scholarly journals Potential Antimicrobial Activity of Galloyl-Flavonoid Glycosides From Woodfordia uniflora Against Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 12 ◽  
Author(s):  
Jae Sik Yu ◽  
Ji-Hoon Kim ◽  
Luay Rashan ◽  
Inseo Kim ◽  
Wonsik Lee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Natural Products ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Flavonoid Glycosides ◽  
Phytochemical Analysis ◽  
Antimicrobial Compounds ◽  
Ongoing Research ◽  
Methicillin Resistant ◽  
Bioactive Natural Products

Antibiotic-resistant infections are a growing problem; to combat multi-drug resistant bacterial infections, antibiotics with novel mechanisms of action are needed. Identification of potent bioactive natural products is an attractive avenue for developing novel therapeutic strategies against bacterial infections. As part of our ongoing research to explore bioactive natural products from diverse resources, we investigated the antimicrobial compounds from Woodfordia uniflora, a flowering shrub unique to the Dhofar region of Oman. The plant has been used as a remedy for skin infections in Oman. However, to date, no study has examined the antimicrobial compounds in W. uniflora. Phytochemical analysis of the methanolic extract of W. uniflora leaves in combination with LC/MS-based analysis allowed us to isolate and identify four flavonoid-type analogs (1–4), procyanidin B3-3-O-gallate (1), rhamnetin 3-O-(6″-galloyl)-β-D-glucopyranoside (2), rhamnetin 3-O-α-L-rhamnopyranoside (3), and quercetin 3-O-(6″-galloyl)-β-D-glucopyranoside (4). The isolates have a novel mechanism of action; the compounds inhibit biofilm formation in methicillin-resistant Staphylococcus aureus (MRSA) and synergize with methicillin. Our metabolite analysis revealed that this synergizing activity by compounds was achieved by remodeling metabolism including central carbon metabolism and glutamine biosynthesis that resulted in abnormal cell formation and reduction in biofilm formation of MRSA. Taken together, these findings provide experimental evidence that rhamnetin 3-O-(6″-galloyl)-β-D-glucopyranoside (2) and quercetin 3-O-(6″-galloyl)-β-D-glucopyranoside (4) can be considered as potential therapeutic agents for the treatment of methicillin-resistant S. aureus-associated diseases.

scholarly journals Discovery of the Antibiotic Polyketide Tatiomicin via a Genomics Guided Analysis of Amycolatopsis sp. DEM30355

2020 ◽  
Author(s):  
Bernhard Kepplinger ◽  
Joseph Cowell ◽  
Stephanie Morton-Laing ◽  
Corinne Wills ◽  
Emma Marrs ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Natural Products ◽  
Computational Methods ◽  
Antibiotic Activity ◽  
Structural Elucidation ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Stereochemical Assignment ◽  
Bioactive Natural Products ◽  
Gram Positive Bacteria

The application of genomic techniques to the investigation of understudied species of actinobacteria provides an expedited route to the discovery of new bioactive natural products. We report the isolation of the antibiotic polyketide tatiomicin, through a genomics and bioactivity informed analysis of the metabolome of the extremophile <i>Amycolatopsis</i> sp. DEM30355. Structural elucidation including absolute stereochemical assignment was performed using complementary crystallographic, spectroscopic and computational methods. Tatiomicin shows antibiotic activity against Gram-positive bacteria, including Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA).

scholarly journals Wood-decaying fungi found in Ghana: A rich source of new anti-infective compounds

2019 ◽  
Vol 2 ◽  
pp. 20
Author(s):  
Samuel Yaw Aboagye ◽  
Vincent Amarh ◽  
Paul A. Lartey ◽  
Patrick Kobina Arthur
Keyword(s):  
Antimicrobial Activity ◽  
Natural Products ◽  
Drug Discovery ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Significant Proportion ◽  
Microbial Pathogens ◽  
Antimicrobial Compounds ◽  
Bioactive Natural Products ◽  
Test Organisms

Background: Discovery of bioactive natural products are instrumental for development of novel antibiotics. The discovery and development of natural products such as penicillin represented a major milestone in the treatment of bacterial infections. Currently, many antibiotics have lost their relevance in clinics due to the emergence of drug-resistant microbial pathogens. Hence, there is the need for continuous search of new compounds endowed with potent antimicrobial activity. Methods: In this study, wood-decaying fungi (WDF) from Ghana were explored for their potential as sources of novel antimicrobial compounds with intent of expanding the effort into a drug discovery programme in the near future. Extracts from cultures of 54 morphologically distinct WDF isolates were analyzed for the presence of antimicrobial agents. Results: The extracts from 40 out of the 54 WDF isolates exhibited significant antimicrobial activity against either Staphylococcus aureus, Escherichia coli or Candida albicans. Fractionation of these bioactive extracts, followed by bioassay of the organic fractions obtained, indicate that extracts exhibiting antimicrobial activity against more than one of the three test organisms could be attributed to the presence of different bioactive compounds. Analysis of the composition of the extracts revealed that terpenes were predominant. Conclusions: This study suggests that a significant proportion of WDF in Ghana produce antimicrobial compounds which could be potential sources of novel anti-infective agents and support the plans of developing a drug discovery programme in Ghana based on the fermentation of WDF.

