The Pho regulon influences biofilm formation and type three secretion in <i>Pseudomonas aeruginosa</i>

Haddad, Ahmed; Jensen, Vanessa; Becker, Tanja; Häußler, Susanne

doi:10.1111/j.1758-2229.2009.00049.x

Cited by 27 publications

(16 citation statements)

References 45 publications

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“…These data suggest that P. aeruginosa cells will be highly deficient in phosphorus uptake and metabolism. It should also be noted that the Pho regulon has been reported to influence biofilm formation capacity and pathogenicity35.…”

Section: Resultsmentioning

confidence: 99%

Understanding the antimicrobial mechanism of TiO2-based nanocomposite films in a pathogenic bacterium

Kubacka

Diez

Rojo

et al. 2014

Sci Rep

382

241

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Titania (TiO2)-based nanocomposites subjected to light excitation are remarkably effective in eliciting microbial death. However, the mechanism by which these materials induce microbial death and the effects that they have on microbes are poorly understood. Here, we assess the low dose radical-mediated TiO2 photocatalytic action of such nanocomposites and evaluate the genome/proteome-wide expression profiles of Pseudomonas aeruginosa PAO1 cells after two minutes of intervention. The results indicate that the impact on the gene-wide flux distribution and metabolism is moderate in the analysed time span. Rather, the photocatalytic action triggers the decreased expression of a large array of genes/proteins specific for regulatory, signalling and growth functions in parallel with subsequent selective effects on ion homeostasis, coenzyme-independent respiration and cell wall structure. The present work provides the first solid foundation for the biocidal action of titania and may have an impact on the design of highly active photobiocidal nanomaterials.

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Section: Resultsmentioning

confidence: 99%

Understanding the antimicrobial mechanism of TiO2-based nanocomposite films in a pathogenic bacterium

Kubacka

Diez

Rojo

et al. 2014

Sci Rep

382

241

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“…There are several well-described host-specific environmental factors that have an impact on and drive bacterial pathogenicity. These include the higher host temperature, scarcity of iron, and alterations in the concentration of phosphate, pH, oxygen tension, and osmolality [43][44][45][46]. Furthermore, there is increasing evidence that the host-specific fatty acid composition during an infection process can be added to the list of factors that are sensed by the bacteria to induce a virulence phenotype.…”

Section: Discussionmentioning

confidence: 99%

Establishment of an induced memory response in Pseudomonas aeruginosa during infection of a eukaryotic host

et al. 2019

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In a given habitat, bacterial cells often experience recurrent exposures to the same environmental stimulus. The ability to memorize the past event and to adjust current behaviors can lead to efficient adaptation to the recurring stimulus. Here we demonstrate that the versatile bacterium Pseudomonas aeruginosa adopts a virulence phenotype after serial passage in the invertebrate model host Galleria mellonella. The virulence phenotype was not linked to the acquisition of genetic variations and was sustained for several generations, despite cultivation of the ex vivo virulence-adapted P. aeruginosa cells under rich medium conditions in vitro. Transcriptional reprogramming seemed to be induced by a host-specific food source, as reprogramming was also observed upon cultivation of P. aeruginosa in rich medium supplemented with polyunsaturated long-chain fatty acids. The establishment of induced memory responses adds a time dimension and seems to fill the gap between long-term evolutionary genotypic adaptation and short-term induced individual responses. Efforts to unravel the fundamental mechanisms that underlie the carry-over effect to induce such memory responses will continue to be of importance as hysteretic behavior can serve survival of bacterial populations in changing and challenging habitats.

