ChIP-Seq and RNA-Seq Reveal an AmrZ-Mediated Mechanism for Cyclic di-GMP Synthesis and Biofilm Development by Pseudomonas aeruginosa

Jones, Chris J.; Newsom, David E.; Kelly, Benjamin J.; Irie, Yasuhiko; Jennings, Laura K.; Xu, Binjie; Limoli, Dominique H.; Harrison, Joe J.; Parsek, Matthew R.; White, Peter; Wozniak, Daniel J.

doi:10.1371/journal.ppat.1003984

Cited by 141 publications

(245 citation statements)

References 101 publications

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“…Overnight cultures of S. aureus were grown in TSB and diluted 1:1,000 into fresh TSB or TSB-G. Cultures were grown with shaking at 37°C for the durations indicated, and samples were prepared for analysis as described for c-di-GMP (54). Briefly, cell pellets were washed twice with cold molecular grade water (Corning).…”

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confidence: 99%

Genome-wide screen for genes involved in eDNA release during biofilm formation by Staphylococcus aureus

DeFrancesco

Masloboeva

Syed

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

103

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Staphylococcus aureus is a leading cause of both nosocomial and community-acquired infection. Biofilm formation at the site of infection reduces antimicrobial susceptibility and can lead to chronic infection. During biofilm formation, a subset of cells liberate cytoplasmic proteins and DNA, which are repurposed to form the extracellular matrix that binds the remaining cells together in large clusters. Using a strain that forms robust biofilms in vitro during growth under glucose supplementation, we carried out a genome-wide screen for genes involved in the release of extracellular DNA (eDNA). A high-density transposon insertion library was grown under biofilm-inducing conditions, and the relative frequency of insertions was compared between genomic DNA (gDNA) collected from cells in the biofilm and eDNA from the matrix. Transposon insertions into genes encoding functions necessary for eDNA release were identified by reduced representation in the eDNA. On direct testing, mutants of some of these genes exhibited markedly reduced levels of eDNA and a concomitant reduction in cell clustering. Among the genes with robust mutant phenotypes were gdpP, which encodes a phosphodiesterase that degrades the second messenger cyclic-di-AMP, and xdrA, the gene for a transcription factor that, as revealed by RNA-sequencing analysis, influences the expression of multiple genes, including many involved in cell wall homeostasis. Finally, we report that growth in biofilm-inducing medium lowers cyclicdi-AMP levels and does so in a manner that depends on the gdpP phosphodiesterase gene.Staphylococcus aureus | biofilm | eDNA | cyclic-di-AMP

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confidence: 99%

Genome-wide screen for genes involved in eDNA release during biofilm formation by Staphylococcus aureus

DeFrancesco

Masloboeva

Syed

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

103

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“…In contrast, while BdlA is detectable only in its intact form in planktonic cells, plasmid-borne overexpression of the gene PA4843 triggered BdlA cleavage in planktonic cells (38). PA4843 encodes the recently characterized active DGC GcbA (also identified as AdcA), which was found to be involved in the regulation of the transition from planktonic to surface-associated growth (39,40). Although BdlA plays a pivotal and central role in enabling P. aeruginosa biofilm dispersion in response to a variety of environmental cues, the system contributing to the elevation of c-di-GMP levels responsible for BdlA posttranslational modification and activation is currently not known.…”

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confidence: 99%

The Diguanylate Cyclase GcbA Facilitates Pseudomonas aeruginosa Biofilm Dispersion by Activating BdlA

2015

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Biofilm dispersion is a highly regulated process that allows biofilm bacteria to respond to changing environmental conditions and to disseminate to new locations. The dispersion of biofilms formed by the opportunistic pathogen Pseudomonas aeruginosa is known to require a number of cyclic di-GMP (c-di-GMP)-degrading phosphodiesterases (PDEs) and the chemosensory protein BdlA, with BdlA playing a pivotal role in regulating PDE activity and enabling dispersion in response to a wide array of cues. BdlA is activated during biofilm growth via posttranslational modifications and nonprocessive cleavage in a manner that is dependent on elevated c-di-GMP levels. Here, we provide evidence that the diguanylate cyclase (DGC) GcbA contributes to the regulation of BdlA cleavage shortly after initial cellular attachment to surfaces and, thus, plays an essential role in allowing biofilm cells to disperse in response to increasing concentrations of a variety of substances, including carbohydrates, heavy metals, and nitric oxide. DGC activity of GcbA was required for its function, as a catalytically inactive variant could not rescue impaired BdlA processing or the dispersion-deficient phenotype of gcbA mutant biofilms to wild-type levels. While modulating BdlA cleavage during biofilm growth, GcbA itself was found to be subject to c-di-GMP-dependent and growth-mode-specific regulation. GcbA production was suppressed in mature wild-type biofilms and could be induced by reducing c-di-GMP levels via overexpression of genes encoding PDEs. Taken together, the present findings demonstrate that the regulatory functions of c-di-GMP-synthesizing DGCs expand beyond surface attachment and biofilm formation and illustrate a novel role for DGCs in the regulation of the reverse sessile-motile transition of dispersion.T he process of biofilm dispersion represents an important and highly regulated phenotypic switch that allows cells residing within a biofilm to respond to changing conditions outside and within biofilm structures and to evade environmental stresses. Dispersion occurs in response to a wide array of signals, with dispersion-inducing conditions ranging from directly sensed environmental cues to self-synthesized signaling molecules (1-6). Biofilm dispersion in various bacterial species, including Aeromonas hydrophila, Pseudomonas aeruginosa, Pseudomonas putida, and Pseudomonas fluorescens, is tightly linked to nutrient availability, with both elevation and reduction in available nutrients, such as carbon and nitrogen sources, having been previously reported to trigger the process (1, 2, 7-12). Additional environmental dispersion triggers include temperature changes (13), oxidative and nitrosative stress (4, 14, 15), oxygen limitation (16, 17), and iron availability (18). More recently, the accumulation of D-amino acids has been found to trigger dispersion of biofilms formed by Bacillus subtilis and to prevent biofilm formation by P. aeruginosa and Staphylococcus aureus, with various reports suggesting that the mechanism of action may b...