scholarly journals Discovery of the Antibiotic Polyketide Tatiomicin via a Genomics Guided Analysis of Amycolatopsis sp. DEM30355

2020 ◽  
Author(s):  
Bernhard Kepplinger ◽  
Joseph Cowell ◽  
Stephanie Morton-Laing ◽  
Corinne Wills ◽  
Emma Marrs ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Natural Products ◽  
Computational Methods ◽  
Antibiotic Activity ◽  
Structural Elucidation ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Stereochemical Assignment ◽  
Bioactive Natural Products ◽  
Gram Positive Bacteria

The application of genomic techniques to the investigation of understudied species of actinobacteria provides an expedited route to the discovery of new bioactive natural products. We report the isolation of the antibiotic polyketide tatiomicin, through a genomics and bioactivity informed analysis of the metabolome of the extremophile <i>Amycolatopsis</i> sp. DEM30355. Structural elucidation including absolute stereochemical assignment was performed using complementary crystallographic, spectroscopic and computational methods. Tatiomicin shows antibiotic activity against Gram-positive bacteria, including Methicillin-resistant <i>Staphylococcus aureus</i> (MRSA).

scholarly journals 5-Dodecanolide interferes with biofilm formation and reduces the virulence of Methicillin-resistant Staphylococcus aureus (MRSA) through up regulation of agr system

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alaguvel Valliammai ◽  
Sivasamy Sethupathy ◽  
Arumugam Priya ◽  
Anthonymuthu Selvaraj ◽  
James Prabhanand Bhaskar ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Pcr Analysis ◽  
High Morbidity ◽  
Healthy Human ◽  
Methicillin Resistant ◽  
Gene Expression Studies ◽  
Human Infections

Abstract Methicillin resistant Staphylococcus aureus (MRSA) is a predominant human pathogen with high morbidity that is listed in the WHO high priority pathogen list. Being a primary cause of persistent human infections, biofilm forming ability of S. aureus plays a pivotal role in the development of antibiotic resistance. Hence, targeting biofilm is an alternative strategy to fight bacterial infections. The present study for the first time demonstrates the non-antibacterial biofilm inhibitory efficacy of 5-Dodecanolide (DD) against ATCC strain and clinical isolates of S. aureus. In addition, DD is able to inhibit adherence of MRSA on human plasma coated Titanium surface. Further, treatment with DD significantly reduced the eDNA synthesis, autoaggregation, staphyloxanthin biosynthesis and ring biofilm formation. Reduction in staphyloxanthin in turn increased the susceptibility of MRSA to healthy human blood and H2O2 exposure. Quantitative PCR analysis revealed the induced expression of agrA and agrC upon DD treatment. This resulted down regulation of genes involved in biofilm formation such as fnbA and fnbB and up regulation of RNAIII, hld, psmα and genes involved in biofilm matrix degradation such as aur and nuc. Inefficacy of DD on the biofilm formation of agr mutant further validated the agr mediated antibiofilm potential of DD. Notably, DD was efficient in reducing the in vivo colonization of MRSA in Caenorhabditis elegans. Results of gene expression studies and physiological assays unveiled the agr mediated antibiofilm efficacy of DD.

scholarly journals Mode of action of Elasnin as biofilm-formation eradicator of Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Author(s):  
Lexin Long ◽  
Jordy Evan Sulaiman ◽  
Yao Xiao ◽  
Aifang Cheng ◽  
Ruojun WANG ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Penicillin G ◽  
Dependent Manner ◽  
Resistance Development ◽  
Methicillin Resistant ◽  
Wide Range ◽  
Increased Sensitivity ◽  
Low Cytotoxicity

Abstract Biofilm is made by microbes and often offers protection by making them more tolerant, resistant, and resilient to wide-range antimicrobials. Biofilm-related infections account for more than 80% of human bacterial infections and are especially prevalent in chronic tissue and device-related infections. Owing to the great challenge in treating biofilms, novel and effective antibiofilm compounds urgently need to be identified. We herein identified elasnin as a potent biofilm-targeting compound against methicillin-resistant Staphylococcus aureus (MRSA) through bioassay-guided isolation of bioactive compounds from Actinobacteria. Elasnin effectively inhibited biofilm formation and eradicated pre-formed biofilms of MRSA, and it displays low cytotoxicity with a low risk of resistance development. Transcriptomic and proteomic analyses combined with confocal microscopy observation revealed that elasnin destroyed the biofilm matrix in a time-dependent manner and interfered with cell cycle during the exponential phase, primarily by repressing the expression of virulence factors. Moreover, the biofilm cells released from elasnin treatment showed increased sensitivity to penicillin G. Overall, this study identified elasnin as a promising biofilm-eradicating compound against MRSA and shed light on its action mechanism.

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.

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