer test, were used to evaluate the results. Results: A statistically significant reduction in bacterial colonies was detected after the combined therapy was applied for groups C and D, but the most marked bacterial reduction was observed for group D, where a laser-activated chlorophyll–phycocyanin mixture was used. Conclusions: Photodynamic therapy in combination with methylene blue or chlorophyllin–phycocyanin mixture sensitizers induces a statistically significant decrease in the number of bacterial colonies.

Annealing Temperature Influences the Cytocompatibility, Bactericidal and Bioactive Properties of Green Synthesised TiO2 Nanocomposites from Calotropis Gigantea

Annealing is a crucial functional parameter relevant to the green synthesis and bactericidal properties of TiO2 nanocomposites (TiO2-NPs). In this work, the effect of the annealing temperature on the physicochemical and bactericidal properties of TiO2-NPs obtained from Calotropis gigantea was comprehensively studied. The synthesised TiO2-NPs were characterised using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, UV–Vis spectrophotometer and FTIR spectroscopy. The bactericidal properties were determined via the minimum inhibitory concentration (MIC) and Kirby–Bauer disc diffusion methods. The cytocompatibility of green TiO2 was further investigated using fibroblast cells lines model. Results indicated that amorphous-phase TiO2-NPs were transformed into the anatase phase at 500 °C with a crystallite size of 40.9 nm and MIC of 100 mg/mL towards S. aureus (colony count reduction from 4.3 log10 to 1.01 log10). Whereas TiO2-NPs annealed at 400 °C demonstrated no bacterial reduction, TiO2-NPs annealed at 500 °C showed a moderate zone of inhibition of 6.33–6.83 mm towards Escherichia coli and Pseudomonas aeruginosa. Findings from this study found that TiO-500C nanocomposites concentration at 100 mg/mL is cytocompatible to the fibroblast cells lines with proliferation rate/activity higher than 116% after 24 h treatment. The plant-mediated nano-sized cubic and spherical anatase TiO2-NPs encapsulated bioactive green elements, such as carbon, sodium, magnesium, chlorine, potassium, calcium and sulphur, from the C. gigantea extract, ultimately leading to versatile and eco-friendly bactericidal agents with wound-healing properties. Further studies are necessary to support the findings of this work.

Biofunctionalization of Cork with Moringa oleifera Seeds and Use of PMA Staining and qPCR to Detect Viability of Escherichia coli

Cork matrices biofunctionalized with Moringa oleifera seed extracts (MoSe) have potential for use as a biofilter with antibacterial properties to reduce waterborne pathogens. The aim of this study was to evaluate the effect of cork biofunctionalized with active antimicrobial compounds of MoSe (f-cork) on the inhibition of Escherichia coli (InhEc). The LacZ gene from a strain of E. coli was used as the target sequence using viability quantification Polymerase Chain Reaction (qPCR) and differentiation of viable and dead bacteria through selective cell viability PMA staining. To perform this, a 27−4 fractional factorial design and a biofiltration system were used to evaluate the effect of the active protein in MoSe immobilized in granulated cork on InhEc. We found that the potential for antimicrobial activity increased with f-cork for an effective maximal bacterial reduction (99.99%; p < 0.05). The effect of f-cork functionalized with MoSe on E. coli viability was of 0.024% and 0.005% for the cells exposed to PMA, respectively, being the relevant conditions in treatment 2: (0 L/min) without aeration, (5%) MoSe and (5 mm) cork particle. In conclusion, the f-cork functionalized with MoSe presented biosorbent and antibacterial properties that effectively reduced the E. coli growth.

Adding Two Antimicrobial Glasses to an Endodontic Sealer to Prevent Bacterial Root Canal Reinfection: An In Vivo Pilot Study in Dogs

