Leakage of periplasmic proteins from Escherichia coli mediated by polymyxin B nonapeptide

Dixon, Ronald; Chopra, Ian

doi:10.1128/aac.29.5.781

Cited by 96 publications

(83 citation statements)

References 49 publications

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“…Because of an electrostatic interaction occurring between the ␣,␥-diaminobutyric acid (Dab) residue of the positively charged polymyxin on one side and the phosphate groups of the negatively charged lipid A membrane on the other side, divalent cations (Ca 2ϩ and Mg 2ϩ ) are displaced from the negatively charged phosphate groups of membrane lipids (12). The lipopolysaccharide (LPS) is therefore destabilized, consequently increasing the permeability of the bacterial membrane, leading to leakage of the cytoplasmic content and ultimately causing cell death (4,13).…”

Section: Mechanism Of Actionmentioning

confidence: 99%

Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes

2017

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SUMMARY Polymyxins are well-established antibiotics that have recently regained significant interest as a consequence of the increasing incidence of infections due to multidrug-resistant Gram-negative bacteria. Colistin and polymyxin B are being seriously reconsidered as last-resort antibiotics in many areas where multidrug resistance is observed in clinical medicine. In parallel, the heavy use of polymyxins in veterinary medicine is currently being reconsidered due to increased reports of polymyxin-resistant bacteria. Susceptibility testing is challenging with polymyxins, and currently available techniques are presented here. Genotypic and phenotypic methods that provide relevant information for diagnostic laboratories are presented. This review also presents recent works in relation to recently identified mechanisms of polymyxin resistance, including chromosomally encoded resistance traits as well as the recently identified plasmid-encoded polymyxin resistance determinant MCR-1. Epidemiological features summarizing the current knowledge in that field are presented.

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Section: Mechanism Of Actionmentioning

confidence: 99%

Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes

2017

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“…This structure may help paenibacterin to disrupt the cytoplasmic membrane of target cells. Disruption of the cytoplasmic membrane and leakage of cell components are considered the mechanism of action of many cationic antimicrobial peptides, such as polymyxin, octapeptin, and magainin (9,11,35,42). Polymyxin, which is produced by Paenibacillus polymyxa strains, contains six diaminobutyric acids and has five net positive charges (12).…”

Section: Fig 7 1dmentioning

confidence: 99%

Isolation of a Paenibacillus sp. Strain and Structural Elucidation of Its Broad-Spectrum Lipopeptide Antibiotic

Guo

Huang

Yuan

et al. 2012

Appl Environ Microbiol

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ABSTRACTThis research was initiated to search for novel antimicrobial compounds produced by food or environmental microorganisms. A new bacterial strain, designated OSY-SE, which produces a unique and potent antimicrobial agent was isolated from soil. The isolate was identified as aPaenibacillussp. through cultural, biochemical, and genetic analyses. An antimicrobial compound was extracted fromPaenibacillusOSY-SE with acetonitrile and purified using liquid chromatography. After analyses by mass spectrometry (MS) and nuclear magnetic resonance (NMR), the antimicrobial compound was determined to be a cyclic lipopeptide consisting of a C15fatty acyl (FA) chain and 13 amino acids. The deduced sequence is FA-Orn-Val-Thr-Orn-Ser-Val-Lys-Ser-Ile-Pro-Val-Lys-Ile. The carboxyl-terminal Ile is connected to Thr by ester linkage. The new compound, designated paenibacterin, showed antagonistic activities against most Gram-positive and Gram-negative bacteria tested, includingListeria monocytogenes, methicillin-resistantStaphylococcus aureus,Escherichia coliO157:H7, andSalmonella entericaserovar Typhimurium. Paenibacterin is resistant to trypsin, lipase, α-glucosidase, and lysozyme. Its antimicrobial activity was lost after digestion by pronase and polymyxin acylase. Paenibacterin is readily soluble in water and fairly stable to exposure to heat and a wide range of pH values. The new isolate and its antimicrobial agent are being investigated for usefulness in food and medical applications.

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“…As the initial site of action, the polycationic polymyxin molecules displace Mg 2ϩ and Ca 2ϩ ions that cross-bridge between adjacent negatively charged phosphate groups of lipopolysaccharides (LPS) in the outer membrane of Gram-negative bacteria (19,33,39,48,61). High concentrations of Mg 2ϩ and Ca 2ϩ can competitively inhibit the effects of polymyxins (48,55,56).…”

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confidence: 99%

Attenuation of Colistin Bactericidal Activity by High Inoculum of Pseudomonas aeruginosa Characterized by a New Mechanism-Based Population Pharmacodynamic Model

Bulitta

Yang

Yohonn

et al. 2010

Antimicrob Agents Chemother

119

130

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Colistin is increasingly being utilized against Gram-negative pathogens, including Pseudomonas aeruginosa, resistant to all other antibiotics. Since limited data exist regarding killing by colistin at different initial inocula (CFUo), we evaluated killing of Pseudomonas aeruginosa by colistin at several CFUo and developed a mechanism-based mathematical model accommodating a range of CFUo. In vitro time-kill experiments were performed using >8 concentrations up to 64 ؋ the MIC of colistin against P. aeruginosa PAO1 and two clinical P. aeruginosa isolates at CFUo of 10 6 , 10 8 , and 10 9 CFU/ml. Serial samples up to 24 h were simultaneously modeled in the NONMEM VI (results shown) and S-ADAPT software programs. The mathematical model was prospectively "validated" by additional time-kill studies assessing the effect of Ca 2؉ and Mg 2؉ on killing of PAO1 by colistin. Against PAO1, killing of the susceptible population was 23-fold slower at the 10 9 CFUo and 6-fold slower at the 10 8 CFUo than at the 10 6 CFUo. The model comprised three populations with different second-order killing rate constants (5.72, 0.369, and 0.00210 liters/h/mg). Bacteria were assumed to release signal molecules stimulating a phenotypic change that inhibits killing. The proposed mechanism-based model had a good predictive performance, could describe killing by colistin for all three studied strains and for two literature studies, and performed well in a prospective validation with various concentrations of Ca 2؉ and Mg 2؉ . The extent and rate of killing of P. aeruginosa by colistin were markedly decreased at high CFUo compared to those at low CFUo. This was well described by a mechanism-based mathematical model, which should be further validated using dynamic in vitro models.

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Leakage of periplasmic proteins from Escherichia coli mediated by polymyxin B nonapeptide

Cited by 96 publications

References 49 publications

Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes

Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes

Isolation of a Paenibacillus sp. Strain and Structural Elucidation of Its Broad-Spectrum Lipopeptide Antibiotic

Attenuation of Colistin Bactericidal Activity by High Inoculum of Pseudomonas aeruginosa Characterized by a New Mechanism-Based Population Pharmacodynamic Model

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