ABSTRACT
BACKGROUND: COVID-19 is a public health emergency with a high mortality rate and it reduces the patient's Health-Related Quality of Life (HRQoL) significantly. This effect is measured in the current study. METHODS: In a cross-sectional study in Iran, 320 randomly selected treated patients from COVID-19 were studied. To collect the required data, we applied a questionnaire that included socio-demographic factors, clinical characteristics, and questions on the patients' HRQoL. Time trade-off (TTO) approach was used to measure the lost HRQoL attributed to COVID-19. Besides, we applied a two-limit Tobit regression model to determine the effects of the socio-demographic factors on patients' health utility and the visual analogue scale approach was used to estimate the perceived total current health status. RESULTS: The overall mean (SE) and median (IQR) of the health utility values were 0.863 (0.01) and 0.909 (0.21) respectively. These values for the traders (those who were willing to lose a part of their remaining time of life to avoid the disease) were estimated at 0.793 (0.01) and 0.848 (0.17), respectively. The lowest amount of utility value belonged to the elderly (mean (SE) = 0.742 (0.04); median (IQR) = 0.765 (0.42)) and those living in rural areas (mean (SE)) = 0.804 (0.03); median (IQR) = 0.877 (0.30)). The univariate analysis showed that age, place of residence, and household size had a statistically significant effect on health utility. Moreover, findings of the regression analysis indicated that the participants' age and hospitalization status were the key determinants of COVID-19 health utility value. CONCLUSION: COVID-19 is associated with a substantial and measurable decrease in HRQoL. This decline in HRQoL can be directly compared with that induced by systemic health states.
Subject(s)
COVID-19/psychology , Quality of Life , Adult , Aged , COVID-19/diagnosis , COVID-19/virology , Cross-Sectional Studies , Female , Health Status , Humans , Iran , Male , Middle Aged , SARS-CoV-2/isolation & purification , Surveys and QuestionnairesABSTRACT
Diabetic foot ulcer (DFU) is a serious and costly complication in diabetes which affects different aspects of life and can reduce patient's quality of life. Various views to manage DFU have been introduced. The nurse-led team, as a multidisciplinary team, can be effective due to a holistic approach to some disease management; but in patients with DFU it has not been assessed. Therefore, this study was designed to determine the effect of nurse-led care on quality of care (QOC) and improvement of HbA1C in Patients with DFU. This was a randomized clinical trial study performed on 52 patients with DFU. Patients were randomly assigned into two groups: nurse-led care intervention and standard care. The study was conducted in one of the hospitals affiliated to Tehran University of Medical Sciences. Data were collected using two questionnaires: Demographic characteristics and Quality Patient Care Scale (QUALPACS) and taking a blood sample for HbA1C. The nurse-led Care interventions were conducted in three stages: Integrated, Interdisciplinary, and Comprehensive. Descriptive and analytic statistical methods were used to analyze the data. P < .05 was considered significant. The results demonstrated that according to repeated measures test, (before, 4 and 12 weeks after the intervention), the level of QOC dimensions (Psychosocial, communication and physical aspect) in the nurse-led group had a significant difference with control group (P < .0001). Also, according to the results of Independent t test, there was a significant difference in total QOC scoring and HbA1c between intervention and control groups after the intervention and follow up (P < .0001). Considering the burden of diabetes and DFUs, it seems that the establishment of a nurse-led care approach can be an effective strategy to manage and treat these patients, and eliminate the disruption of care and achieve optimal care quality.
Subject(s)
Diabetic Foot/blood , Diabetic Foot/nursing , Glycated Hemoglobin/metabolism , Practice Patterns, Nurses' , Quality of Health Care , Aged , Female , Humans , Iran , Male , Middle Aged , Outcome Assessment, Health CareABSTRACT
The Lactococcus lactis is known as a probiotic bacterium and also as a producer of nisin. Nisin has been approved by related legal agencies to be used as an antimicrobial peptide in food preservation. In fact, the L. lactis is present in different food products along with other micro-organisms especially pathogenic bacteria. So, it is important to predict the behavior of nisin-producer strain in contact with other pathogens. In this regard, nisin gene expression and the level of secreted biologically active form of nisin by L. lactis subsp. lactis in modified MRS broth and whey solution in co-culture with Listeria monocytogenes or Salmonella enterica were studied. The nisin concentration was determined by microbiological assay method and the transcription level of nisin gene was assayed through quantitative reverse transcription PCR (RT-qPCR). According to our results, the highest concentration of nisin and its gene transcription level were detected in mono- and co-cultures after 16â¯h of incubation, concurrent with the end of L. lactis exponential phase of growth. The nisin mRNA copies in co-cultures were higher than mono-cultures only at 16â¯h of incubation. But, differences between nisin concentrations in mono- and co-cultures were significant at 16, 24â¯h and at 12, 16, 24â¯h of incubation in the modified MRS medium and whey solution, respectively. This incompatibility could be related to the low availability of components required for nisin precursor modification, transportation and processing in mono-cultures. Overall, the L. lactis produced more mature and active nisin when it was in contact with pathogenic bacteria.
