Growth of Salmonella Enteritidis in the presence of quorum sensing signaling compounds produced by Pseudomonas aeruginosa

Abstract Quorum sensing (QS) can exist in food-related bacteria and potentially affect bacterial growth through acyl-homoserine lactones (AHLs). To verify the role of QS compounds in the cell-free supernatant, this study examined the effect of supernatant extracted from Pseudomonas aeruginosa culture on the growth kinetics of Salmonella Enteritidis. The results showed that the lag time (λ) of S. Enteritidis was apparently reduced (p < 0.05) under the influence of P. aeruginosa culture supernatant compared with the S. Enteritidis culture supernatant. HPLC-MS/MS test demonstrated that AHLs secreted by P. aeruginosa were mainly C14-HSL with a content of 85.71 μg/mL and a small amount of 3-oxo-C12-HSL. In addition, the commercially synthetic C14-HSL had positive effects on the growth of S. Enteritidis, confirming once again that the growth of S. Enteritidis was affected by AHL metabolized by other bacteria and the complexity of bacterial communication.

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Biosynthetic Pathway of Pseudomonas aeruginosa 4-Hydroxy-2-Alkylquinolines

Journal of Bacteriology ◽

10.1128/jb.187.11.3630-3635.2005 ◽

2005 ◽

Vol 187 (11) ◽

pp. 3630-3635 ◽

Cited By ~ 92

Author(s):

Florian Bredenbruch ◽

Manfred Nimtz ◽

Victor Wray ◽

Michael Morr ◽

Rolf Müller ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Biosynthetic Pathway ◽

Gas Chromatography Mass Spectrometry ◽

Signal Molecules ◽

Resonance Spectroscopy ◽

Bacterial Communication ◽

Homoserine Lactones ◽

Feeding Experiments ◽

Derivatives Of

ABSTRACT The role of intercellular communication in the regulation of bacterial multicellular behavior has received widespread attention, and a variety of signal molecules involved in bacterial communication have been discovered. In addition to the N-acyl-homoserine lactones, 4-hydroxy-2-alkylquinolines (HAQs), including the Pseudomonas quinolone signal, have been shown to function as signal molecules in Pseudomonas aeruginosa. In this study we unraveled the biosynthetic pathway of HAQs using feeding experiments with isotope-labeled precursors and analysis of extracted HAQs by gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy. Our results show that the biosynthesis of various HAQ metabolites is directed via a common metabolic pathway involving a “head-to-head” condensation of anthranilic acid and β-keto fatty acids. Moreover, we provide evidence that the β-keto-(do)decanoic acids, crucial for the biosynthesis of the heptyl and nonyl derivatives of the 4-hydroxyquinolines in P. aeruginosa, are at least in part derived from a common pool of β-hydroxy(do)decanoic acids involved in rhamnolipid biosynthesis.

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Sub-Inhibitory Concentrations of Ciprofloxacin Alone and Combinations with Plant-Derived Compounds against P. aeruginosa Biofilms and Their Effects on the Metabolomic Profile of P. aeruginosa Biofilms

Antibiotics ◽

10.3390/antibiotics10040414 ◽

2021 ◽

Vol 10 (4) ◽

pp. 414

Author(s):

Didem Kart ◽

Tuba Reçber ◽

Emirhan Nemutlu ◽

Meral Sagiroglu

Keyword(s):

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Inhibitory Concentration ◽

Molecular Level ◽

Metabolomic Profile ◽

Gene Expressions ◽

New Agents ◽

Qrt Pcr ◽

Metabolomic Approach

Introduction: Alternative anti-biofilm agents are needed to combat Pseudomonas aeruginosa infections. The mechanisms behind these new agents also need to be revealed at a molecular level. Materials and methods: The anti-biofilm effects of 10 plant-derived compounds on P. aeruginosa biofilms were investigated using minimum biofilm eradication concentration (MBEC) and virulence assays. The effects of ciprofloxacin and compound combinations on P. aeruginosa in mono and triple biofilms were compared. A metabolomic approach and qRT-PCR were applied to the biofilms treated with ciprofloxacin in combination with baicalein, esculin hydrate, curcumin, and cinnamaldehyde at sub-minimal biofilm inhibitory concentration (MBIC) concentrations to highlight the specific metabolic shifts between the biofilms and to determine the quorum sensing gene expressions, respectively. Results: The combinations of ciprofloxacin with curcumin, baicalein, esculetin, and cinnamaldehyde showed more reduced MBICs than ciprofloxacin alone. The quorum sensing genes were downregulated in the presence of curcumin and cinnamaldehyde, while upregulated in the presence of baicalein and esculin hydrate rather than for ciprofloxacin alone. The combinations exhibited different killing effects on P. aeruginosa in mono and triple biofilms without affecting its virulence. The findings of the decreased metabolite levels related to pyrimidine and lipopolysaccharide synthesis and to down-regulated alginate and lasI expressions strongly indicate the role of multifactorial mechanisms for curcumin-mediated P. aeruginosa growth inhibition. Conclusions: The use of curcumin, baicalein, esculetin, and cinnamaldehyde with ciprofloxacin will help fight against P. aeruginosa biofilms. To the best of our knowledge, this is the first study of its kind to define the effect of plant-based compounds as possible anti-biofilm agents with low MBICs for the treatment of P. aeruginosa biofilms through metabolomic pathways.

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Evidence of Quorum Sensing in Cyanobacteria by Homoserine Lactones: The Origin of Blooms

Water ◽

10.3390/w13131831 ◽

2021 ◽

Vol 13 (13) ◽

pp. 1831

Author(s):

Natalia Herrera ◽

Fernando Echeverri

Keyword(s):

Cell Proliferation ◽

Quorum Sensing ◽

Microcystis Aeruginosa ◽

Industrial Effluents ◽

Cyanobacterial Blooms ◽

Cylindrospermopsis Raciborskii ◽

Bacterial Communication ◽

Homoserine Lactones ◽

Exogenous Compounds ◽

Almost All

Although several theories have been postulated to explain cyanobacterial blooms, their biochemical origin has not yet been found. In this work, we explore the existence of bacterial communication, called quorum sensing, in Microcystis aeruginosa and Cylindrospermopsis raciborskii. Thus, the application of several known acylhomoserine lactones to cultures of both cyanobacteria causes profound metabolic. At 72 h post-application, some of them produced substantial increases in cell proliferation, while others were inhibitors. There was a correlation with colony-forming activity for most of them. According to ELISA analysis, the microcystin levels were increased with some lactones. However, there was a clear difference between M. aeruginosa and C. raciborskii culture since, in the first one, there was an inducing effect on cell proliferation, while in C. raciborskii, the effects were minor. Besides, there were compound inhibitors and inducers of microcystins production in M. aeruginosa, but almost all compounds were only inducers of saxitoxin production in C. raciborskii. Moreover, each lactone appears to be involved in a specific quorum sensing process. From these results, the formation of cyanobacterial blooms in dams and reservoirs could be explained since lactones may come from cyanobacteria and other sources as bacterial microflora-associated or exogenous compounds structurally unrelated to lactones, such as drugs, industrial effluents, and agrochemicals.

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