scholarly journals Assessment of the anti-virulence potential of extracts from four plants used in traditional Chinese medicine against multidrug-resistant pathogens

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zhonghui Pu ◽  
Huaqiao Tang ◽  
Nana Long ◽  
Min Qiu ◽  
Mingxiang Gao ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Chinese Medicine ◽  
Biofilm Formation ◽  
Ethanol Extract ◽  
Quorum Quenching ◽  
Toxin Production ◽  
Multidrug Resistant ◽  
Virulence Potential ◽  
Low Concentrations ◽  
Multidrug Resistant Pathogens

Abstract Background Multidrug-resistant pathogens are resistant to many antibiotics and associated with serious infections. Amomum tsaoko Crevost et Lemaire, Sanguisorba officinalis, Terminalia chebula Retz and Salvia miltiorrhiza Bge, are all used in Traditional Chinese Medicine (TCM) against multidrug-resistant pathogens, and the purpose of this study was to evaluate the antibacterial and anti-virulence activity of extracts derived from them. Methods The antibacterial activity of ethanol and aqueous extracts from these four plants was examined against several multi-drug resistant bacterial strains, and their anti-virulence potential (including quorum quenching activity, biofilm inhibition, and blocking production of virulence factor δ-toxin) was assessed against different S. aureus strains. The chemical composition of the most effective extract was determined by LC-FTMS. Results Only extracts from S. officinalis and A. tsaoko were shown to exhibit limited growth inhibition activity at a dose of 256 μg·mL-1. The S. officinalis ethanol extract, the ethanol and aqueous extract of A. tsaoko, and the aqueous extract of S. miltiorrhiza all demonstrated quorum quenching activity, but didn’t significantly inhibit bacterial growth. The ethanol extract of S. officinalis inhibited bacterial toxin production and biofilm formation at low concentrations. Chemical composition analysis of the most effective extract of S. officinalis showed that it mainly contained saponins. Conclusions The most active extract tested in this study was the ethanol root extract of S. officinalis. It inhibited δ-toxin production and biofilm formation at low concentrations and saponins may be its key active components. While the four plants showed no direct antibacterial effects, their anti-virulence properties may be key to fighting bacterial infections.

Based Natural Products as Quorum Sensing Inhibitors in E. Coli: A Critical Review

2021 ◽  
Vol 21 ◽  
Author(s):  
A.P. Cardiliya ◽  
A. Selvaraj ◽  
M.J. Nanjan ◽  
M.J.N. Chandrasekar
Keyword(s):  
Natural Products ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Present Report ◽  
Resistance Mechanism ◽  
Multidrug Resistant ◽  
Bacterial Diseases ◽  
E Coli ◽  
Pharmaceutical Industries ◽  
Multidrug Resistant Pathogens

: The existence of multidrug–resistant (MDR) E .coli (superbugs) is a global health issue confronting humans, livestock, food processing units, and pharmaceutical industries. The quorum sensing (QS) controlling ability of the E .coli to form biofilms has become one of the important reasons for the emergence of multidrug-resistant pathogens. Quorum signaling activation and formation of biofilm lead to the emergence of antimicrobial resistance of the pathogens increasing the therapy difficulty for treating bacterial diseases. There is a crucial need, therefore, to reinforce newer therapeutic designs to overcome this resistance. As the infections caused by E .coli are attributed via the QS-regulated biofilm formation, easing this system by QS inhibitors is a possible strategy for treating bacterial diseases. Plant based natural products have been reported to bind to QS receptors and interrupt the QS systems of pathogens by inhibiting biofilm formation and disrupting the formed biofilms, thus minimizing the chances to develop a resistance mechanism. The present report reviews critically the QS capability of E .coli to form biofilms leading to multidrug resistant pathogens and the investigations that have been carried out so far on plant acquired natural products as QS inhibitors.

scholarly journals Effects of colistin and tigecycline on multidrug-resistant Acinetobacter baumannii biofilms: advantages and disadvantages of their combination

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshinori Sato ◽  
Tsuneyuki Ubagai ◽  
Shigeru Tansho-Nagakawa ◽  
Yusuke Yoshino ◽  
Yasuo Ono
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Combined Effects ◽  
Inhibitory Effects ◽  
Advantages And Disadvantages ◽  
Low Concentrations ◽  
Bactericidal Effects ◽  
Complete Disruption ◽  
High Concentrations

AbstractWe investigated the antimicrobial effects of colistin (CST) and tigecycline (TGC), either alone or in combination, on biofilm-dispersed and biofilm-embedded multidrug-resistant Acinetobacter baumannii (MDRAB) strains R1 and R2. The bacterial growth of biofilm-dispersed MDRAB was inhibited by CST or TGC. However, the inhibitory effects were attenuated by a combination of CST and low concentrations of TGC. The bactericidal effects of CST, but not TGC, were observed on biofilm-dispersed MDRAB. Notably, the bactericidal effects increased with a combination of CST and high concentrations of TGC, whereas they were attenuated with the combination of CST and low concentrations of TGC. Although biofilm formation by MDRAB decreased with increasing concentrations of CST or TGC, there was no complete disruption of the biofilms. Additionally, the biofilms increased with a combination of 1–2 μg/mL CST and TGC at 2 μg/mL and 2–4 μg/mL for strains R1 and R2, respectively. Biofilm-embedded MDRAB was eradicated with CST, but not TGC. Notably, the eradication effects increased with a combination of CST and high concentrations of TGC, whereas attenuation happened with the combination of CST and low concentrations of TGC. These results provide information on the combined effects of CST and TGC in the treatment of biofilm-associated MDRAB infection.

