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    Invitro antibacterial activity of imidazole and triazole-based antimicrobials against Carbapenem Resistant Enterobacteriaceae
    (2019-09-05) Radebe, Siyabonga Protus; Ndlovu, Thandie Sylph
    Introduction The frequency of serious bacterial infections has increased due to the high prevalence of HIV infection, contributing to the increasing rates of multi-drug organisms which include carbapenem-resistant Enterobacteriaceae (CRE). This trend has become a serious challenge to the health care system of South Africa, resulting in the higher use of immunosuppressive and cytotoxic drugs to treat serious bacterial infections. Optimal treatment for infections caused by CRE is yet unknown. The benefits of imidazole and triazole antimicrobials have become very topical due their diverse spectrum of pharmacological properties, but its efficacy against bacterial infections has not been tested in the South African context. Aim The primary aim of this study was to determine the antibacterial effects of selected imidazole and triazole-based antimicrobials against Carbapenem-Resistant Enterobacteriaceae. Methodology Different concentrations of test drugs (ketoconazole, metronidazole and fluconazole) were used to prepare sensitivity disks and four pathogenic strains of Carbapenem Resistant Enterobacteriaceae (K. pneumonia, E. coli, S. marcescens and C. freundii) obtained from Lancet Laboratory in Durban were used to determine the antibacterial activity of the selected test drugs, using Disk Diffusion, Modified Agar Diffusion and Minimum Inhibition Concentration (MIC) method, described by Bauer et al. 1966. Results Antimicrobial Susceptibility Testing revealed that, test drugs selected for this study have no inhibition activity against CRE test organisms and biochemical tests also showed that imidazole and triazoles antimicrobials have no adverse effects on the CRE organisms. Conclusion Although the results obtained in this study indicated no activity of against CRE, laboratory studies are still necessary in modification of the imidazole and triazoles to synthesize derived drugs to confirm and optimize the antibacterial potency of these compounds.
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    The efficacy of Calendula officinalis tincture as an antibacterial on in vitro Pseudomonas aeruginosa
    (2002) Mabuza, Mbuso; Ross, Ashley Hilton Adrian; Sturm, A. W.
    The aim of this in vitro microbial study was to evaluate the efficacy of Calendula officinalis tincture 60% (v/v) ethanol as an antibacterial on in vitro Pseudomonas aeruginosa. The standardised disc - diffusion method was employed. Seven pairs of Mueller - Hinton agar plates were used.
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    A controlled in vitro study of the effectiveness of Tulbagia Violacea in herbal tincture and homoeopathic dilution (1X and 6X) against gram- positive and gram negative bacteria
    (2002) Invernizzi, Jonathan Reuben Rai; Steele, Richard
    The purpose of this study was to determine the effect that Tulbagia violacea ethanolic herbal tincture, and Tulbagia violacea IX and 6X homoeopathic potencies, had 011 the in vitro growth inhibition of Escherichia coli, Klebsiella pneumoniae, Staphylococcus ourens. Pseudomonas aeruginosa and Bacil/us cereus respectively, as compared to a ethanol negative control. The final results were expressed as a ratio to the values obtained from gentamyein and vancomycin. Measurement was by means of the discdiffusion assay. For this study fifteen Mueller-Hinton agar plates were prepared and inoculated with each test bacteria in turn. Filter paper discs were individually inoculated with the sample substances and the control using a micropipette, before being allowed to air dry, One disc each of the Tulbagia violacea herbal tincture, 1X potency, 6X potency, ethanol control, as well as a gentamyein and vancomycin disc were placed equidistantly apart on each plate, The gentamyein and vancomycin discs were included in the experiment with the sole purpose of accounting for plate-to-plate variations in the pharmacological sensitivity of the same species of bacteria, The plates were incubated at 37\xB0C, and the zones of inhibitions measured