Effect ofPseudomonas aeruginosa rhamnolipid on human neutrophil migration

Shryock, Thomas R.; Silver, Scott A.; Banschbach, Martin W.; Kramer, John C.

doi:10.1007/bf01626559

Cited by 30 publications

(17 citation statements)

References 13 publications

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“…Repression of these genes may contribute to the development of the less structured and more antibiotic sensitive biofilm seen in QS mutants. Moreover, rhamnolipid and lectin LecA have been reported to have cytotoxic effects on mammalian cells, including neutrophils and macrophages, and are also important in the P. aeruginosa infectious process (5,45,57,58,81,82,95).…”

Section: Discussionmentioning

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: Discussionmentioning

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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“…Other remarkable properties of RLs as lysis induction of polymorphonuclear leukocytes (PMNs) or antimicrobial activity have also been referred by (Jensen et al 2007;Shryock et al 1984;Van Gennip et al 2009). Concerning their mechanism of action, it consists of intercalation into the biological membrane and destruction by their permeabilizing effect (Sotirova et al 2008).…”

Section: Introductionmentioning

confidence: 98%

On the Thermus thermophilus HB8 potential pathogenicity triggered from rhamnolipids secretion: morphological alterations and cytotoxicity induced on fibroblastic cell line

Pantazaki

Choli‐Papadopoulou

2011

Amino Acids

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A limited number of bacterial strains usually grown under nutrient limitation secrete rhamnolipids (RLs), which are recorded as virulence factors that are implicated in the pathogenicity of a microorganism. The non-pathogenic T. thermophilus HB8 produces extracellular rhamnolipids (TthRLs) under defined cultivation conditions using sunflower seed oil and sodium gluconate as carbon sources. In particular, the secreted TthRLs have been isolated, purified and identified with ATR-FTIR. Their effects on the cells' viability were examined when they were supplemented in a culture of human skin fibroblasts. Purified TthRLs triggered a sequence of rapid and pronounced morphological alterations characterized by transformation of fibroblast shape from polygonal to fusiform; retraction with cytoplasm condensation, rounding up, distortion of nuclei and loss of lamellar processes, and finally disruption of membrane. The addition of TthRLs in the cultured fibroblasts caused cytotoxicity, in contrast to that of rhamnose that stimulated viability, as it was assessed by MTT test. These results revealed that among the constituents of RLs that are implicated in the cytotoxicity, it has to be attributed to the lipidic chain variation and not to the carbohydrate part. TthRLs cytotoxicity on fibroblasts is comparable, and provoked similar effects, to that caused by saponin white, a known surfactant. TthRLs secretion might be a crucial point for the transformation of a non-pathogenic bacterium to a pathogenic one under certain environmental conditions favoring their secretion. RLs secretion in the microorganism's world might be a general route for the passage in the pathogenicity to ensure their survival under nutrient limitation conditions.

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“…These rhamnolipids have been reported to be highly destructive of tracheal epithelial cell cilia ~Itrastructure.~ The structures of the two major rhamnolipids, a-~-rhamnopyranosyl-3-hydroxydecanoyl-3-hydroxydecanoate (RL-1) and a+- associated with the insertion of the two apolar fatty acid residues into the phospholipid bilayer of cell membrane^.^ The rhamnolipids are thought to facilitate competitive pseudomonad growth in adverse environments since they are bactericidal, mycoplasrnacidal and a n t i~i r a l ,~ and probably play a role in the pathogenesis of chronic lung infection. 6 Recently, the rhamnolipids have been shown to be potent mucus secretagogues both on feline trachea in uiuo and human bronchial mucosa in uitro. ' Syldatk et aL8 reported NMR assignments for the rhamnolipids dissolved in CDCl, using 1D NMR spectroscopy.…”

Section: Introduction Prolonged Colonization Of the Lungs Bymentioning

confidence: 99%