Determination of biological activities of nanoparticles containing silver and copper in water disinfection with/without ultrasound technique.

The final and most crucial step in obtaining clean water is disinfection. More innovative methods of water disinfection have recently been sought. Water disinfection is a promising application for nanoparticles as disinfectants. As a contribution to the literature, biofilm and metal-containing nanoparticles as antiadhesion inhibitors were used in conjunction with ultrasound in this study. The microbroth dilution test was used to reveal the microbiological antibacterial activities of different concentrations of AgNO3 and CuCl2 containing nanoparticles against the Escherichia coli ATCC 25,922 strain, which is an indicator bacterium in water systems. Antibiofilm activities were then investigated using biofilm attachment and biofilm inhibition tests. The inhibitory effect of nanoparticle ultrasonic waves on biofilm contamination was determined using a novel approach. Human keratinocyte cells (HaCaT cell line) were used in cell culture studies after water disinfection, and their cytotoxic effects were demonstrated using the MTT assay. The findings suggest that the nanoparticles utilized might be a viable choice for water disinfection applications. Furthermore, employing ultrasound at low doses with nanoparticles resulted in greater results. One feasible option is to employ nanoparticles to cleanse water without producing cytotoxicity.

Biofilm formation of Candida Spp. isolated from the vagina and antibiofilm activities of lactic acid bacteria on the these Candida Isolates.

BACKGROUND: In this study, it was aimed to investigate the effects of bacterial cells and cell-free filtrates of Lactobacillus acidophilus 8MR7 and Lactobacillus paracasei subspecies paracasei 10MR8 on the biofilm formation of 3 Candida tropicalis, 3 C. glabrata and 12 C. albicans isolated from the vagina and identified their virulence factors. METHODS: Haemolytic activities esterase activities, and phospholipase activities as virulence factors of Candida strains were determined. Biofilm formations of these isolates were determined by Congo Red agar and microtitration plate method. Antibiofilm activities of bacterial cells and cell-free filtrates of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 on Candida isolates were determined by the microtitration plate method. RESULT: Bacterial cells of L. acidophilus 8MR7 and L. paracasei subspecies paracasei 10MR8 were not very effective in the inhibition of biofilm, whereas it has been observed that the cell-free filtrates of these bacteria inhibit the formation of biofilms of Candida strains. Although the main mechanism for inhibiting the formation of Candida spp. biofilm is the competition for adhesion, it is concluded that the substances contained in the cell-free filtrates of lactic acid bacteria are also important. CONCLUSION: These isolates promise hope as potential bacteria that can be used for anti-adhesion purposes in health-care materials.

Anticandidal activities of lactic acid bacteria isolated from the vagina

Background/aim: Lactic acid bacteria prevent the overgrowth of pathogenic agents and opportunistic pathogens in the vagina. Moreover, lactic acid bacteria contribute to the preservation of vaginal microbiota by producing antimicrobial agents. Previous studies showed that some lactic acid bacteria exhibited antimicrobial activity against Candida species causing yeast vaginosis as well as many bacterial pathogens. Materials and methods: The antifungal activities of various lactic acid bacteria isolated from the vagina of healthy women on some Candida species isolated from the vagina were investigated by agar diffusion technique. Results: Most of the lactic acid bacteria that belong to the species of Lactobacillus crispatus, L. fermentum, L. acidophilus, L. paracesei subsp. paracesei, L. pentosus, and L. plantarum exhibited antifungal activity in varying ratios against C. albicans, C. glabrata, and C. tropicalis strains isolated from the vagina. Conclusion: The lactic acid bacteria are useful microorganisms associated with a variety of probiotic properties. In this sense, our lactic acid bacteria isolates with high antifungal activity may be promising candidates as probiotic microorganisms in the inhibition of vaginal candidiasis, which is one of the most prevalent problems, or in the protection against candidiasis. We will continue our studies in this area.

