RESUMEN

Infectious diseases have risen dramatically as a result of the resistance of many common antibiotics. Nanotechnology provides a new avenue of investigation for the development of antimicrobial agents that effectively combat infection. The combined effects of metal-based nanoparticles (NPs) are known to have intense antibacterial activities. However, a comprehensive analysis of some NPs regarding these activities is still unavailable. This study uses the aqueous chemical growth method to synthesize Co3O4, CuO, NiO and ZnO NPs. The prepared materials were characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction techniques. The antibacterial activities of NPs were tested against Gram-positive and Gram-negative bacteria using the microdilution method, such as the minimum inhibitory concentration (MIC) method. The best MIC value among all the metal oxide NPs was 0.63 against Staphylococcus epidermidis ATCC12228 through ZnO NPs. The other metal oxide NPs also showed satisfactory MIC values against different test bacteria. In addition, the biofilm inhibition and antiquorum sensing activities of NPs were also examined. The present study presents a novel approach for the relative analysis of metal-based NPs in antimicrobial studies, demonstrating their potential for bacteria removal from water and wastewater.

Asunto(s)

RESUMEN

This study investigates the effects of the antiperspirant aluminum chlorohydrate on the development of antibiotic resistance in commensal Staphylococcus epidermidis isolates. The isolates were exposed to aluminum chlorohydrate for 30 days. The bacteria that developed resistance to oxacillin and ciprofloxacin were isolated, and the expression levels of some antibiotic resistance genes were determined using quantitative reverse transcriptase PCR. Before and after exposure, the minimum inhibitory concentration (MIC) values of the bacteria were determined using the microdilution method. A time-dependent increase was observed in the number of bacteria that developed resistance and increased MIC values. Consistent with the ciprofloxacin resistance observed after exposure, an increase in norA, norB/C, gyrA, gyrB, parC, and parE gene expression was observed. In addition to aluminum chlorohydrate exposure, oxacillin resistance was observed in all test bacteria in the group only subcultured in the medium, suggesting that phenotypic resistance cannot be correlated with chemical exposure in light of these data. The increase in mecA gene expression in selected test bacteria that acquired resistance to oxacillin after exposure compared with control groups suggests that the observed resistance may have been related to aluminum chlorohydrate exposure. To our knowledge, this is the first time in the literature that the effects of aluminum chlorohydrate as an antiperspirant on the development of antibiotic resistance in Staphylococcus epidermidis have been reported.

RESUMEN

Some novel benzimidazole derivatives were synthesized and their antimicrobial activities were evaluated. Compounds 3a and 3b exhibited excellent antibacterial activity with MIC values <4 µg/mL against Staphylococcus aureus ATCC 29213 (MSSA) and Staphylococcus aureus ATCC 43300 (MRSA). Molecular docking analyzes of compounds with MIC values of 16 µg/mL and below against gram-positive bacteria and fungi were performed using FabH (ß-ketoacyl-acyl carrier protein synthase III) as bacterial protein and CYP51 (sterol 14α-demethylase) as the fungal target protein. According to the molecular docking analysis, it was calculated that sufficient protein-ligand interaction energy was liberated between the compounds 2f, 3a, 3b, 3e and 3h and the antibacterial target protein FabH and strong interactions were formed between 2f and 3h and the antifungal target protein. According to RMSD, RMSF and MMPBSA measurements obtained from molecular dynamics, it is understood that compounds 3a and 3b maintain protein-ligand stability in silico physiological conditions.