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“…Owing to their resistance to antibiotics and antiphagocytic effects, biofilms can frequently cause persistent chronic infections that are difficult to treat. Biofilms are significant causes of morbidity and mortality (2,3). At least 65% of all bacterial infections are associated with biofilm (2,3).…”

Section: Introductionmentioning

confidence: 99%

“…Biofilms are significant causes of morbidity and mortality (2,3). At least 65% of all bacterial infections are associated with biofilm (2,3). Infections such as natural valve endocarditis, otitis media, chronic bacterial prostatitis, cystic fibrosis, and periodontitis develop as a result of biofilms that form on living surfaces.…”

Section: Introductionmentioning

confidence: 99%

The comparison of various disinfectants’ efficacy on Staphylococcus aureus and Pseudomonas aeruginosa biofilm layers

Köse¹,

Yapar²

2017

Turk J Med Sci

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IntroductionA biofilm can be defined as a well-organized microbial community in the extracellular polymeric substance (EPS) that adheres to living or inanimate surfaces (1). Owing to their resistance to antibiotics and antiphagocytic effects, biofilms can frequently cause persistent chronic infections that are difficult to treat. Biofilms are significant causes of morbidity and mortality (2,3). At least 65% of all bacterial infections are associated with biofilm (2,3). Infections such as natural valve endocarditis, otitis media, chronic bacterial prostatitis, cystic fibrosis, and periodontitis develop as a result of biofilms that form on living surfaces. The medical devices on which biofilms can develop include prosthetic heart valves, central venous catheters, urinary catheters, contact lenses, and intrauterine devices (4). Due to the high rates of mortality and morbidity associated with biofilms, several studies have been conducted on antimicrobials and particularly on the effectiveness of antibiotics against biofilms. It has been demonstrated that antibiotics show limited efficacy against biofilms as the biofilm layer persists. For this reason, it should be borne in mind that disinfectants serve as a significant alternative against human mucosa and biofilms on the surfaces of medical device (5). This study aims at investigating the effectiveness of orthophthalaldehyde, peracetic acid, hydrogen peroxide, and sodium hypochlorite against Pseudomonas aeruginosa and Staphylococcus aureus biofilm layers and the live microbial cells on the biofilm layers. Material and methods Bacterial strainsS. aureus (ATCC 6538) and P. aeruginosa (PA01) bacterial strains that are known to produce biofilms were selected (5,6). Bacterial cells stocked at -80 °C were passaged to a tryptic soy agar (TSA) plate (Merck). After being incubated for 24 h at 35-37 °C, a bacterial solution was Background/aim: Because biofilms are resistant to antibiotics and biocides, they usually cause chronic persistent infections, which are arduous to cure and have high mortality and morbidity. Our study aimed to investigate the efficiency of orthophthalaldehyde, peracetic acid, hydrogen peroxide, and sodium hypochlorite on Pseudomonas aeruginosa and Staphylococcus aureus biofilm layers and live microbial cells.Materials and methods: Biofilm layers were determined by crystal violet assay and live microbial cells were determined using a resazurin assay.Results: For Pseudomonas aeruginosa, sodium hypochlorite showed the most influential disinfection because it diminished 83.6% of the biofilm layer and decreased 99.7% of live microbial cells. For Staphylococcus aureus, hydrogen peroxide was determined the most active disinfectant with 80.3% reduction of the biofilm layer. Sodium hypochlorite was also determined to be the most efficient disinfectant with 99.8% reduction of live microbial cells. Sodium hypochlorite was the most influential disinfectant on biofilm layers and live microbial cells of both microorganisms. Conclusion:We concluded that if we use sodi...

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ChIP-Seq and RNA-Seq Reveal an AmrZ-Mediated Mechanism for Cyclic di-GMP Synthesis and Biofilm Development by Pseudomonas aeruginosa

Cited by 141 publications

References 101 publications

Genome-wide screen for genes involved in eDNA release during biofilm formation by Staphylococcus aureus

Genome-wide screen for genes involved in eDNA release during biofilm formation by Staphylococcus aureus

The Diguanylate Cyclase GcbA Facilitates Pseudomonas aeruginosa Biofilm Dispersion by Activating BdlA

The comparison of various disinfectants’ efficacy on Staphylococcus aureus and Pseudomonas aeruginosa biofilm layers

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