Subject(s)
Anti-Bacterial Agents/metabolism , Antimicrobial Cationic Peptides/metabolism , Gene Expression Regulation, Bacterial/genetics , Lactococcus lactis/metabolism , Listeria monocytogenes/growth & development , Microbial Interactions/physiology , Nisin/metabolism , Salmonella enterica/growth & development , Coculture Techniques , Food Microbiology , Food Preservation , Lactococcus lactis/genetics , Lactococcus lactis/growth & development , Nisin/geneticsABSTRACT
A series of 7-piperazinylquinolones containing a (benzo[d]imidazol-2-yl)methyl moiety were designed and synthesized as new antibacterial agents. The antibacterial activity of title compounds was evaluated against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis and Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia) microorganisms. Among the tested compounds, the N1-cyclopropyl derivative 4a showed the highest activity against S. aureus, S. epidermidis, B. subtilis and E. coli ([Formula: see text] [Formula: see text]g/mL), being 2-4 times more potent than reference drug norfloxacin. A structure-activity relationship study demonstrated that the effect of the nitro group on the benzimidazole ring depends on the pattern of substitutions on the piperazinylquinolone.
Subject(s)
Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Piperazines/pharmacology , Quinolones/pharmacology , Anti-Bacterial Agents/chemistry , Gram-Negative Bacteria/growth & development , Gram-Positive Bacteria/growth & development , Microbial Sensitivity Tests , Molecular Docking Simulation , Piperazines/chemistry , Quinolones/chemistry , Structure-Activity RelationshipABSTRACT
A novel series of ciprofloxacin-dithiocarbamate hybrids 7a - 7l were designed, synthesized, and evaluated against Gram-positive and Gram-negative bacteria. A significant part of the title compounds showed considerable antibacterial activity against Gram-positive species. The most potent compound against Gram-positive bacteria was 2-chloro derivative 7h and the most potent derivative against Gram-negative bacteria was 3-chloro compound 7i. In vitro antibacterial evaluation of compound 7h against clinically isolated bacteria methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) showed that this compound acted better than ciprofloxacin against the latter bacteria. Docking study of compound 7h in the active site of S. aureus DNA gyrase revealed that this ciprofloxacin-dithiocarbamate derivative interacted with the main components of the active site of the enzyme.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Ciprofloxacin/analogs & derivatives , Staphylococcal Infections/drug therapy , Staphylococcus aureus/drug effects , Thiocarbamates/chemical synthesis , Thiocarbamates/pharmacology , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Catalytic Domain/drug effects , Ciprofloxacin/chemical synthesis , Ciprofloxacin/pharmacology , DNA Gyrase/chemistry , DNA Gyrase/metabolism , Humans , Methicillin-Resistant Staphylococcus aureus/chemistry , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/metabolism , Molecular Docking Simulation , Staphylococcus aureus/chemistry , Staphylococcus aureus/metabolismABSTRACT
A series of new triazole alcohol antifungals were designed by replacing one of the triazolyl moiety from fluconazole with a distinct 4-amino-3-mercapto-1,2,4-triazole motif, which is found in some antimicrobial agents. The antimicrobial susceptibility testing of target compounds demonstrated that the direct analogs of fluconazole (difluorophenethyl-triazoles) were less active against fungi, while compound 10h containing dichloro substitutions on both phenyl rings of the molecule had potent activity against yeasts including Candida albicans (four strains) and Cryptococcus neoformans (MICs = 2-8 µg/mL). Also, compound 10h was active against Candida parapsilosis, Epidermophyton floccosum, and Trichophyton mentagrophytes, while it showed no activity against Gram-positive and Gram-negative bacteria. Finally, a molecular docking study suggested that compound 10h interacts suitably with lanosterol 14α-demethylase, which is the key enzyme in ergosterol biosynthesis.
