Rapid fluorescence assessment of intracellular pH as a viability indicator of Clavibacter michiganensis subsp. michiganensis

Chitarra, L. G.; Breeuwer, P.; Bulk, R.W. van den; Abee, Tjakko

doi:10.1046/j.1365-2672.2000.01014.x

Cited by 38 publications

(24 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The intracellular pH of A. laidlawii and S. melliferum cells was determined by spectrofluorometry using the internally conjugated fluorescent probe 5(6-)-carboxyfluorescein succinimidyl ester [37] as described previously [33].…”

Section: Determination Of Intracellular Phmentioning

confidence: 99%

The antibiotic activity of cationic linear amphipathic peptides: lessons from the action of leucine/lysine copolymers on bacteria of the class Mollicutes

Béven

Castano

Dufourcq

et al. 2003

European Journal of Biochemistry

View full text Add to dashboard Cite

Peptides composed of leucyl and lysyl residues (ÔLK peptidesÕ) with different compositions and sequences were compared for their antibacterial activities using cell wall-less bacteria of the class Mollicutes (acholeplasmas, mycoplasmas and spiroplasmas) as targets. The antibacterial activity of the amphipathic a-helical peptides varied with their size, 15 residues being the optimal length, independent of the membrane hydrophobic core thickness and the amount of cholesterol. The 15-residue ideally amphipathic a helix with a +5 positive net charge (KLLKLLLKLLLKLLK) had the strongest antibacterial activity, similar to that of melittin. In contrast, scrambled peptides devoid of amphipathy and the less hydrophobic b-sheeted peptides [(LK) n K], even those 15-residue long, were far less potent than the helical ones. Furthermore, the growth inhibitory activity of the peptides was correlated with their ability to abolish membrane potential. These data are fully consistent with a predominantly flat orientation of LK peptides at the lipid/ water interface and strongly supports that these peptides and probably the linear polycationic amphipathic defence peptides act on bacterial membranes in four main steps according to the ÔcarpetÕ model: (a) interfacial partitioning with accumulation of monomers on the target membrane (limiting step); (b) peptide structural changes (conformation, aggregation, and orientation) induced by interactions with the lipid bilayer (as already shown with liposomes and erythrocytes); (c) plasma membrane permeabilization/ depolarization via a detergent-like effect; and (d) rapid bacterial cell death if the extent of depolarization is maintained above a critical threshold.Keywords: amphipathic peptides; antibacterial activity; bacterial cell death; membrane depolarization; mollicutes.The amphipathic a helix concept helps in understanding the behaviour of very different classes of proteins and peptides, especially those acting on membranes [1][2][3][4]. This concept, which has been useful in the field of peptidic cytotoxins to develop new analogues, and to better understand their mode of action [5][6][7], is still the basis for the rational design of new antimicrobial compounds, i.e. analogues or chimeras of natural products [8], or radically new molecules [9,10].The need to understand their mode of action and improve their efficacy and/or selectivity towards microorganisms led to the synthesis of new active peptides, made possible largely by the progress in solid state synthesis. As a result, a large wealth of information was obtained on many natural peptides endowed with cytotoxic (including antimicrobial) activity. However, answers are still missing regarding: (a) the requirements for optimized activity and selectivity; and (b) the mechanisms of action, especially in bacterial cells. In an effort of rationalization, a minimalistic approach was initiated by the pioneering work of De Grado and Lear [11] using residue substitutions or designing simplified sequences [2,[12][13][14]. Using the very mini...

show abstract

Section: Determination Of Intracellular Phmentioning

confidence: 99%

The antibiotic activity of cationic linear amphipathic peptides: lessons from the action of leucine/lysine copolymers on bacteria of the class Mollicutes

Béven

Castano

Dufourcq

et al. 2003

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…Recently, new viability assays were developed for bacteria (Keer and Birch 2003). These tests were essentially based on respiratory activity (Bhupathiraju et al 1999;Rodriguez et al 1992), external membrane integrity (Nebe-von-Caron et al 2000), intracellular pH (Chitara et al 2000), and membrane potential (Deere et al 1995;Manson et al 1993Manson et al , 1994Manson et al , 1995. The major advantage of these new technologies is the rapidity of response and the multi-parametric nature of the collected information.…”

Section: Introductionmentioning

confidence: 99%

Flow cytometry analysis of germinating Bacillus spores, using membrane potential dye

Laflamme

Veillette

et al. 2004

Arch Microbiol

View full text Add to dashboard Cite

“…The capacity of cells to maintain a pH gradient (higher pH inside than outside the cell) may also supply information about cellular viability (9). In principle, these bacterial vital signs (intracellular pH, ATP production, and membrane potential and integrity) could form the basis of a rapid search for novel antimicrobial agents.…”

mentioning

confidence: 99%

Extracts of Edible and Medicinal Plants Damage Membranes of Vibrio cholerae

Sánchez

García

Heredia

2010

Appl Environ Microbiol

225

117

View full text Add to dashboard Cite

The use of natural compounds from plants can provide an alternative approach against food-borne pathogens. The mechanisms of action of most plant extracts with antimicrobial activity have been poorly studied. In this work, changes in membrane integrity, membrane potential, internal pH (pH in ), and ATP synthesis were measured in Vibrio cholerae cells after exposure to extracts of edible and medicinal plants. A preliminary screen of methanolic, ethanolic, and aqueous extracts of medicinal and edible plants was performed. Minimal bactericidal concentrations (MBCs) were measured for extracts showing high antimicrobial activity. Our results indicate that methanolic extracts of basil (Ocimum basilicum L.), nopal cactus (Opuntia ficus-indica var. Villanueva L.), sweet acacia (Acacia farnesiana L.), and white sagebrush (Artemisia ludoviciana Nutt.) are the most active against V. cholera, with MBCs ranging from 0.5 to 3.0 mg/ml. Using four fluorogenic techniques, we studied the membrane integrity of V. cholerae cells after exposure to these four extracts. Extracts from these plants were able to disrupt the cell membranes of V. cholerae cells, causing increased membrane permeability, a clear decrease in cytoplasmic pH, cell membrane hyperpolarization, and a decrease in cellular ATP concentration in all strains tested. These four plant extracts could be studied as future alternatives to control V. cholerae contamination in foods and the diseases associated with this microorganism.

show abstract

Rapid fluorescence assessment of intracellular pH as a viability indicator of Clavibacter michiganensis subsp. michiganensis

Cited by 38 publications

References 12 publications

The antibiotic activity of cationic linear amphipathic peptides: lessons from the action of leucine/lysine copolymers on bacteria of the class Mollicutes

The antibiotic activity of cationic linear amphipathic peptides: lessons from the action of leucine/lysine copolymers on bacteria of the class Mollicutes

Flow cytometry analysis of germinating Bacillus spores, using membrane potential dye

Extracts of Edible and Medicinal Plants Damage Membranes of Vibrio cholerae

Contact Info

Product

Resources

About