scholarly journals From bugs to drugs: Combating antimicrobial resistance by discovering novel antibiotics

2018 ◽  
Vol 12 (02.1) ◽  
pp. 3S
Author(s):  
Antoine Abou Fayad ◽  
Dana Itani ◽  
Mariam Miari ◽  
Arax Tanelian ◽  
Sereen Iweir ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Antimicrobial Resistance ◽  
Soil Microorganisms ◽  
Soil Samples ◽  
16S Rrna Analysis ◽  
Strain Isolation ◽  
Bacillus Subtilis Atcc ◽  
Novel Antibiotics

Introduction: Antimicrobial resistance (AMR) is emerging at an alarming rate as mortality due to resistant pathogens could rise to 10 million per year by 2050. Since AMR is against all clinically utilized antibiotics, finding novel antimicrobials with unexploited targets remains the main goal worldwide.  Soil microorganisms produce natural products as a significant number of drugs in clinical use are derived from these metabolites. Actinomycetes and Myxobacteria are soil dwelling microorganisms that produce secondary metabolites to be screened for antibacterial activity. More than 80% of clinically utilized antibiotics are either natural products or natural product-derived molecules such as vancomycin, teicoplanin, daptomycin, and tetracycline. This study aims to isolate and identify novel antimicrobials from Actinomycetes and Myxobacteria. Methodology: Soil samples were collected from several areas in Lebanon. Samples were serially diluted for Actinomycetes isolation and boiled for Myxobacteria extraction, then plated on suitable media. Colonies obtained were purified and subjected to genomic DNA extraction then 16s rRNA analysis. Novel isolates were tested for their antimicrobial activity against Gram-positive Bacillus subtilis (ATCC 6051), Staphylococcus aureus (ATCC 29213, Newman, N315), Enterococcus faecalis (ATCC 19433), and Enterococcus faecium (DSMZ 17050), and Gram-negative Escherichia coli (ATCC 9637), Klebsiella pneumoniae (DSMZ), Pseudomonas aeruginosa (ATCC 27853, MEXAB), and Acinetobacter baumannii (ATCC 15308). Results: Strain isolation and cultivation yielded a number of novel isolates whose extracts demonstrated strong antibacterial activity against pathogens including MRSA, VRE, and Escherichia coli (ATCC 9637). Conclusion: Our efforts now focus on purifying these compounds, elucidate their structures and study their mode of action.

scholarly journals Synergizing the potential of bacterial genomics and metabolomics to find novel antibiotics

2021 ◽  
Author(s):  
Fabian Panter ◽  
Chantal D. Bader ◽  
Rolf Müller
Keyword(s):  
Natural Products ◽  
Antimicrobial Resistance ◽  
Public Concern ◽  
Bacterial Genomics ◽  
Technological Developments ◽  
Novel Antibiotics

Antimicrobial resistance is a major public concern and novel antibiotics are largely based on natural products. We summarize recent analytical and genome based technological developments that gain increasing importance in the natural products field.

scholarly journals ISOLATION AND CHARACTERIZATION OF ACTINOMYCETES FROM SOIL OF AD-DAWADMI, SAUDI ARABIA AND SCREENING THEIR ANTIBACTERIAL ACTIVITIES

2017 ◽  
Vol 9 (10) ◽  
pp. 276 ◽  
Author(s):  
Gouse Basha Sheik ◽  
Muazzam Sheriff Maqbul ◽  
Gokul Shankar S. ◽  
Ranjith M S
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antibacterial Activities ◽  
Soil Samples ◽  
Streptomyces Sp ◽  
Crude Extracts ◽  
Test Organisms ◽  
Inhibition Zones

Objective: To isolate and characterize novel actinomycetes and to evaluate their antibacterial activity against drug-resistant pathogenic bacteriaMethods: In the present study, 19 soil samples were collected from different localities of Ad-Dawadmi, Saudi Arabia. Actinomycetes were isolated from these samples using serial dilution and plating method on Actinomycetes isolation agar supplemented with nalidixic acid and actidione to inhibit bacteria and fungi. Crude extracts of potential actinomycetes were produced by submerged fermentation. The antimicrobial activity of crude extracts of actinomycetes was tested against different bacteria using the agar well diffusion method. Characterization of the isolates was done by morphological, physiological and biochemical methods.Results: A total of 9 (47%) isolates of actinomycetes were isolated from 19 different soil samples tested. Among them, 4 (44%) isolates confirmed as Streptomyces sp. showed potential antimicrobial activity against one or more test organisms. Crude extracts were made from these 4 actinomycetes isolates(DOM1, DOM3, DP3, DP4)and tested for their antibacterial activities against 4 different clinical bacterial strains (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus). Crude extract from DP3 isolate showed highest antibacterial activity against all the four test organisms (28 mm, 21 mm, 20 mm and 18 mm) respectively and DP4 showed lowest antibacterial activity against all the four test organisms (14 mm, 12 mm, 0 mm, 6 mm) respectively. The highest zone of inhibition was shown by DP3 against Staphylococcus aureus (28 mm) and Escherichia coli was resistant for DP4. Most of the Inhibition zones produced by crude extracts showed significant differences when compared with control, tested against test organisms (P<0.05). Inhibition zones produced by DP3 and DOM1 against Staphylococcus aureus were 28 mm and 23 mm, respectively which were strong active when compared with control Ciprofloxacin (18 mm).Conclusion: Further studies for purification of bioactive metabolites and molecular characterization analysis of isolated Streptomyces sp. are in progress which would be helpful in discovering novel compounds of commercial value.