Subject(s)
Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Fluconazole/analogs & derivatives , Triazoles/chemistry , Triazoles/pharmacology , Antifungal Agents/chemical synthesis , Antifungal Agents/metabolism , Chemistry Techniques, Synthetic , Fluconazole/chemistry , Fungi/drug effects , Microbial Sensitivity Tests , Models, Molecular , Stereoisomerism , Triazoles/chemical synthesis , Triazoles/metabolismABSTRACT
CONTEXT: Ferula cupularis (Boiss.) Spalik et S. R. Downie (Apiaceae) is a common plant in Iran that grows in the foothills of Dena Mountain. In traditional folk medicine, this plant has different applications, but there are no studies proving their uses. OBJECTIVE: This study is the first attempt to investigate the chemical composition and antibacterial effect of the essential oils of F. cupularis. MATERIALS AND METHODS: The essential oils from flower, leaf, and stem of F. cupularis were analyzed by using GC and GC-MS. Antibacterial activity of essential oils was determined by microdilution method against Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. RESULTS: The essential oil from flower of F. cupularis contained 15 monoterpene, 13 oxygenated monoterpene, and 2 sesquiterpene hydrocarbons. The leaf essential oil contained 12 monoterpene, 13 oxygenated monoterpene, 2 sesquiterpene, 6 oxygenated sesquiterpene hydrocarbons, and 3 non-terpenoid components. Stem essential oil contained one monoterpene, 23 oxygenated monoterpene, 2 sesquiterpene, and 6 oxygenated sesquiterpene hydrocarbons. The MIC value of stem essential oil was 2.85 mg/mL against both Gram-positive bacteria and Gram-negative bacteria except P. aeruginosa which was inhibited at 22.75 mg/mL. The MIC values of leaf and flower essential oils were higher than 5.69 and 22.75 mg/mL, respectively. DISCUSSION: This study highlighted the strong antibacterial effect of Ferula cupularis's essential oil which might be due to its high content of oxygenated monoterpene hydrocarbons. CONCLUSION: Our results suggested that this plant may be a good candidate for further biological and pharmacological investigations.
Subject(s)
Anti-Bacterial Agents/chemistry , Ferula/chemistry , Oils, Volatile/chemistry , Plant Oils/chemistry , Terpenes/chemistry , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/pharmacology , Ferula/growth & development , Flowers/chemistry , Gas Chromatography-Mass Spectrometry , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Iran , Microbial Sensitivity Tests , Oils, Volatile/isolation & purification , Oils, Volatile/pharmacology , Plant Leaves/chemistry , Plant Oils/isolation & purification , Plant Oils/pharmacology , Plant Stems/chemistry , Terpenes/isolation & purification , Terpenes/pharmacologyABSTRACT
Ventilator-associated pneumonia (VAP) is a severe hospital-acquired infection that endangers patients' treatment in intensive care units (ICUs). One of the leading causes of VAP is biofilm formation on the endotracheal tube (ETT) during ventilation. This study reports a combination of laccase-gadolinium phosphate hybrid nanoparticles (laccase@GdPO4·HNPs) and enzyme mediator with an antibiofilm property coated on the surface of the ETT. The hybrid nanostructures were fabricated through a simple, rapid, and facile laccase immobilization method, resulting in efficiency and yield percentages of 82 ± 6% and 83 ± 5%, respectively. The surface of the ETT was then functionalized and coated with the constructed HNP/catechol. The layered ETT was able to reduce the surface adhesion of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus by 82.1%, 84.5%, and 77.1%, respectively. The prepared ETT did not affect the viability of human lung epithelial cells L929 and A549 at concentrations of 1-5 mg mL-1. The layered ETT produced a strong computed tomography (CT) signal in comparison with iobitridol. The HNP/catechol-coated ETT exhibited a Gd3+ release of 0.45 ppm over 72 h, indicating reduced risks of cytotoxicity arising from the metal ions. In this research we develop a biofilm-resistant and contrasting agent-based ETT coated with green synthesized laccase@GdPO4·HNPs.