Asunto(s)

RESUMEN

This study investigates the effects of antidepressants fluoxetine, sertraline, and amitriptyline on the development of antibiotic resistance in clinical Acinetobacter baumannii isolates. The isolates were exposed to fluoxetine, sertraline, and amitriptyline for 30 days, respectively. The bacteria that developed resistance to gentamicin, imipenem, colistin, and ciprofloxacin were isolated and expression levels of some antibiotic-resistance genes were determined by quantitative reverse-transcriptase PCR. Before and after the exposure, minimum inhibitory concentration (MIC) values of the bacteria were determined by the microdilution method. The statistical analysis was performed using Student's t test. A time-dependent increase was observed in the number of bacteria that developed resistance and increased the MIC value. After exposure to fluoxetine and sertraline, decreases were observed for efflux and outer membrane porin genes in isolates that developed colistin resistance, and increases were observed in isolates that developed ciprofloxacin resistance. These observations suggest that these antidepressants have similar effects on the development of resistance. While the exposure to fluoxetine did not result in the development of resistance to imipenem, it was observed after exposure to sertraline and amitriptyline, and a common decrease in ompA gene expression was determined in these isolates. To our knowledge, the comparative effects of selected antidepressants on the development of antibiotic resistance in A. baumannii are reported and presented in the literature here for the first time.

Asunto(s)

RESUMEN

Abstract The aim of this study was to determine antimicrobial activities of Alchemilla mollis, Alchemilla persica as well as ellagic acid and miquelianin against Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans by using microbroth dilution method and anti-inflammatory activity by using human red blood cell (HRBC) membrane stabilization method. Microbroth dilution method was used to determine the antimicrobial activities. Extracts possessed activity having MIC values of 2.5-5-10mg/ mL, compounds possessed activity having MIC values of 1.25-2.5-4-5mg/mL. A.mollis aerial parts displayed the highest anti-inflammatory activity (IC50=1.22±0.07mg/mL). Ellagic acid and miquelianin were also determined as anti-inflammatory agents with 0.57±0.01mg/mL and 1.23±0.02mg/mL IC50 values, respectively. Total phenolic content and tannin content of the A.mollis and A.persica were determined as 357.00±75.80mg, 282.50±28.70mg PGE/g plant material and 18.02%, 18.63% respectively according to the method described by European Pharmacopoeia. Ellagic acid, miquelianin and catechin were analyzed by HPLC. The highest catechin content was detected in A.persica roots (6.69±0.05g/100g plant material). A.mollis aerial parts contain higher miquelianin (0.39±0.02g/plant material) and ellagic acid (1.56±0.01g/ plant material) than A.persica.

Asunto(s)

RESUMEN

OBJECTIVES: Resistance to antibiotics is recognized as one of the biggest threats to human health worldwide. Frequent and unnecessary use of antibiotics has caused infectious agents to adapt to antibiotics and thus drugs have become less effective. The resistance to many antibiotics necessitates the discovery of new antibiotics. In this study, two new and 23 previously reported 2-pyrazoline derivatives and one hydrazone derivative were evaluated for their in vitro antibacterial and antifungal activities. MATERIALS AND METHODS: For the determination of the minimum inhibitory concentration (MIC) values of compounds, microbroth dilution was used. RESULTS: The antimicrobial activities of the compounds were found in a wide range with MIC values of 32-512 µg/mL. CONCLUSION: The synthesized compounds showed moderate antimicrobial activity compared with the standards. They can be used as lead molecules for the synthesis of more effective compounds.

RESUMEN

PURPOSE: The aims to evaluate the antibacterial effect of different bioactive component containing dental adhesives before and after artificial aging. MATERIALS AND METHODS: Two bio-active adhesives; Clearfil Protect Bond and FL Bond II, two non-bioactive adhesives, Clearfil SE Bond and Clearfil S3 Bond were used for this study. Antibacterial activities of the fresh and aged samples against Streptococcus mutans were investigated with Direct Contact Test. Data were analyzed with Kruskal Wallis and Mann Whitney U multiple comparison tests. RESULTS: For fresh samples FL Bond II and Clearfil Protect Bond exhibit similar antibacterial effect but Clearfil Protect Bond showed significantly higher antibacterial effect after aging the samples (p<0.05). CONCLUSION: The incorporation of bio-active antibacterial components into adhesive systems may be considered as a fundamental component in inhibiting residual Streptococcus mutans when considering the antibacterial effect of fresh samples of bio-active adhesives.

