Hemolytic effect of a glycolipid produced byPseudomonas aeruginosa

Sierra, Gonzalo

doi:10.1007/bf02539004

Cited by 34 publications

(15 citation statements)

References 4 publications

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“…We investigated the effects of AZM, CPR, and CFT on the production of heat-stable hemolysin. P. aeruginosa produces at least two hemolysins, the heat-labile phospholipase C (phlC, PA0844) and the heat-stable rhamnolipid (rhlA, rhlB, rhlC, and rhlG; PA3479, PA3478, PA1130, and PA3387, respectively) (9,46,83). Rhamnolipid synthesis is turned on in early stationary phase of P. aeruginosa PAO1 cultures (62,89).…”

Section: Resultsmentioning

confidence: 99%

Effects of Antibiotics on Quorum Sensing in Pseudomonas aeruginosa

Skindersoe

Alhede

Phipps

et al. 2008

Antimicrob Agents Chemother

321

266

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During infection, Pseudomonas aeruginosa employs bacterial communication (quorum sensing [QS]) to coordinate the expression of tissue-damaging factors. QS-controlled gene expression plays a pivotal role in the virulence of P. aeruginosa, and QS-deficient mutants cause less severe infections in animal infection models. Treatment of cystic fibrosis (CF) patients chronically infected with P. aeruginosa with the macrolide antibiotic azithromycin (AZM) has been demonstrated to improve the clinical outcome. Several studies indicate that AZM may accomplish its beneficial action in CF patients by impeding QS, thereby reducing the pathogenicity of P. aeruginosa. This led us to investigate whether QS inhibition is a common feature of antibiotics. We present the results of a screening of 12 antibiotics for their QS-inhibitory activities using a previously described QS inhibitor selector 1 strain. Three of the antibiotics tested, AZM, ceftazidime (CFT), and ciprofloxacin (CPR), were very active in the assay and were further examined for their effects on QS-regulated virulence factor production in P. aeruginosa. The effects of the three antibiotics administered at subinhibitory concentrations were investigated by use of DNA microarrays. Consistent results from the virulence factor assays, reverse transcription-PCR, and the DNA microarrays support the finding that AZM, CFT, and CPR decrease the expression of a range of QS-regulated virulence factors. The data suggest that the underlying mechanism may be mediated by changes in membrane permeability, thereby influencing the flux of N-3-oxo-dodecanoyl-Lhomoserine lactone.

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Section: Resultsmentioning

confidence: 99%

Effects of Antibiotics on Quorum Sensing in Pseudomonas aeruginosa

Skindersoe

Alhede

Phipps

et al. 2008

Antimicrob Agents Chemother

321

266

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“…P. aeruginosa had been known for a long time to produce a solvent-soluble glycolipid with hemolytic activity when, a few years after RLs were reported, the coincidence between the two was noticed (Sierra 1960). Nevertheless, the heat-stable extracellular hemolysin designation for RLs has persisted for many years (Fujita et al 1988; Johnson and Boese-Marrazzo 1980; Kurioka and Liu 1967; Stutts et al 1986).…”

Section: Introductionmentioning

confidence: 99%

Rhamnolipids: diversity of structures, microbial origins and roles

Abdel-Mawgoud

Lépine

Déziel

2010

Appl Microbiol Biotechnol

769

553

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Rhamnolipids are glycolipidic biosurfactants produced by various bacterial species. They were initially found as exoproducts of the opportunistic pathogen Pseudomonas aeruginosa and described as a mixture of four congeners: α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-Rha-C10-C10), α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoate (Rha-Rha-C10), as well as their mono-rhamnolipid congeners Rha-C10-C10 and Rha-C10. The development of more sensitive analytical techniques has lead to the further discovery of a wide diversity of rhamnolipid congeners and homologues (about 60) that are produced at different concentrations by various Pseudomonas species and by bacteria belonging to other families, classes, or even phyla. For example, various Burkholderia species have been shown to produce rhamnolipids that have longer alkyl chains than those produced by P. aeruginosa. In P. aeruginosa, three genes, carried on two distinct operons, code for the enzymes responsible for the final steps of rhamnolipid synthesis: one operon carries the rhlAB genes and the other rhlC. Genes highly similar to rhlA, rhlB, and rhlC have also been found in various Burkholderia species but grouped within one putative operon, and they have been shown to be required for rhamnolipid production as well. The exact physiological function of these secondary metabolites is still unclear. Most identified activities are derived from the surface activity, wetting ability, detergency, and other amphipathic-related properties of these molecules. Indeed, rhamnolipids promote the uptake and biodegradation of poorly soluble substrates, act as immune modulators and virulence factors, have antimicrobial activities, and are involved in surface motility and in bacterial biofilm development.

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“…This pathogen is the causative agent of melioidosis, an infectious disease endemic to Southeast Asia, northern Australia and tropical and subtropical regions (Andrea et al 2008 ). The di-rhamnolipids from B. pseudomallei have been found to exhibit serious cytotoxic effects on macrophages non-phagocytic and phagocytic cell lines (Sierra 1960 ;Kharazmi et al 1989 ;Johnson and Boese-Marrazzo 1980 ;Fujita et al 1988 ). Di-rhamnolipids have also been reported to be cytolytic to human monocyte-derived macrophages and can inhibit the phagocytic response of macrophages even at low concentration.…”

Section: Rhamnolipidsmentioning

confidence: 95%

Production of Biosurfactants Using Eco-friendly Microorganisms

Uzoigwe

Ennis

Rahman

2014

Environmental Sustainability

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Pathogenicity of biosurfactant-producing microorganisms is currently raising some health, safety and environmental concerns. As a result, the industrial-scale production and application of biosurfactants as potential alternatives to the synthetic one is still an unachieved task. The production of biosurfactants using nonpathogenic/recombinant strains requires more attention and investigation for some advantages that includes the discovery of non-toxic biosurfactants suitable for all industrial applications, identifying new biosurfactant congeners with better inherent surfaceactive properties compared to that from pathogens and synthetic ones and the synthesis of biosurfactant without complex metabolic regulations. Although a number of nonpathogenic/recombinant, eco-friendly biosurfactant-producing strains have been documented, there is need for more research in this area focusing especially on improved biosurfactant production by these strains using optimisation processes and the discovery of new nonpathogenic/recombinant strains using molecular techniques for future sustainability.

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Hemolytic effect of a glycolipid produced byPseudomonas aeruginosa

Cited by 34 publications

References 4 publications

Effects of Antibiotics on Quorum Sensing in Pseudomonas aeruginosa

Effects of Antibiotics on Quorum Sensing in Pseudomonas aeruginosa

Rhamnolipids: diversity of structures, microbial origins and roles

Production of Biosurfactants Using Eco-friendly Microorganisms

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