Subject(s)
Nanoparticles , Pneumonia, Ventilator-Associated , Humans , Gadolinium , Laccase , Phosphates , Intubation, Intratracheal , Biofilms , CatecholsABSTRACT
PURPOSE OF REVIEW: Global health concerns persist in the realm of cardiovascular diseases (CVDs), necessitating innovative strategies for both prevention and treatment. This narrative review aims to explore the potential of short-chain fatty acids (SCFAs)-namely, acetate, propionate, and butyrate-as agents in the realm of postbiotics for the management of CVDs. RECENT FINDINGS: We commence our discussion by elucidating the concept of postbiotics and their pivotal significance in mitigating various aspects of cardiovascular diseases. This review centers on a comprehensive examination of diverse SCFAs and their associated receptors, notably GPR41, GPR43, and GPR109a. In addition, we delve into the intricate cellular and pharmacological mechanisms through which these receptors operate, providing insights into their specific roles in managing cardiovascular conditions such as hypertension, atherosclerosis, heart failure, and stroke. The integration of current information in our analysis highlights the potential of both SCFAs and their receptors as a promising path for innovative therapeutic approaches in the field of cardiovascular health. The idea of postbiotics arises as an optimistic and inventive method, presenting new opportunities for preventing and treating cardiovascular diseases.
Subject(s)
Cardiovascular Diseases , Fatty Acids, Volatile , Receptors, G-Protein-Coupled , Humans , Fatty Acids, Volatile/metabolism , Receptors, G-Protein-Coupled/metabolism , Gastrointestinal Microbiome/drug effects , Propionates , Animals , Butyrates , Receptors, Cell SurfaceABSTRACT
Laccase@Ni3(PO4)2 hybrid nanoflowers (HNFs) were prepared by the anisotropic growth of biomineralized nickel phosphate. The immobilization yield was 77.5 ± 3.6 %, and the immobilized enzyme retained 50 % of its initial activity after 18 reusability cycles. The immobilized and free enzymes lost 80 % of their activity after 18 and 6 h incubation in municipal wastewater effluent (MWWE), respectively. The increase in α-helix content (8 %) following immobilization led to a more rigid enzyme structure, potentially contributing to its improved stability. The removal of ciprofloxacin from MWWE by laccase@Ni3(PO4)2·HNFs/p-coumaric acid oxidation system was optimized using a Box-Behnken design. Under the optimized conditions [initial laccase activity (0.05 U mL-1), the concentration of p-coumaric acid (2.9 mM), and treatment time (4.9 h)], the biocatalyst removed 90 % of ciprofloxacin (10 mg L-1) from MWWE. The toxicity of ciprofloxacin against some G+ and G- bacteria was reduced by 35-70 %, depending on their strain. The EC50 of ciprofloxacin for the alga Raphidocelis subcapitata reduced from 3.08 to 1.07 mg L-1 (p-value <0.05) after the bioremoval. Also, the acute and chronic toxicity of identified biodegradation products was lower than ciprofloxacin at three trophic levels, as predicted by ECOSAR software.
Subject(s)
Laccase , Wastewater , Wastewater/toxicity , Laccase/chemistry , Enzymes, Immobilized/chemistry , Biodegradation, Environmental , Anti-Bacterial Agents/pharmacologyABSTRACT
Objective: Cedrus deodara (Roxb. Ex Lamb.) G. Don possesses various biological activities, which have been documented in modern and traditional medicine. In this study, burn wound healing activity of the methanol extract of C. deodara wood was evaluated via a burn wound model in Wistar rats. Methods: The methanol extract of C. deodara was evaluated for the contents of phenolic compounds, flavonoids, and tannins. Also, its antioxidant activity was determined using the DPPH assay. Then, a topical ointment containing the methanol extract of C. deodara (10%) was used to evaluate the healing effects on a model of second-degree thermal burn in 4 groups of 7 rats within 21 days. In this respect, average wound surface area, wound closure, and various histological features were examined. Results: Our findings revealed that the wounds treated with the methanol extract of C. deodara showed higher wound contraction (33.6, 87.1, and 93.4% on days 7, 14, and 21, respectively) compared with the positive control (27.6, 80.7, and 88.3% on days 7, 14, and 21, respectively) and the negative control (20.1, 77.9, and 80.2% on days 7, 14, and 21, respectively). According to the results from epitheliogenesis score, the number of inflammatory cells, neovascularization, and collagen density, good burn wound healing activity of the methanol extract of C. deodarawas demonstrated. Conclusion: Using the methanol extract of C. deodara in an ointment formulation can be developed to prevent or reduce burn injury progression.