RESUMEN

For many years, plants are used for treatment of various diseases. In general, plants have rather more therapeutic benefits and fewer adverse effects compared with the synthetic drugs. The purpose of this study was to determine the in vitro antimicrobial potentials of fifteen plant species from Anatolia region of Turkey against some selected bacteria and a yeast strain. The extracts from belong to nine families were examined against Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 43300 (MRSA), Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922 and Candida albicans ATCC 10231 using disc diffusion and micro dilution methods. According to the obtained results, all plant extracts showed different ranges of antibacterial activity against S. aureus ATCC 43300 and S. aureus ATCC 25923 strains. Flower and leaves extracts of R. lutea, leaves extract of E. ritro, flower and leaves extracts of H. europaeum, leaves extract of E. macroclada, fruit and leaves extracts of Z. fabago, flower extract of C.crupinastrum, leaves extract of D. tenuifolia showed different ranges of antifungal activity against C. albicans.

Asunto(s)

RESUMEN

OBJECTIVES: The present study aimed to evaluate the antimicrobial and anti-inflammatory activities of methanol extracts and n-hexane, ethyl acetate, chloroform, and water fractions of five Lathyrus species, namely Lathyrus armenus, Lathyrus aureus, Lathyrus cilicicus, Lathyrus laxiflorus subsp. laxiflorus, and Lathyrus pratensis, growing in Turkey. MATERIALS AND METHODS: The antimicrobial activities were screened against Staphylococcus aureus ATCC 29213, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. Broth dilution was used to determine the antimicrobial activities of extracts and fractions. In vitro anti-inflammatory activity of these extracts and fractions was determined using human red blood cell membrane stabilization. RESULTS: The results demonstrated that ethyl acetate fractions of the tested species exhibited higher antimicrobial activity than the other extracts. Among all of the tested extracts and fractions, the highest anti-inflammatory activity was detected in water fractions. Furthermore, water fractions of L. pratensis showed better anti-inflammatory activity than acetylsalicylic acid and diclofenac sodium, which were used as standard drugs in this assay. CONCLUSION: The results indicate the membrane stabilizing effect of the various extracts and fractions of the Lathyrus species and could constitute preliminary work for in vivo anti-inflammatory activity experiments.

RESUMEN

In this study, ciprofloxacin hydrochloride (CIP)-loaded poly-ε-caprolactone (PCL) nanoparticles were prepared for pulmonary administration. CIP-loaded PCL nanoparticles were prepared using solid-in-oil-in-water (s/o/w) emulsion solvent evaporation method, and the effects of various formulation parameters on the physicochemical properties of the nanoparticles were investigated. PCL nanoparticles showed spherical shapes with particle sizes around 143-489 nm. Encapsulation efficiency was found to be very low because of water-solubility properties of CIP. However, the surface modification of nanoparticles with chitosan caused an increase in the encapsulation efficiency of nanoparticles. At drug release study, CIP-loaded PCL nanoparticles showed initial burst effect for 4 h and then continuously released for 72 h. Nanocomposite microparticles containing CIP-loaded PCL nanoparticles were prepared freeze-drying method and mannitol was used as carrier material. Tapped density and MMADt results show that nanocomposite microparticles have suitable aerodynamic properties for pulmonary administration. Antimicrobial efficacy investigations showed that CIP-encapsulated PCL nanoparticles and nanocomposite microparticles inhibited the growth of bacteria. Also, when the antimicrobial activity of the nanoparticles at the beginning and at the sixth month was examined, it was found that the structure of the particulate system was still preserved. These results indicated that nanocomposite microparticles containing CIP-loaded PCL nanoparticles can be used for pulmonary delivery.

