Antimicrobial activity of various cationic molecules on foodborne pathogens

Conte, Mariachiara; Aliberti, Francesco; Fucci, Laura; Piscopo, Marina

doi:10.1007/s11274-007-9415-6

Cited by 36 publications

(31 citation statements)

References 19 publications

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“…S1 in the supplemental material) were employed for the phenotyping of the ⌬Pa comp , ⌬Sa comp , and ⌬Bs comp complemented strains. For these types of molecules, interaction with the bacterial membrane was described as a mode of antibacterial action in Gram-positive organisms (4,9,18,38,48,53). However, in the present investigation, no complementation of the Gramnegative model organism P. aeruginosa was observed in the presence of protamine sulfate, poly-L-lysine, and polymyxin E. These findings clearly differ from the results of related complementation experiments employing Gram-positive model organisms (59,65).…”

Section: Resultscontrasting

confidence: 94%

Resistance Phenotypes Mediated by Aminoacyl-Phosphatidylglycerol Synthases

et al. 2012

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The specific aminoacylation of the phospholipid phosphatidylglycerol (PG) with alanine or with lysine catalyzed by aminoacylphosphatidylglycerol synthases (aaPGS) was shown to render various organisms less susceptible to antibacterial agents. This study makes use of Pseudomonas aeruginosa chimeric mutant strains producing lysyl-phosphatidylglycerol (L-PG) instead of the naturally occurring alanyl-phosphatidylglycerol (A-PG) to study the resulting impact on bacterial resistance. Consequences of such artificial phospholipid composition were studied in the presence of an overall of seven antimicrobials (␤-lactams, a lipopeptide antibiotic, cationic antimicrobial peptides [CAMPs]) to quantitatively assess the effect of A-PG substitution (with L-PG, L-PG and A-PG, increased A-PG levels). For the employed Gram-negative P. aeruginosa model system, an exclusive charge repulsion mechanism does not explain the attenuated antimicrobial susceptibility due to PG modification. Additionally, the specificity of nine orthologous aaPGS enzymes was experimentally determined. The newly characterized protein sequences allowed for the establishment of a significant group of A-PG synthase sequences which were bioinformatically compared to the related group of L-PG synthesizing enzymes. The analysis revealed a diverse origin for the evolution of A-PG and L-PG synthases, as the specificity of an individual enzyme is not reflected in terms of a characteristic sequence motif. This finding is relevant for future development of potential aaPGS inhibitors.

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Section: Resultscontrasting

confidence: 94%

Resistance Phenotypes Mediated by Aminoacyl-Phosphatidylglycerol Synthases

et al. 2012

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“…Because of their high density of charge, the lipid to peptide ratios at which this phenomenon occurs are much higher than those with small peptides. PLL and PLA have been shown to have antimicrobial activity (32). K and R are common charged residues found in antimicrobial peptides, unlike O or Dab.…”

Section: Resultsmentioning

confidence: 99%

Probing the “Charge Cluster Mechanism” in Amphipathic Helical Cationic Antimicrobial Peptides

2010

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Clustering of anionic lipids away from zwitterionic ones by cationic antimicrobial agents has recently been established as a mechanism of action of natural small, flexible peptides as well as non-natural synthetic peptide mimics. One of the largest classes of antimicrobial peptides are those that form cationic amphipathic helices on membranes and whose toxic action is dependent on the formation of pores in the membrane or through the "carpet" mechanism. We have evaluated the role of anionic lipid clustering for five of these peptides, i.e., MSI-78, MSI-103, MSI-469, MSI-843 and MSI-1254, with different sequences and properties. We determined whether these amphipathic helical cationic antimicrobial peptides cluster anionic lipids from zwitterionic ones and if this property is related to the species specificity of their toxicity. All five of these peptides were capable of lipid clustering, in contrast to the well studied amphipathic helical antimicrobial peptide, magainin 2, which does not. We ascribe this difference to the lower density of positive charges in magainin 2. Peptides which efficiently cluster anionic lipids generally have a ratio of MIC for S. aureus to that for E. coli >1. The addition of an N-terminal octyl chain did not preclude anionic charge clustering, although the ratio of MIC for S. aureus to that for E. coli was somewhat lowered. In most Gram positive bacteria there is a predominance of anionic lipids in the cytoplasmic membrane. In Gram negative bacteria, however, clustering of anionic lipids away from zwitterionic ones is emerging as an important contributing mechanism of bacterial toxicity for some antimicrobial agents.There is much current interest in increasing the therapeutic efficacy of antimicrobial peptides (1-3). A large variety of antimicrobial agents have been designed for this purpose (4) and one of the major groups comprises the cationic, linear peptides that can form amphipathic helices in a membrane environment, the Amphipathic Helical Cationic Antimicrobial Peptides (AHCAPs). Some of these antimicrobial peptides are also of interest because of their anticancer activities (5). This study deals with five different AHCAPs, whose sequences and overall charge at neutral pH are given in Table 1. Some AHCAPs have been shown to damage bacterial membranes by forming pores that can lead to membrane depolarization and even the loss of soluble molecules from the cytoplasm of the cell. A well studied example of a peptide working by this mechanism is provided by magainin 2 (6). Among the peptides used in the current study, MSI-78, an analog of magainin 2, has also been suggested to act by forming a toroidal type pore (7) the location of the peptide in a bilayer (8). It is thus common for amphipathic helical peptides to form pores in membranes. The formation of these pores is coupled with the self-association of many of these peptides in a highly cooperative manner (9) resulting in a high local density of positive charges that could cluster anionic lipids. The phenomenon of cluste...

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“…Mortality rate and percentage of malformations in Xenopus laevis tadpoles exposed to PEI alone (left) and DNA (4:1) polyplexes (right). been stated previously that cationic anti-microbial peptides and dimethylaminoethyl methacrylate (DMAEMA) derived ammonium salts might lead to membrane permeabilization, cell wall and division effects and macromolecular synthesis inhibition (Conte et al, 2007;Lu et al, 2007), a similar effect as for the antibiotic polymixin.…”

Section: Bioreporter Test: Gene Expression Profiling With Bacterial Cmentioning

confidence: 95%