ABSTRACT
Lactiplantibacillus plantarum cells were encapsulated in a mixture of cationic and anionic polymers, with the final composition stabilized through freeze-drying. A D-optimal design was used to examine the effects of different polymer concentrations as well as adding prebiotics on the probiotic viability and swelling behavior of the formulations. Scanning electron micrographs revealed stacked particles capable of rapidly absorbing significant amounts of water. These images corresponded to initial swelling percentages of around 2000% for the optimal formulation. The optimized formula had a viability percentage of more than 82%, with the stability studies suggesting that the powders should be stored at refrigerated temperatures. The physical characteristics of the optimized formula were examined to ensure compatibility with its application. According to antimicrobial evaluations, the difference in pathogen inhibition between formulated and fresh probiotics was less than a logarithm. The final formula was tested in vivo and showed improved wound healing indicators. The optimized formula resulted in a higher rate of wound closure and infection clearance. Furthermore, the molecular studies for oxidative stress indicated that the formula could modify wound inflammatory responses. In histological investigations, the probiotic-loaded particles functioned exactly as efficaciously as silver sulfadiazine ointment did.
Subject(s)
Burns , Probiotics , Humans , Prebiotics , Wound Healing , Freeze Drying/methods , Burns/drug therapyABSTRACT
The antimicrobial property of stabilized silver nanoparticles (AgNPs) with phospholipid membrane was investigated on both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacterial strains. The influence of phospholipid concentrations on antibacterial kinetics actions of AgNPs was studied with two different methodologies in order to understand the bactericidal and bacteriostatic effects. The bacterial inactivation of synthesized AgNPs fitted well to the Chick-Watson model with a high regression coefficient, R(2) > 0.91. The antibacterial properties of AgNPs depend on the particle size, stabilizer and lecithin concentrations. Only the stabilized AgNPs that have the K(lec/Ag) values of 1 and 2 presented the inhabitation zone, while unstabilized AgNPs agglomerated quickly, settled on the wells and did not diffuse in agar. In addition, the specific coefficient of lethality depends on the lecithin concentration. An increase in lecithin concentration caused multilayer creation on the AgNPs' surface and reduced the release of AgNPs which led to low bacterial killing rate.
Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Metal Nanoparticles/chemistry , Phospholipids/chemistry , Silver/chemistry , Escherichia coli/drug effects , Microbial Sensitivity Tests , Staphylococcus aureus/drug effectsABSTRACT
A reliable and sensitive headspace solid-phase microextraction gas chromatography-mass spectrometry method for simultaneous determination of different organophosphorus pesticides in dried medicinal plant samples is described. The analytes were extracted by single-walled carbon nanotubes as a new solid-phase microextraction adsorbent. The developed method showed good performance. For diazinon and pirimiphos methyl calibration, curves were linear (r(2) ≥ 0.993) over the concentration ranges from 1.5 to 300 ng g(-1), and the limit of detection at signal-to-noise ratio of 3 was 0.3 ng g(-1). For parathion and malathion, the linear range and limit of detection were 2.5-300 (r(2) ≥ 0.991) and 0.5 ng g(-1), respectively. In addition, a comparative study between the single-walled carbon nanotubes and a commercial polydimethylsiloxane fibre for the determination of target analytes was carried out. Single-walled carbon nanotubes fibre showed higher extraction capacity, better thermal stability (over 350 °C), and longer lifespan (over 250 times) than the commercial polydimethylsiloxane fibre. The developed method was successfully applied to determine target organophosphorus pesticides in real samples.