with a pair of Vernier callipers at ] 8 hour, 24 hour and 36 hour intervals. Il Data entry and analysis was done using the SPSS\xAE statistical package, The Friedman test was used for intra-group comparison of each test or control substance at 18 hours, 24 hours and 36 hours. The Mann-Whitney U test was used to compare the mean inhibition zones produced by the test and control substance after 18 hours, 24 hours and 36 hours of incubation. The tests were performed at a=O.05 (5%) level of significance, The results obtained were that the Tulbagia violacea herbal tincture, and IX and 6X nomoeopathic potencies did not produce a statistically significant inhibitive effect on
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    A controlled in vitro study of the effectiveness of Alepidea amatymbica herbal tincture and homoeopathic dilutions (01 and 06) against Gram-positive and Gram-negative bacteria
    (2003) Williams, Dillon Christopher; Steele, Richard
    The purpose of this study was to determine the efficacy of Alepidea amatymbica tincture and homoeopathic dilutions to the 1st and 6th decimal potency as compared to ethanol (negative control) in the in vitro inhibition of Escherichea coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Bacillus cereus in terms of the disc diffusion test. Vancomycin and gentamicin were included in the study as positive controls in order to account for plate-ta-plate variations in the sensitivity of the bacterial strains to antimicrobial substances. Antimicrobial activity was expressed as the ratio of the inhibition zone (mm) produced by the test substance and the inhibition zone (mm) produced by the two combined antibiotic discs. For this study 20 Mueller-Hinton agar plates were assigned to each bacterial species and were inoculated with their respective bacteria. Four dry filter paper discs and two antibiotic discs were placed equidistantly on each agar plate. The filter paper discs had been previously impregnated with one of the test substances or the negative control using a triple impregnation technique utilizing a micro-pipette. The plates were then incubated at 37\xB0 C. The diameters of the zones of inhibition were measured at 18 hours, 24 hours and 48 hours. Data was analysed by means of the Statistical Package for Social Sciences (SPSS). Statistical methods utilized were Friedmans' test, Mann-Whitney U test, and Kruskall - Wallis Non-Parametric Analysis of Variance by Rank test.
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    The efficacy of thymus vulgaris tincture as an antibacterial agent
    (2002) Vosloo, Chiquita; Steele, Richard
    The aim of this study was to establish the effect of Thymus vulgaris tincture prepared in 43% ethanol and 70% ethanol in comparison to 43% ethanol and 70% ethanol only upon Streptococcus pyogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, Escherichia coli and Enterococcus faecalis, using a disc diffusion method, and to determine the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MEC) of Thymus vulgaris tincture in respect of these bacteria. Mueller-Hinton agar plates were streaked with saline test cultures adjusted to the 0.5 McFarland Equivalence Turbidity Standard. Five sterile filter paper discs 5mm in diameter were placed on each plate. These filter paper discs were impregnated with 10111of the test or control substances using a micropipette. The plates were incubated at 3TC for 18 hours. The diameters of the zones of inhibition of the bacterial growth around the discs were measured. This data was used to look for inter-group change by means of the Mann- Whitney Test between the test and control subgroups in both group A and group B. The means and standard deviations of each of the groups were compared in order to look for possible trends if the p-value of each group was insignificant. Il Thymus vulgaris tincture in 43% ethanol produced significant inhibitory effects in comparison to the 43% ethanol control upon all the bacteria tested. Thymus vulgaris tincture in 70% ethanol produced significant inhibitory effects in comparison to the
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    In vitro antidiabetic and antimicrobial properties of Ocimum species (Ocimum basilicum and Ocimum sanctum) (L.)