Design and characterization of nanocarriers loaded with Levofloxacin for enhanced antimicrobial activity; physicochemical properties, in vitro release and oral acute toxicity

Inorganic and carbon based nanomaterials are widely used against several diseases, such as cancer, autoimmune diseases as well as fungi and bacteria colonization. In this work, Santa Barbara Amorphous mesoporous silica (SBA), Halloysite Nanotubes (HNTs) and Multiwalled Carbon Nanotubes (CNTs) were loaded with fluoroquinolone Levofloxacin (LVF) to be applied as antimicrobial agents. The prepared via adsorption nanocarriers were characterized by Fourier-Transformed Spectroscopy, Scanning Electron Microscopy as well as High Pressure liquid Chromatography. In vitro release studies were carried out using Simulated Body Fluid at 37oC and data analyzed by various kinetic models showing slow dissolution over 12-24 hours. Antimicrobial studies showed improved antibacterial activity against Escherichia coli, Enterococcus faecalis, Listeria monocytogenes, Staphylococcus aureus, and Staphylococcus epidermidis compared to neat nanomaterials. CNTs were found to be the most promising candidates for LVF delivery and they were chosen to be further studied for their acute oral toxicity and histopathological examination using C57/Black mice. Histological examination depicted that drug loading did not affect mice organs morphology as well as hepatocyte degeneration, central vein degeneration and parenchymal necrosis scores. To conclude, the prepared nanomaterials present significant characteristics and can act as antimicrobial drug carriers; CNTs found to be safe candidates when orally fed to mice.

Identifying probiotic characteristics of Lactobacillus crispatus isolated from the vagina

Lactobacilli prevent overproduction of pathogenic microorganisms and contribute protecting vaginal microbiota. Many probiotic microorganisms are categorized as Lactic Acid Bacteria. In this study, it was aimed identifying probiotic characteristics of Lactobacillus crispatus isolated from the vagina of a healthy woman. For this purpose, lactic acid, hydrogen peroxide and proteolytic activity quantities and auto-aggregation, co-aggregation and hydrophobicity abilities of Lactobacillus crispatus, which has been isolated and identified by 16s rRNA sequence analysis, were determined. Additionally, bile salt and acid resistance, along with antibiotic susceptibility of Lactobacillus crispatus were analyzed by the end of 3 hours. Lactic acid, hydrogen peroxide and proteolytic activity quantities of Lactobacillus crispatus were measured 2.275%, 0.334±0.075 µg/mL and 2.131±0,000 mg/mL respectively. The findings include existence of co-aggregation and auto-aggregation ability, but not hydrophobicity. By the end of 3 hours, the viability was preserved in 0.1% and 0.3% bile salt medium and, at pH 3. L. crispatus exhibited resistance to methicillin, metronidazole, oxacillin, and sulfamethoxazole + trimethoprim, but the bacteria exhibited susceptibility to tested the other antibiotics. This study will make an important contribution to the literature about probiotic characteristics of L. crispatus and our strain isolated from the vagina might be considered as a candidate probiotic.

Investigation of Antimicrobial Activities of Some Herbs Containing Essential Oils and Their Mouthwash Formulations.

OBJECTIVES: The aim of this study was to prepare pharmaceutical formulations of mouthwashes and to examine the antimicrobial activities of essential oils obtained from plants used traditionally in Turkey for oral infections. MATERIALS AND METHODS: Essential oils were obtained from herbal drugs using water distillation with Clevenger apparatus. The antimicrobial capacities of mouthwash formulations containing a mixture of essential oils with proportions of 4.5% and 9.0% were examined using disc diffusion and microbroth dilutions. RESULTS: The inhibition zone diameters were determined to vary between 7 and 59 mm. The static and cidal activity was generally 50% and greater than 50% when pure essential oil samples were applied on microorganism specimens. Formulation F2, which contained a mixture of essential oils with proportions of 4.5%, showed 6.25% minimum bactericidal effect on Staphylococcus aureus ATCC 25923, and 3.125% the minimum inhibitory concentration and minimum bactericidal concentration on all other microorganisms. The antimicrobial effect of pure essential oil samples applied on microorganisms was lower than of mouthwashes formulations; the antimicrobial effect of F2, which contained a mixture of essential oils with proportions of 4.5% was higher than formulation F1, which contained a mixture of essential oils with proportions of 9%. CONCLUSION: The results obtained by these methods allow us to conclude that the essential oils and the prepared F1 and F2 mouthwash formulations exerted activity against microorganisms affecting the oral cavity. The F2 formulation also had significant antimicrobial activity on the tested microorganisms.