Subject(s)
Diazinon/analysis , Malathion/analysis , Nanotechnology/methods , Nanotubes, Carbon/chemistry , Organothiophosphorus Compounds/analysis , Parathion/analysis , Calibration , Dimethylpolysiloxanes/chemistry , Limit of Detection , Organophosphorus Compounds/chemistry , Pesticides/chemistry , Plants, Medicinal , Reproducibility of Results , Solid Phase Microextraction , TemperatureABSTRACT
Geum iranicum Khatamsaz, belonging to the Rosaceae family, is an endemic plant of Iran. The methanol extract of the roots of this plant showed significant activity against one of the clinical isolates of Helicobacter pylori which was resistant to metronidazole. The aim of this study was the isolation and evaluation of the major compounds of G. iranicum effective against H. pylori. The compounds were isolated using various chromatographic methods and identified by spectroscopic data (1H and 13C NMR, HMQC, HMBC, EI-MS). An antimicrobial susceptibility test was performed employing the disk diffusion method against clinical isolates of H. pylori and a micro dilution method against several Gram-positive and Gram-negative bacteria; additionally the inhibition zone diameters (IZD) and minimum inhibitory concentrations (MIC) values were recorded. Nine compounds were isolated: two triterpenoids, uvaol and niga-ichigoside F1, three sterols, beta-sitosterol, beta-sitosteryl acetate, and beta-sitosteryl linoleate, one phenyl propanoid, eugenol, one phenolic glycoside, gein, one flavanol, (+)-catechin, and sucrose. The aqueous fraction, obtained by partitioning the MeOH extract with water and chloroform, was the most effective fraction of the extract against all clinical isolates of H. pylori. Further investigation of the isolated compounds showed that eugenol was effective against H. pylori but gein, diglycosidic eugenol, did not exhibit any activity against H. pylori. The subfraction D4 was the effective fraction which contained tannins. It appeared that tannins were probably the active compounds responsible for the anti-H. pylori activity of G. iranicum. The aqueous fraction showed a moderate inhibitory activity against both Gram-positive and Gram-negative bacteria. The MIC values indicated that Gram-positive bacteria including Staphylococcus aureus, Staphylococcus epidermidis, and Bacillus subtilis are more susceptible than Gram-neagative bacteria including Escherichia coli and Pseudomonas aeruginosa.
Subject(s)
Anti-Bacterial Agents/pharmacology , Geum/chemistry , Helicobacter pylori/drug effects , Methanol/chemistry , Plant Extracts/pharmacology , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Spectrometry, Mass, Electrospray IonizationABSTRACT
A bacteriocin-like inhibitory substance producing Lactococcus lactis subsp lactis strain, ST1, isolated from goat milk of Iranian origin and with broad spectrum of activity and desirable technical properties was used for evaluating some futures of bacteriocin inhibitory activity. Cell growth and bacteriocin production studies were carried out in MRS medium incubated statically under uncontrolled pH condition. The antibacterial activity presented a primary metabolite pattern and showed a rapid decrease at the stationary phase. Microaerobiosis and capnophily growth conditions resulted in higher bacteriocin production while aerobiosis showed negative effect on both cell growth and bacteriocin production. Bacteriocin production, on the other hand, was favored in MRS broth (pH; 6.5) inoculated with 0.1 ml l(-1) fresh culture when incubation was carried out at 30 °C. This indicated that the conditions resulted in higher levels of growth were frequently favoring bacteriocin production by ST1 as well. Decrease in activity, at the stationary growth phase, was much pronounced in favored growth condition. Nutrient depletion, deferent effect of low pH on bacteriocin production and/or protein degradation seemed more responsible for this phenomenon. The study also provided further data on new method for bacteriocin release from the cell wall of producer. It was clearly shown that both heating and ultrasound shock for 5 min at pH 2 could increase bacteriocin activity significantly. The release was more pronounced in the presence of 0.5% Tween80.
