The role of reactive oxygen species in the antimicrobial activity of pyochelin

Ong, Kuan Shion; Cheow, Yuen Lin; Lee, Sui Mae

doi:10.1016/j.jare.2017.05.007

Cited by 105 publications

(52 citation statements)

References 33 publications

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“…5a) and lipid peroxidation (Fig. 3b) confirmed significant macromolecular damage, which is in accordance with previous reports of macromolecular damage due to extensive ROS production in bacterial cells [38,39]. Thus, it can be suggested that due to extensive macromolecular damage the E. coli cells are drifted towards cellular death as evident from colony forming data (Fig.…”

Section: Discussionsupporting

confidence: 91%

ROS mediated antibacterial activity of photoilluminated riboflavin: A photodynamic mechanism against nosocomial infections

Khan

Rizvi

et al. 2019

Toxicology Reports

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Section: Discussionsupporting

confidence: 91%

ROS mediated antibacterial activity of photoilluminated riboflavin: A photodynamic mechanism against nosocomial infections

Khan

Rizvi

et al. 2019

Toxicology Reports

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“…An early report on P. aeruginosa PAO1 mutants carrying different point mutations in the fur gene highlighted that cells expressing defective variants of Fur were more sensitive to oxidative stress (38), in agreement with the indirect role of Fur as a positive regulator of important ROS-detoxifying enzymes, such as the catalase KatA and the superoxide dismutase SodB (39). Moreover, it has recently been demonstrated that pyochelin can act as an antibiotic against some bacterial species by inducing the generation of ROS (40,41). The growth-inhibitory effect of pyochelin is not related to its iron-chelating (siderophore) activity and is suppressed by ROS-scavenging compounds such as catecholate siderophores (e.g., enterobactin) and ascorbic acid (40).…”

Section: Figmentioning

confidence: 71%

Ferric Uptake Regulator Fur Is Conditionally Essential in Pseudomonas aeruginosa

et al. 2017

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In , the ferric uptake regulator (Fur) protein controls both metabolism and virulence in response to iron availability. Differently from other bacteria, attempts to obtain deletion mutants of failed, leading to the assumption that Fur is an essential protein in this bacterium. By investigating a conditional mutant, we demonstrate that Fur is not essential for growth in liquid media, biofilm formation, and pathogenicity in an insect model of infection. Conversely, Fur is essential for growth on solid media since Fur-depleted cells are severely impaired in colony formation. Transposon-mediated random mutagenesis experiments identified pyochelin siderophore biosynthesis as a major cause of the colony growth defect of the conditional mutant, and deletion mutagenesis confirmed this evidence. Impaired colony growth of pyochelin-proficient Fur-depleted cells does not depend on oxidative stress, since Fur-depleted cells do not accumulate higher levels of reactive oxygen species (ROS) and are not rescued by antioxidant agents or overexpression of ROS-detoxifying enzymes. Ectopic expression of genes revealed that pyochelin production has no inhibitory effects on a deletion mutant of pv. , suggesting that the toxicity of the locus in Fur-depleted cells involves a -specific pathway(s). Members of the ferric uptake regulator (Fur) protein family are bacterial transcriptional repressors that control iron uptake and storage in response to iron availability, thereby playing a crucial role in the maintenance of iron homeostasis. While null mutants of many bacteria have been obtained, Fur appears to be essential in for still unknown reasons. We obtained Fur-depleted cells by conditional mutagenesis and showed that Fur is dispensable for planktonic growth, while it is required for colony formation. This is because Fur protects colonies from toxicity exerted by the pyochelin siderophore. This work provides a functional basis to the essentiality of Fur in and highlights unique properties of the Fur regulon in this species.

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“…The background fluorescence of 0.85% saline and autofluorescence of the bacterial cells incubated without the probe was measured to calculate the net fluorescence emitted from the assay itself. The experiment was conducted in triplicate [ 60 ].…”

Section: Methodsmentioning

confidence: 99%

Prenylated Flavonoids with Potential Antimicrobial Activity: Synthesis, Biological Activity, and In Silico Study

Osorio

Carvajal

Vergara

et al. 2021

IJMS

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Prenylated flavonoids are an important class of naturally occurring flavonoids with important biological activity, but their low abundance in nature limits their application in medicines. Here, we showed the hemisynthesis and the determination of various biological activities of seven prenylated flavonoids, named 7–13, with an emphasis on antimicrobial ones. Compounds 9, 11, and 12 showed inhibitory activity against human pathogenic fungi. Compounds 11, 12 (flavanones) and 13 (isoflavone) were the most active against clinical isolated Staphylococcus aureus MRSA, showing that structural requirements as prenylation at position C-6 or C-8 and OH at positions C-5, 7, and 4′ are key to the antibacterial activity. The combination of 11 or 12 with commercial antibiotics synergistically enhanced the antibacterial activity of vancomycin, ciprofloxacin, and methicillin in a factor of 10 to 100 times against drug-resistant bacteria. Compound 11 combined with ciprofloxacin was able to decrease the levels of ROS generated by ciprofloxacin. According to docking results of S enantiomer of 11 with ATP-binding cassette transporter showed the most favorable binding energy; however, more studies are needed to support this result.

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The role of reactive oxygen species in the antimicrobial activity of pyochelin

Abstract: Graphical abstract

Cited by 105 publications

References 33 publications

ROS mediated antibacterial activity of photoilluminated riboflavin: A photodynamic mechanism against nosocomial infections

ROS mediated antibacterial activity of photoilluminated riboflavin: A photodynamic mechanism against nosocomial infections

Ferric Uptake Regulator Fur Is Conditionally Essential in Pseudomonas aeruginosa

Prenylated Flavonoids with Potential Antimicrobial Activity: Synthesis, Biological Activity, and In Silico Study

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