    (2016) Malapermal, Veshara; Mtshali, Joyce Nonhlanhla; Naidu, K. Suresh Babu; Botha, Izel
    Introduction In Africa, use of phytotherapy for treatment of diabetes mellitus is a common form of practice. Considering the increasing burden of non-communicable diseases in South Africa efforts are directed at simple, cost effective, non-hazardous and efficient methods to treat cancer, cardiovascular diseases and diabetes. The role of phytonanotherapy is an attractive proposition for advancing new therapies. Metal nanoparticles are a possible means for delivery of such therapies. However, this requires investigation on interactions, mechanisms and therapeutic efficacy upon co-administering ethnobotanicals with metal nanoparticles and existing drug therapy in human beings. Aim The primary aim of the study was to test the in vitro antidiabetic and antibacterial activity of Ocimum sanctum (leaf extracts and flower extracts), Ocimum basilicum (leaf extracts and flower extracts), and a combination of the leaf extracts of both, and to observe whether any antidiabetic and antibacterial activity was enhanced in due to phyto-synthesised bimetallic gold-silver (Au-Ag) nanoparticles and silver nanoparticles. Methods Aqueous and ethanol extracts of O. sanctum and O. basilicum leaf and flowers alone and combined (leaf + flower) were prepared using hot vs cold water extraction techniques and 60% and 70% ethanol as polar solvents. A simple, rapid, cost effective and reproducible green chemistry method synthesised alloyed bimetallic (Au-Ag) nanoparticles using O. basilicum leaf and flower aqueous extracts and prepared silver nanoparticles (AgNps) using O. basilicum and O. sanctum leaf aqueous extracts singly and in combination (O. sanctum + O. basilicum). The size, shape and elemental analysis of the nanoparticles was carried out using UV-Visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy coupled with energy-dispersive X-ray (SEM-EDX), dynamic light scattering (DLS) and zeta potential. Fourier transform infrared spectroscopy (FT-IR) supported by gas chromatography mass spectroscopy (GC-MS) identified the bio-capping agents. Antidiabetic carbohydrate metabolising enzymes, α-amylase (porcine) and Bacillus stearothermophilus α-glucosidase as models tested the in vitro inhibitory potential of the aqueous and ethanol plant extracts and the phyto-synthesised (Au-Ag) bimetallic and AgNps. In addition, the study investigated the antibacterial potential for the aqueous plant preparations and their respective phyto-synthesised bimetallic and AgNps against the bacterial species Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella species and Pseudomonas aeruginosa compared to gentamycin and vancomycin. Results Bimetallic nanoparticles (synthesised from leaf and flower aqueous extracts) displayed inhibitory activity that showed uncompetitive inhibition (leaf extract), and non-competitive inhibition (flower extract) of α-amylase and competitive (leaf extract) and uncompetitive inhibition (flower extract) of α-glucosidase. Bimetallic nanoparticles were higher in inhibitory activity than acarbose and the crude O. basilicum ethanol and aqueous leaf and flower extracts. In the antibacterial analysis, bimetallic nanoparticles derived from O. basilicum leaf showed inhibition against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa and were greater in activity compared to the crude aqueous leaf extract from O. basilicum. The in vitro inhibitory effect of AgNps derived from O. sanctum and AgNps derived from O. basilicum on both enzymes was higher in activity than acarbose and their respective crude extracts. However, in combination (O. sanctum + O. basilicum), the derived AgNps appeared to be a less potent inhibitor of α-amylase and α-glucosidase enzyme and was lower than acarbose. AgNps synthesised from the combination of O. sanctum and O. basilicum showed the highest percentage inhibition against Bacillus stearothermophilus α-glucosidase, and AgNps derived from O. sanctum and AgNps derived from O. basilicum displayed competitive type of inhibition. In the antibacterial analysis, AgNps derived from the various extracts showed zones of inhibition against the Gram negative and Gram positive bacterial test strains. However, AgNps synthesised from the O. sanctum leaf extract showed higher inhibition against Escherichia coli than the positive control gentamycin and higher inhibition against Staphylococcus aureus compared to vancomycin. In addition, AgNps from O. sanctum leaf extract displayed inhibition against Bacillus subtilis, Pseudomonas aeruginosa and Salmonella species, thus representing the highest antibacterial potential. Conclusion The results demonstrate the possibility of synthesis of stable silver and bimetallic nanoparticles of Ocimum sp. The synthesised silver nanoparticles and first time synthesis of bimetallic (Au-Ag) nanoparticles displayed enhanced antihyperglycaemic properties compared to their respective crude extracts and, therefore, show promising effects in lowering postprandial hyperglycaemia in diabetic patients with dual potential for antibacterial treatment. However, the antidiabetic and antibacterial effect will need to be further affirmed in a clinical context. Medicinal plants with therapeutic value may create a new platform for further research to explore the potential for herbal medicine and nanoscience as effective biomedical and industrial applications, and for improving existing drug delivery systems in diabetic patients. Investigations into the cytotoxicity of these extracts and phytosynthesised nanoparticles is recommended.