scholarly journals Polyketides from an Endophytic Aspergillus fumigatus Isolate Inhibit the Growth of Mycobacterium tuberculosis and MRSA

2015 ◽  
Vol 10 (10) ◽  
pp. 1934578X1501001 ◽  
Author(s):  
Andrew J. Flewelling ◽  
Amanda L Bishop ◽  
John A. Johnson ◽  
Christopher A. Gray
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Mycobacterium Tuberculosis ◽  
Aspergillus Fumigatus ◽  
Crude Extract ◽  
Antimycobacterial Activity ◽  
Methicillin Resistant ◽  
Bioassay Guided Fractionation ◽  
Chaetoglobosin A

The crude extract of Aspergillus fumigatus isolate AF3-093A, an endophyte of the brown algaFucus vesiculosus, showed significant antimicrobial activity in initial bioactivity screens. Bioassay-guided fractionation of the extract led to the isolation of flavipin, chaetoglobosin A and chaetoglobosin B, all of which inhibited the growth of Staphylococcus aureus, methicillin-resistant S. aureus and Mycobacterium tuberculosis H37Ra. The antimycobacterial activity of these compounds has not been previously reported.

scholarly journals Antimicrobial Metabolites against Methicillin-Resistant Staphylococcus aureus from the Endophytic Fungus Neofusicoccum australe

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1094
Author(s):  
Melissa M. Cadelis ◽  
Soeren Geese ◽  
Benedict B. Uy ◽  
Daniel R. Mulholland ◽  
Shara J. van de Pas ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Natural Products ◽  
Structure Elucidation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Spectroscopic Methods ◽  
Methicillin Resistant ◽  
Bioassay Guided Fractionation ◽  
Antimicrobial Metabolites

Antimicrobial bioassay-guided fractionation of the endophytic fungi Neofusicoccum australe led to the isolation of a new unsymmetrical naphthoquinone dimer, neofusnaphthoquinone B (1), along with four known natural products (2–5). Structure elucidation was conducted by nuclear magnetic resonance (NMR) spectroscopic methods, and the antimicrobial activity of all the natural products was investigated, revealing 1 to be moderately active towards methicillin-resistant Staphylococcus aureus (MRSA) with a minimum inhibitory concentration (MIC) of 16 µg/mL.

scholarly journals Pharmacodynamic Functions of Synthetic Derivatives for Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) and Mycobacterium tuberculosis

2020 ◽  
Vol 11 ◽  
Author(s):  
Mojdeh Dinarvand ◽  
Malcolm P. Spain ◽  
Fatemeh Vafaee
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Mycobacterium Tuberculosis ◽  
Antimicrobial Agents ◽  
Resistant Bacteria ◽  
Synthetic Compounds ◽  
Methicillin Resistant ◽  
Chemical Structures ◽  
Time Kill

Drug resistant bacteria have emerged, so robust methods are needed to evaluate combined activities of known antibiotics as well as new synthetic compounds as novel antimicrobial agents to treatment efficacy in severe bacterial infections. Marine natural products (MNPs) have become new strong leads in the drug discovery endeavor and an effective alternative to control infections. Herein, we report the bioassay guided fractionation of marine extracts from the sponges Lendenfeldia, Ircinia, and Dysidea that led us to identify novel compounds with antimicrobial properties. Chemical synthesis of predicted compounds and their analogs has confirmed that the proposed structures may encode novel chemical structures with promising antimicrobial activity against the medically important pathogens. Several of the synthetic analogs exhibited potent and broad spectrum in vitro antibacterial activity, especially against the Methicillin-resistant Staphylococcus aureus (MRSA) (MICs to 12.5 μM), Mycobacterium tuberculosis (MICs to 0.02 μM), uropathogenic Escherichia coli (MIC o 6.2 μM), and Pseudomonas aeruginosa (MIC to 3.1 μM). Checkerboard assay (CA) and time-kill studies (TKS) experiments analyzed with the a pharmacodynamic model, have potentials for in vitro evaluation of new and existing antimicrobials. In this study, CA and TKS were used to identify the potential benefits of an antibiotic combination (i.e., synthetic compounds, vancomycin, and rifampicin) for the treatment of MRSA and M. tuberculosis infections. CA experiments indicated that the association of compounds 1a and 2a with vancomycin and compound 3 with rifampicin combination have a synergistic effect against a MRSA and M. tuberculosis infections, respectively. Furthermore, the analysis of TKS uncovered bactericidal and time-dependent properties of the synthetic compounds that may be due to variations in hydrophobicity and mechanisms of action of the molecules tested. The results of cross-referencing antimicrobial activity, and toxicity, CA, and Time-Kill experiments establish that these synthetic compounds are promising potential leads, with a favorable therapeutic index for antimicrobial drug development.

scholarly journals PREPARATION OF COLD CREAM AGAINST CLINICAL PATHOGEN USING CARALLUMA ADSCENDENS VAR. ATTENUATA

2020 ◽  
pp. 120-123
Author(s):  
SUNDAR MADASAMY ◽  
SURESH SUNDAN ◽  
LINGAKUMAR KRISHNASAMY
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Positive Control ◽  
Diffusion Method ◽  
Methicillin Resistant ◽  
Cold Cream ◽  
Significant Difference ◽  
Vancomycin Resistant

Objective: A simple formulation of cold cream from methanolic extract Caralluma adscendens var. attenuata (MECA) and their antimicrobial activity was tested against various clinical pathogens, namely, Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and Candida albicans. Methods: Methanol extract of these plant extract was prepared by the Soxhlet method. We analyzed phytochemical nature of theses plant, and subsequently, a cream was formulated cold-cream C. adscendens var. attenuata (FCA) different concentration such as FCA 50 mg, FCA 100 mg, and FCA 200 mg. In the present study, aimed to the antimicrobial activity of cold cream was measured by agar well diffusion method, and standard antibiotic Neosporin (market available) cream was used as positive control and dummy cold cream (without-MECA) were used as the negative control. Results: Phytochemical screening showed that the plant extracts were found a rich source of secondary metabolites. For more, the efficacy of cold cream from MECA extracts to against the clinical pathogen. Positive control Neosporin and 200 mg FCA cream was a highly significant difference in the zone of inhibition when compared to dummy cream. The 200 mg FCA was activity against Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant E. faecium, and C. albicans highly significantly difference (p<0.05) compared FCA 50 mg and FAC 100 mg creams. Conclusion: The results from this study suggested that the cold cream form base of MECA crude had antimicrobial activity in the different clinical pathogen. They could be used as an alternative source to conventional antimicrobial agents for the treatment of pathological infection.

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