ABSTRACT
BACKGROUND AND THE PURPOSE OF THE STUDY: Piperazinyl quinolones such as ciprofloxacin, ofloxacin and levofloxacin are an important group of quinolone antimicrobials which are widely used in the treatment of various infectious diseases. In the present study, we synthesized a new series of levofloxacin derivatives and evaluated their antibacterial activities. METHODS: The N-substituted analogs of levofloxacin 6a-j were prepared by nucleophilic reaction of N-desmethyl levofloxacin 11 with thienylethyl bromide derivatives 8 or 9. All target compounds were tested using conventional agar dilution method in comparison to levofloxacin and N-desmethyl levofloxacin and their MIC values were determined against a panel of Gram-positive and Gram-negative bacteria. RESULTS: All compounds showed significant antibacterial activities against Gram-positive bacteria (MIC = 0.04-6.25 µg/mL); however, the activity against Gram-negative bacteria was lower (MIC = 1.56-100 µg/mL). As is evident from the data, oxime derivatives 6e, 6h and 6i are superior in inhibiting the growth of Gram-positive bacteria (MIC = 0.04-0.19 µg/mL), and their activities were found to be 5-25 times better than N-desmethyl levofloxacin 11 and equal or better than levofloxacin 4. CONCLUSION: We have designed and synthesized novel quinolone derivatives bearing functionalized thienylethyl moiety on the piperazine ring of levofloxacin. The results of antibacterial screening against Gram-positive and Gram-negative bacteria revealed that the introduction of functionalized thienylethyl moiety on the piperazine ring of levofloxacin can improve the activity against Gram-positive bacteria. Gram-positive bacteria are responsible for a wide range of infectious diseases, and rising resistance in this group is causing increasing concern. Thus, this study introduces structural features of levofloxacin scaffold for development of new candidates in the field of anti-Gram positive chemotherapy.
ABSTRACT
BACKGROUND AND THE PURPOSE OF THE STUDY: The purpose of this study was to prepare pegylated poly lactide-co-glycolide (PEG-PLGA) nanoparticles (NPs) loaded with roxithromycin (RXN) with appropriate physicochemical properties and antibacterial activity. Roxithromycin, a semi-synthetic derivative of erythromycin, is more stable than erythromycin under acidic conditions and exhibits improved clinical effects. METHODS: RXN was loaded in pegylated PLGA NPs in different drug;polymer ratios by solvent evaporation technique and characterized for their size and size distribution, surface charge, surface morphology, drug loading, in vitro drug release profile, and in vitro antibacterial effects on S. aureus, B. subtilis, and S. epidermidis. RESULTS AND CONCLUSION: NPs were spherical with a relatively mono-dispersed size distribution. The particle size of nanoparticles ranged from 150 to 200 nm. NPs with entrapment efficiency of up to 80.0±6.5% and drug loading of up to 13.0±1.0% were prepared. In vitro release study showed an early burst release of about 50.03±0.99% at 6.5 h and then a slow and steady release of RXN was observed after the burst release. In vitro antibacterial effects determined that the minimal inhibitory concentration (MIC) of RXN loaded PEG-PLGA NPs were 9 times lower on S. aureus, 4.5 times lower on B. subtilis, and 4.5 times lower on S. epidermidis compared to RXN solution. In conclusion it was shown that polymeric NPs enhanced the antibacterial efficacy of RXN substantially.
ABSTRACT
There is a special focus on using natural materials and herbal plants to prevent dental caries. Previous studies showed that some herbal plants have antimicrobial effects on oral pathogens. Thus we investigated the antimicrobial effects of three herbal extracts (Carum copticum, Phlomis bruguieri, and Marrubium parviflorum) on the growth of Streptococcus mutans, as the most important bacteria causing dental caries. First, plant methanolic extracts were prepared. Then, to evaluate the antimicrobial activity of the three herbal extracts, the agar well diffusion method and MIC were performed. The biofilm formation was carried out using a broth dilution method with 2% glucose-supplemented BHIS in sterile 96-well microplates. Serial dilutions (50, 25, 12.5, 6.25, 3.12 mg/ml) of extracts were prepared. Next, a 0.5 McFarland Suspension of S. mutans was added to wells. The inhibitory effect on biofilm formation was measured by the ELISA reader apparatus. The assay was repeated three times, and the average was calculated as 3. The results were compared with those of Chlorhexidine 0.2%. Carum copticum showed a better effect in the agar well diffusion method than others. MIC of the extracts of Carum coptimum, Phlomis bruguieri, and Marrubium parviflorum were 3.12, 6.25, and 12.5 mg/ml, respectively. Overall, the highest activity belonged to Carum copticum extract. For the anti-biofilm effect, the OD values of Carum copticum and Marrubium parviflorum were significantly different from that of Phlomis bruguieri. Although all of the methanolic herbal extracts can inhibit S. mutans growth and remove the biofilm, the effect of Carum copticum was better than Phlomis bruguieri and Marrubium parviflorum. Further studies are recommended to indicate how these extracts perform against the bacteria.