scholarly journals EVALUATION OF ANTIBACTERIAL ACTIVITY OF A CYANOBACTERIUM SCYTONEMA SCHMIDTII GOM

2021 ◽  
pp. 77-79
Author(s):  
Janardhan Namdeo Nehul
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Methanol Extract ◽  
Axenic Culture ◽  
Soil Samples ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Zone Of Inhibition ◽  
Disc Diffusion Method ◽  
Air Blower

Scytonema schmidtii,a cyanobacterium was isolated from the collected soil samples from different locations of Ahmednagar district of Maharashtra state (India). Identification was carried out using morphological variation and taxonomical approaches according to Desikachary (1959) and Prescott (1962) .The axenic culture of Scytonema schmidtii was obtained by using the method recommended by Bolch and Blackburn (1996). The isolated Scytonema schmidtii was grown autotropically in BG-11 medium as described by Rippka et al.,(1979) and incubated at 30±2°c.After 25 days, biomass was harvested by filtration through double layered muslin cloth and dried using air blower. The biomass of this Scytonema schmidtii species was used for the assessment of antibacterial activity against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Micrococcus flavus and Proteus mirabilis. The antibacterial activity was studied by disc diffusion method (Anonymous,1996).Methanol extract of Scytonema schmidtii showed the activity against all the tested bacterial strains.Maximum zone of inhibition (23±1.9 mm) was recorded with methanol extract of Scytonema schmidtii.

scholarly journals Eugenia uniflora L.: potential uses as a bioactive plant

2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Gabriela Silva Moura ◽  
Ivan Júnior de Oliveira ◽  
Lisandro Tomas da Silva Bonome ◽  
Gilmar Franzener
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Total Phenolics ◽  
Antioxidant Compounds ◽  
Review Of The Literature ◽  
Bioactive Substances ◽  
Eugenia Uniflora

ABSTRACT: Natural products extracted from plants have always played an important role in the discovery of bioactive substances. This work carried out a review of the literature on the bioactive activities of Eugenia uniflora L. (Surinam cherries), as a potential plant in the various uses, be it medicinal, antimicrobial, antioxidant, insecticide and protective. In the literature, studies were found to confirm the antibacterial activity of E. uniflora leaves extract on Streptococcus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The presence of antioxidant compounds as total phenolics, such as anthocyanins and flavonoids, induction in the protection of plants by phytoalexins, as well as insecticidal and anthelmintic effects by the use of the extract of the E. uniflora tree. Although these different potential biotics of E. uniflora have already been reported, further studies are still needed on the use of natural products extracted from E. uniflora for employment for different purposes.

scholarly journals Fate of Escherichia coli O157:H7 in Manure-Amended Soil

2002 ◽  
Vol 68 (5) ◽  
pp. 2605-2609 ◽  
Author(s):  
Xiuping Jiang ◽  
Jennie Morgan ◽  
Michael P. Doyle
Keyword(s):  
Escherichia Coli ◽  
Soil Temperature ◽  
Soil Microorganisms ◽  
Soil Samples ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Contributory Factors ◽  
Pathogen Populations ◽  
Antagonistic Interactions ◽  
Amended Soil

ABSTRACT Escherichia coli O157:H7 cells survived for up to 77, >226, and 231 days in manure-amended autoclaved soil held at 5, 15, and 21°C, respectively. Pathogen populations declined more rapidly in manure-amended unautoclaved soil under the same conditions, likely due to antagonistic interactions with indigenous soil microorganisms. E. coli O157:H7 cells were inactivated more rapidly in both autoclaved and unautoclaved soils amended with manure at a ratio of 1 part manure to 10 parts soil at 15 and 21°C than in soil samples containing dilute amounts of manure. The manure-to-soil ratio, soil temperature, and indigenous microorganisms of the soil appear to be contributory factors to the pathogen's survival in manure-amended soil.

scholarly journals New Antibacterial Bagremycins F and G from the Marine-Derived Streptomyces sp. ZZ745

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 330 ◽  
Author(s):  
Di Zhang ◽  
Chenyan Shu ◽  
Xiaoyuan Lian ◽  
Zhizhen Zhang
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Spectroscopic Analysis ◽  
Optical Rotation ◽  
Marine Microorganisms ◽  
Streptomyces Sp ◽  
Bioactive Natural Products ◽  
Marine Actinomycete