Current endodontic procedures continue to be unsuccessful for completely removing pathogens present inside the root canal system, which can lead to recurrent infections. In this study, we aimed to assess the antimicrobial capacity and tissue response of two inorganic bactericidal additives incorporated into a paste root canal sealer on contaminated root dentin in vivo. An experimental study was performed in 30 teeth of five Beagle dogs. After inducing microbiological contamination, root canal systems were treated by randomly incorporating one of two antimicrobial additives into a commercial epoxy-amine resin sealer (AH Plus), i.e., G3T glass-ceramic (n = 10) and ZnO-enriched glass (n = 10); 10 samples were randomized as a control group. After having sacrificed the animals, microbiological, radiological, and histological analyses were performed, which were complemented with an in vitro bactericidal test and characterization by field emission scanning electron microscopy. The tested groups demonstrated a non-significant microbiological reduction in the postmortem periapical index values between the control group and the bactericidal glass-ceramic group (p = 0.885), and between the control group and the ZnO-enriched glass group (p = 0.169). The histological results showed low values of inflammatory infiltrate, and a healing pattern characterized by fibrosis in 44.4% of the G3T glass-ceramic and 60.0% of ZnO-enriched glass. Bactericidal glassy additives incorporated in this root canal sealer are safe and effective in bacterial reduction.

Gepotidacin Pharmacokinetics-Pharmacodynamics Against Escherichia coli in the One-Compartment and Hollow-Fiber In Vitro Infection Model Systems

Gepotidacin is a novel, first-in-class triazaacenaphthylene antibiotic that inhibits bacterial DNA replication by a distinct mechanism of action with an in vitro spectrum of activity that includes Escherichia coli . Our objectives herein were the following: 1) to identify the pharmacokinetic-pharmacodynamics (PK-PD) index associated with efficacy for gepotidacin against E. coli ; 2) to determine the magnitude of the above-described PK-PD index associated with various bacterial reduction endpoints for E. coli ; and 3) to characterize the relationship between gepotidacin exposure and on-therapy E. coli resistance amplification. A 24-hour one-compartment in vitro infection model was used to investigate the first two study objectives and a 10-day hollow-fiber in vitro infection model was used to evaluate the third objective. For the dose-fractionation studies (objective 1), in which E. coli NCTC 13441 (gepotidacin MIC, 2 mg/L) was evaluated, free-drug gepotidacin area under the concentration-time curve (AUC) from 0 to 24 h to the MIC (AUC/MIC ratio) was identified as PK-PD index most closely associated with change in bacterial burden ( R 2 = 0.925). For the dose-ranging studies (objective 2), in which four E. coli isolates (gepotidacin MIC range, 1 to 4 mg/L) were studied, the magnitude of the median free-drug gepotidacin AUC/MIC ratio associated with net bacterial stasis and 1- and 2-log 10 CFU reductions for the pooled dataset was 33.9, 43.7, and 60.7, respectively. For the hollow-fiber in vitro infection model studies (objective 3), in which one isolate ( E. coli NCTC 13441 gepotidacin MIC, 2 mg/L) was evaluated, free-drug gepotidacin AUC/MIC ratios 275 and greater were sufficient to suppress on-therapy resistance amplification. Together, the data generated from these studies will be useful to support discrimination among candidate dosing regimens for future clinical study.

Evaluation of Bacterial Reduction after Root Canal Shaping Using ProTaper Gold and WaveOne Gold Rotary Systems

Introduction The present study evaluated bacterial reduction promoted by the WaveOne system (Dentsply Maillefer, Ballaigues, Switzerland) and ProTaper Gold system (PTG; Dentsply Maillefer) in human extracted central incisors. Methods Sixty-two maxillary central incisors that were infected with Enterococcus faecalis (ATCC 51299) were sterilized with ethylene oxide for 21 days, and then root canal initial bacterial sample was collected with paper points and plated on M-Enterococcus agar. The specimens were randomly divided into two groups according to instrumentation: WaveOne Gold group (n = 30) and PTG group (n = 30). Each group was further subdivided into subgroup A (n = 15) where no activation of the irrigant was performed, and subgroup B (n = 15) where passive ultrasonic activation (PUI) was applied. The other two specimens without contamination were control asepsis. After instrumentation, samples were collected with the use of paper points. The bacterial reduction was calculated using colony-forming unit and quantitative real-time polymerase chain reaction. Data were collected and statistically analyzed. Results All techniques significantly reduced the number of bacteria in the root canal (p < 0.05), in which PTG showed superior bacterial reduction than WaveOne Gold (p > 0.05). The aseptic control group did not show any bacterial growth. PUI showed a significant bacterial reduction with the WaveOne Gold group. Conclusion It can be concluded that the single-file system, WaveOne Gold with the aid of passive ultrasonic irrigation, significantly reduce the bacterial number in the root canal similar to the multifile system, PTG.