scholarly journals Disruption of Biofilm Formation by the Human Pathogen Acinetobacter baumannii Using Engineered Quorum-Quenching Lactonases

2013 ◽  
Vol 58 (3) ◽  
pp. 1802-1805 ◽  
Author(s):  
Jeng Yeong Chow ◽  
Yuanyong Yang ◽  
Song Buck Tay ◽  
Kim Lee Chua ◽  
Wen Shan Yew
Keyword(s):  
Quorum Sensing ◽  
Acinetobacter Baumannii ◽  
Directed Evolution ◽  
Nosocomial Infections ◽  
Biofilm Formation ◽  
Quorum Quenching ◽  
Multidrug Resistant ◽  
Human Pathogen ◽  
Content Type ◽  
Biofilm Disruption

ABSTRACTAcinetobacter baumanniiis a major human pathogen associated with multidrug-resistant nosocomial infections; its virulence is attributed to quorum-sensing-mediated biofilm formation, and disruption of biofilm formation is an attractive antivirulence strategy. Here, we report the first successful demonstration of biofilm disruption in a clinical isolate ofA. baumanniiS1, using a quorum-quenching lactonase obtained by directed evolution; this engineered lactonase significantly reduced the biomass ofA. baumannii-associated biofilms, demonstrating the utility of this antivirulence strategy.

scholarly journals Comparative Antimicrobial Activity of Hp404 Peptide and Its Analogs against Acinetobacter baumannii

2021 ◽  
Vol 22 (11) ◽  
pp. 5540
Author(s):  
Min Ji Hong ◽  
Min Kyung Kim ◽  
Yoonkyung Park
Keyword(s):  
Antimicrobial Activity ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Helical Structure ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Low Concentrations ◽  
Helical Peptide ◽  
Cytoplasmic Membranes

An amphipathic α-helical peptide, Hp1404, was isolated from the venomous gland of the scorpion Heterometrus petersii. Hp1404 exhibits antimicrobial activity against methicillin-resistant Staphylococcus aureus but is cytotoxic. In this study, we designed antimicrobial peptides by substituting amino acids at the 14 C-terminal residues of Hp1404 to reduce toxicity and improve antibacterial activity. The analog peptides, which had an amphipathic α-helical structure, were active against gram-positive and gram-negative bacteria, particularly multidrug-resistant Acinetobacter baumannii, and showed lower cytotoxicity than Hp1404. N-phenyl-1-naphthylamine uptake and DisC3-5 assays demonstrated that the peptides kill bacteria by effectively permeating the outer and cytoplasmic membranes. Additionally, the analog peptides inhibited biofilm formation largely than Hp1404 at low concentrations. These results suggest that the analog peptides of Hp1404 can be used as therapeutic agents against A. baumannii infection.

GC-MS, HPLC, TLC of Dorycnium herbaceum Tincture Species and Synergistic / Antagonist Effect Testing in Combination with Antibiotics

2017 ◽  
Vol 68 (2) ◽  
pp. 228-231 ◽  
Author(s):  
Renata Maria Varut ◽  
Luciana Teodora Rotaru
Keyword(s):  
Chemical Composition ◽  
Clavulanic Acid ◽  
Carboxylic Acids ◽  
Therapeutic Effect ◽  
Antagonistic Effect ◽  
Hydroalcoholic Extract ◽  
Low Concentrations ◽  
Amoxicillin Clavulanic Acid ◽  
Reference Strains ◽  
Antagonist Effect

The study objectives were to determine the chemical composition and the synergistic / antagonistic effect of the association between hydroalcoholic extract from the Dorycnii pentaphylli herba (DPH) and the antibiotics of choice, on five reference strains. The tincture contains flavonoids and polyphenol carboxylic acids in low concentrations. DPH has an antagonistic effect on three of the drugs tested (amoxicillin + clavulanic acid, levofloxacin, amikacin), the therapeutic effect being completely canceled and has no significant effect on two of them (ceftazidime, cefotaxime).

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

scholarly journals Extract from phyllosphere bacteria with antibiofilm and quorum quenching activity to control several fish pathogenic bacteria

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Olivia Nathalia ◽  
Diana Elizabeth Waturangi
Keyword(s):  
Streptococcus Agalactiae ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Vibrio Harveyi ◽  
Quorum Quenching ◽  
Indicator Bacteria ◽  
Antibiofilm Activity ◽  
Fish Pathogen ◽  
Phyllosphere Bacteria

Abstract Objective The objective of this research were to screen quorum quenching activity compound from phyllosphere bacteria as well as antibiofilm activity against several fish pathogen bacteria such as Aeromonas hydrophila, Streptococcus agalactiae, and Vibrio harveyi. Results We found eight phyllosphere bacteria isolates with potential quorum quenching activity to inhibit Chromobacterium violaceum as indicator bacteria. Crude extracts (20 mg/mL) showed various antibiofilm activity against fish pathogenic bacteria used in this study. Isolate JB 17B showed the highest activity to inhibit biofilm formation of A. hydrophila and V. harveyi, meanwhile isolate JB 3B showed the highest activity to inhibit biofilm of S. agalactiae. From destruction assay, isolate JB 8F showed the highest activity to disrupt biofilm of A. hydrophila isolate JB 20B showed the highest activity to disrupt biofilm of V. harveyi, isolate JB 17B also showed the highest activity to disrupt biofilm of S. agalactiae.

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