Two Different Approaches for Oral Administration of Voriconazole Loaded Formulations: Electrospun Fibers versus ß-Cyclodextrin Complexes.

In this work, a comparison between two different preparation methods for the improvement of dissolution rate of an antifungal agent is presented. Poly(ε-caprolactone) (PCL) electrospun fibers and ß-cyclodextrin (ß-CD) complexes, which were produced via an electrospinning process and an inclusion complexation method, respectively, were addressed for the treatment of fungal infections. Voriconazole (VRCZ) drug was selected as a model drug. PCL nanofibers were characterized on the basis of morphology while phase solubility studies for ß-CDs complexes were performed. Various concentrations (5, 10, 15 and 20 wt %) of VRCZ were loaded to PCL fibers and ß-CD inclusions to study the in vitro release profile as well as in vitro antifungal activity. The results clearly indicated that all formulations showed an improved VRCZ solubility and can inhibit fungi proliferation.

Is it safe to reuse dental implant healing abutments sterilized and serviced by dealers of dental implant manufacturers? An in vitro sterility analysis.

PURPOSE: This study was undertaken to investigate the sterility of used healing abutments sterilized and serviced by dealers of dental implant manufacturers. MATERIALS AND METHODS: Sixty used but sterilized healing abutments in sealed sterilization pouches were obtained from 6 manufacturers unaware of the study design and equally grouped from A to F. The sterilization pouches were examined for perforation. The driver slots and screw grooves of healing abutments were examined for calculus and scratches under a ×5 LED magnifying lamp, without opening the pouches. Each abutment was immersed in brain heart infusion broth in test tubes and incubated. RESULTS: Macroscopic observation of 57 healing abutments revealed dirty screw grooves (10.5%) and partially filled driver slots (5.2%). None of the group C, E, and F samples showed turbidity. Penicillium variabile was morphologically identified in 3 abutments of group A. Enterococcus faecalis and E faecium were detected in 1 abutment each of groups B and D, respectively. CONCLUSION: Reuse of healing abutments can be cost effective in dental practice. However, used abutments sterilized and serviced by dental implant dealers might be a source of cross-infection. They should therefore be cleaned and resterilized before reuse as a precaution.

In vitro activities of colistin, tigecycline and tobramycin, alone or in combination, against carbapenem-resistant Enterobacteriaceae strains.

The aim of this study was to investigate the activities of various antibiotics, alone or in combination, against carbapenem-resistant Enterobacteriaceae (CRE). Minimum inhibitory concentrations (MICs) of meropenem, colistin, tigecycline and tobramycin were determined by microbroth dilution against 40 clinical strains. Carbapenemase-encoding genes were detected by PCR using specific primers. The in vitro synergistic activities of tigecycline, colistin and tobramycin in double antibiotic combinations were determined by the microbroth chequerboard technique, and results were interpreted using the fractional inhibitory concentration index (FICI). To confirm the results acquired by the chequerboard method, time-kill assays were performed on eight isolates representing four different susceptibility patterns. Based on MIC90 values, colistin was the most potent agent, followed by tigecycline and tobramycin. According to PCR studies, carbapenem resistance in tested Enterobacteriaceae isolates was most often mediated by OXA-48-type carbapenemases. With an FICI of ≤0.5 as the cut-off, synergistic interactions were most frequent with tigecycline+tobramycin (30%); other results for synergistic interactions were 23% for colistin+tobramycin and 9% for colistin+tigecycline. By time-kill assays, all tested antibiotic combinations demonstrated synergistic activity against at least three of the eight strains at 1× or 4× MIC. Overall, the combinations used in this study were effective regimens, demonstrating synergy or no interaction (indifference) against all tested strains. No antagonism was observed with either of the techniques. The findings of this study might play a useful role in selecting appropriate combinations when a single agent is inadequate against CRE strains.