As part of our research to discover novel bioactive natural products from marine microorganisms, five bagremycin analogues, including the previously unreported bagremycins F (1) and G (2), were isolated from a marine actinomycete Streptomyces sp. ZZ745. The structures of these compounds were determined by means of NMR spectroscopic analysis, HRESIMS data, and optical rotation. Both bagremycins F (1) and G (2) showed antibacterial activity against Escherichia coli, with MIC values of 41.8 and 61.7 μM, respectively.

scholarly journals Modulation of the Antibiotic Activity by Extracts fromAmburana cearensisA. C. Smith andAnadenanthera macrocarpa(Benth.) Brenan

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Fernando G. Figueredo ◽  
Emerson O. Ferreira ◽  
Bruno F. F. Lucena ◽  
Cícero M. G. Torres ◽  
Daniel L. Lucetti ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Inhibitory Concentration ◽  
Antibiotic Activity ◽  
Subinhibitory Concentration ◽  
Antimicrobial Drugs ◽  
Ethanol Extracts ◽  
Multiresistant Strains

The aim of this study was to verify the possible interactions between ethanol extracts ofAmburana cearensisA. C. Smith andAnadenanthera macrocarpa(Benth.) Brenan, combined with six antimicrobial drugs against multiresistant strains ofStaphylococcus aureusandEscherichia coliisolated from humans. The antibacterial activity of the extracts was determined using the minimum inhibitory concentration (MIC). The microdilution assay was performed to verify the interactions between the natural products and the antibiotics using a subinhibitory concentration. The activity of amikacin associated with the extract ofAnadenanthera macrocarpaagainst EC 27 was enhanced, demonstrating an MIC reduction from 128 to 4 μg/mL. Among theβ-lactams, no potentiation on its activity was observed, with exception to the antagonism of the natural products with ampicillin againstS. aureus358.

scholarly journals Antimicrobial and Chemical Studies on a Medicinally important Plant: Curcuma longa

2021 ◽  
Author(s):  
◽  
Hadeel Alhazmi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Methanolic Extract ◽  
Curcuma Longa ◽  
Positive Bacterium ◽  
African Countries ◽  
Gram Positive ◽  
Gram Negative

This thesis describes phytochemical studies on the methanolic extract of Curcuma longa; a medicinally important plant used as indigenous medicine for the treatment of wounds in South Asian and African countries. The crude extract displayed antibacterial activity against the Gram-positive bacterium, Staphylococcus aureus, but was inactive against Gram-positive bacterium Streptococcus agalactiae. This extract also did not show antibacterial activity against Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa. Based on the observed antibacterial activity, it was decided to carry out phytochemical investigation of crude methanolic extract of C. longa to isolate and characterize natural products and evaluate them for antimicrobial activity. These efforts resulted in the identification of three known natural products: curcumin (39) sclareolide (40) and atalantoflavone (41). Structures of these compounds were established with the aid of NMR spectroscopic studies. Compounds (40) and (41) have been isolated for the first time from this plant. Compounds (39-41) were found to be inactive against the Gram-positive bacterium, Staphylococcus aureus, and Gram-negative bacterium, Escherichia coli.

Two Epimeric Flavalignans from Trichilia catigua (Meliaceae) with Antimicrobial Activity

2002 ◽  
Vol 57 (5-6) ◽  
pp. 483-488 ◽  
Author(s):  
Moacir G. Pizzolatti ◽  
Andreia F. Venson ◽  
Artur Smânia Júnior ◽  
Elza de F. A. Smânia ◽  
Raimundo Braz-Filho
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Natural Products ◽  
Bacillus Cereus ◽  
Spectroscopic Data ◽  
2D Nmr ◽  
And Staphylococcus Aureus

A mixture of flavalignan cinchonains Ia and Ib was isolated from the bark of Trichilia catigua. The structures were established on the basis of spectroscopic data of the natural products and their methylated derivatives including 2D NMR experiments, and compared with data in the literature. These flavalignans exhibited antibacterial activity against Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.

scholarly journals Purpurin Esters Containing a Saturated Cyclic Fragment with Antimicrobial Activity

2020 ◽  
Vol 22 (1) ◽  
pp. 43 ◽  
Author(s):  
Т.V. Kharlamova ◽  
R.B. Seidakhmetova ◽  
K.D. Praliyev
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Acid Chlorides ◽  
Bacillus Subtilis Atcc ◽  
Cyclic Fragment ◽  
Mic Value

The present study is a continuation of the scientific research works for the synthesis of anthraquinonе-containing derivatives with cyclic ring systems by the interaction of 1,2,4-trihydroxyanthraquinone (purpurin) with cyclic carboxylic acid chlorides. Series of purpurin esters containing a saturated cyclic fragment was studied for antibacterial activity about museum strains of microorganisms. The effects of these preparations in vitro about Staphylococcus aureus ATCC 6538, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 25922, Pseudomonas aeruginosa АТСС 27853 and fungus Сandida albicans АТСС 10231 were studied. It has been found that the compounds with the cyclohexane fragment have possess an antimicrobial activity with strains of microorganisms Staphylococcus aureus АТСС 6538 for which the MIC value was 31.25 μg/ml.

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