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“…In this study, we show that activation of the transcriptional regulator PhoB promotes biofilm formation in phosphate-starvation conditions and in the pst mutant where PhoB is derepressed. Activation of PhoB has been shown to affect biofilm formation in different bacterial species (8, 9, 11, 12, 14, 15, 29). Upon depletion of phosphate, the plant pathogen A. tumefaciens was shown to increase its biofilm formation.…”

Section: Discussionmentioning

confidence: 99%

“…In addition to being involved in phosphate homeostasis, the Pho regulon has been connected to bacterial virulence and biofilm formation in several species including Pseudomonas aeruginosa, P. aureofaciens, P. fluorescens, Agrobacterium tumefaciens, Vibrio cholerae, Bacillus anthracis , and Cronobacter sakazakii (8–15). Recent studies established that E. coli O157:H7 strains are able to form biofilms in different environments such as food surfaces, processing plants, and water (16, 17).…”

Section: Introductionmentioning

confidence: 99%

Escherichia coliO157:H7 responds to phosphate starvation by modifying LPS involved in biofilm formation

Vogeleer

Vincent

Chekabab

et al. 2019

Preprint

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27In open environments such as water, enterohemorrhagic Escherichia coli O157:H7 responds to 28 inorganic phosphate (Pi) starvation by inducing the Pho regulon controlled by PhoB. The 29 phosphate-specific transport (Pst) system is the high-affinity Pi transporter. In the Δpst mutant, 30PhoB is constitutively activated and regulates the expression of genes from the Pho regulon. In 31 E. coli O157:H7, the Δpst mutant, biofilm, and autoagglutination were increased. In the double-32 deletion mutant Δpst ΔphoB, biofilm and autoagglutination were similar to the wild-type strain, 33suggesting that PhoB is involved. We investigated the relationship between PhoB activation 34 and enhanced biofilm formation by screening a transposon mutant library derived from Δpst 35 mutant for decreased autoagglutination and biofilms mutants. Lipopolysaccharide (LPS) genes 36 involved in the synthesis of the LPS core were identified. Transcriptomic studies indicate the 37 influence of Pi-starvation and pst mutation on LPS biosynthetic gene expression. LPS analysis 38 indicated that the O-antigen was deficient in the Δpst mutant. Interestingly, waaH, encoding a 39 glycosyltransferase associated with LPS modifications in E. coli K-12, was highly expressed in 40 the Δpst mutant of E. coli O157:H7. Deletion of waaH from the Δpst mutant and from the wild-41 type strain grown in Pi-starvation conditions decreased the biofilm formation but without 42 affecting LPS. Our findings suggest that LPS core is involved in the autoagglutination and 43 biofilm phenotypes of the Δpst mutant and that WaaH plays a role in biofilm in response to starvation. This study highlights the importance of Pi-starvation in biofilm formation of E. coli 45 O157:H7, which may affect its transmission and persistence. 46 47 IMPORTANCE Enterohemorrhagic Escherichia coli O157:H7 is a human pathogen 48 responsible for bloody diarrhea and renal failures. In the environment, O157:H7 can survive for 49 prolonged periods of time under nutrient-deprived conditions. Biofilms are thought to 50 participate in this environmental lifestyle. Previous reports have shown that the availability of 51 4 extracellular inorganic phosphate (Pi) affected bacterial biofilm formation; however, nothing 52 was known about O157:H7 biofilm formation. Our results show that O157:H7 membrane 53 undergoes modifications upon PhoB activation leading to increased biofilm formation. A 54 mutation in the Pst system results in reduced amount of the smooth type LPS and that this could 55 influence the biofilm composition. This demonstrates how the E. coli O157:H7 adapts to Pi 56 starvation increasing its ability to occupy different ecological niches. 57 58 Keyword: EHEC, biofilm, phosphate, LPS, Pho regulon 59 library for decreased ability to agglutinate and to form a biofilm, genes in LPS biosynthetic 102 pathways were over-represented. Further analysis revealed that LPS of Δpst mutant is lacking 103 O-antigen repeats but that its core oligosaccharide was necessary for biofilm formation and 104 agglutination....

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The Pho regulon influences biofilm formation and type three secretion in Pseudomonas aeruginosa

Cited by 27 publications

References 45 publications

Understanding the antimicrobial mechanism of TiO2-based nanocomposite films in a pathogenic bacterium

Understanding the antimicrobial mechanism of TiO2-based nanocomposite films in a pathogenic bacterium

Establishment of an induced memory response in Pseudomonas aeruginosa during infection of a eukaryotic host

Escherichia coliO157:H7 responds to phosphate starvation by modifying LPS involved in biofilm formation

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