Asunto(s)

RESUMEN

BACKGROUND: The genus Lactobacillus has recently been the focal point of researchers due to their ability to produce secondary metabolites with antimicrobial effects. OBJECTIVE: The aim of this study was to identify vaginal Lactobacillus sp. by analyzing 16S rRNA gene sequence, to investigate into antimicrobial activities of secondary metabolites produced by these isolates and to determine the quantities of lactic acid, acetic acid and hydrogen peroxide in secondary metabolites using High-Performance Liquid Chromatography. METHODS: Antimicrobial activities of secondary metabolites were investigated against test microorganisms using Agar Well Diffusion and Agar Spot Methods. RESULTS: According to the results, 18 L. crispatus, 17 L. gasseri, 5 L. jensenii, 4 L. vaginalis, 3 L. fermentum, 2 L. coleohominis, 1 L. saerimneri, 1 L. reuteri, 1 L. johnsonii and 1 L. helveticus were identified. Isolates were frequently found to be effective against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae RSKK 578 and Bacillus subtilis ATCC 6633. None of the isolates showed activity against Staphylococcus aureus ATCC 43300, S. epidermidis ATCC 12228, S. epidermidis ATCC 35984 and Candida albicans ATCC 10231. Secondary metabolites of all tested isolates contain hydrogen peroxide between 7.306 and 0.33 µg/µL range. CONCLUSION: It was found that the secondary metabolites of some isolates contained both acetic and lactic acid, while some of them contained either acetic or lactic acid.

Asunto(s)

RESUMEN

Nosocomial infections which exhibit an increasing trend worldwide, are important contributors to morbidity and mortality. Most bacteria that cause nosocomial infections can retain their viability even after exposure to disinfectants in routine practice. This study was conducted to determine the susceptibilities of nosocomial Staphylococcus aureus and Enterococcus spp. isolates to various disinfectants. A total of 30 S.aureus [16 were methicillin-resistant (MRSA), 14 were methicillin-susceptible (MSSA)] and 21 Enterococcus spp. (13 E.faecalis, 7 E.faecium, 1 non-typable Enterococcus spp.) strains isolated from clinical samples of hospitalized patients as nosocomial infection agents in the Central Microbiology Laboratory of Ibn-i Sina Hospital, Ankara University, Faculty of Medicine, were included in the study. Glutaraldehyde (2% wt/vol), chlorhexidine gluconate (4% wt/vol), 2-propanol (70% vol/vol), povidone iodine (7.5% wt/vol), povidone iodine (10% wt/vol) and hydrogen peroxide (3% wt/vol) susceptibilities of the isolates were investigated by quantitative suspension test at contact times of 3, 5, and 10 minutes. All of the isolates were found susceptible to glutaraldehyde (2%), chlorhexidine gluconate (4%), povidone iodine (7.5%), povidone iodine (10%) and 2-propanol (70%) at all tested contact times. However, 12 S.aureus (5 MSSA, 7 MRSA) and 3 enterococci (2 E.faecium, 1 E.faecalis) isolates were found susceptible to hydrogen peroxide (3%) at 3 minutes contact time; 11 S.aureus (4 MSSA, 7 MRSA) and 7 E.faecalis isolates were found susceptible at 5 minutes contact time, and 6 S.aureus (4 MSSA, 2 MRSA) and 3 enterococci (1 E.faecium, 2 E.faecalis) isolates were found susceptible at 10 minutes contact time. One MSSA and 8 enterococci (4 E.faecium, 3 E.faecalis, 1 Enterococcus spp.) isolates were found resistant to hydrogen peroxide (3%) at 10 minutes contact time. In conclusion, glutaraldehyde (2%), chlorhexidine gluconate (4%), povidone iodine (7.5%), povidone iodine (10%) and 2-propanol (70%) can be safely used against S.aureus and Enterococcus spp. owing to their high effectiveness, however, hydrogen peroxide (3%) should not be preferred against those strains due to the presence of resistant isolates, in Ankara University Ibn-i Sina Hospital.

Asunto(s)