Redox-Active Antibiotics Control Gene Expression and Community Behavior in Divergent Bacteria

Dietrich, Lars E. P.; Teal, Tracy K.; Price-Whelan, Alexa; Newman, Dianne K.

doi:10.1126/science.1160619

Cited by 368 publications

(410 citation statements)

References 31 publications

Supporting

Mentioning

392

Contrasting

Order By: Relevance

“…Indeed, owing to the high pH (7.9) and CaCO 3 content of the Châteaurenard soil, the concentration of extractable iron was shown to be 15 times lower than that in the Carquefou soil (Lemanceau et al, 1988). As phenazines are redox-active antibiotics (Dietrich et al, 2008) and may contribute to iron mobilization in soils (Hernandez et al, 2004;Price-Whelan et al, 2006;Wang and Newman, 2008), the ability of bacteria to produce these metabolites may give them a competitive advantage under the iron-limiting conditions prevailing in the Châteaurenard suppressive soil.…”

Section: Discussionmentioning

confidence: 99%

“…Interestingly, the additional suppression provided by the bacterial and fungal combination was ascribed earlier to an interplay between carbon and iron competition achieved by these two groups of antagonistic microorganisms (Lemanceau et al, 1988: pyoverdine-mediated iron competition achieved by the fluorescent pseudomonads was shown to reduce the efficacy of carbon metabolism of the pathogenic F. oxysporum making it more susceptible to carbon competition with non-pathogenic F. oxysporum . Considering that phenazines are redox-active antibiotics (Dietrich et al, 2008) and may contribute to iron mobilization in soils (Hernandez et al, 2004;Price-Whelan et al, 2006), they also could play a role in iron competition, thereby making pathogenic F. oxysporum more susceptible to carbon competition with non-pathogenic F. oxysporum. Alternatively, phenazines also could act against pathogenic F. oxysporum as redox-active antibiotics leading to the accumulation of toxic oxygen radicals .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Phenazine antibiotics produced by fluorescent pseudomonads contribute to natural soil suppressiveness to Fusarium wilt

et al. 2009

View full text Add to dashboard Cite

Natural disease-suppressive soils provide an untapped resource for the discovery of novel beneficial microorganisms and traits. For most suppressive soils, however, the consortia of microorganisms and mechanisms involved in pathogen control are unknown. To date, soil suppressiveness to Fusarium wilt disease has been ascribed to carbon and iron competition between pathogenic Fusarium oxysporum and resident non-pathogenic F. oxysporum and fluorescent pseudomonads. In this study, the role of bacterial antibiosis in Fusarium wilt suppressiveness was assessed by comparing the densities, diversity and activity of fluorescent Pseudomonas species producing 2,4-diacetylphloroglucinol (DAPG) (phlD+) or phenazine (phzC+) antibiotics. The frequencies of phlD+ populations were similar in the suppressive and conducive soils but their genotypic diversity differed significantly. However, phlD genotypes from the two soils were equally effective in suppressing Fusarium wilt, either alone or in combination with non-pathogenic F. oxysporum strain Fo47. A mutant deficient in DAPG production provided a similar level of control as its parental strain, suggesting that this antibiotic does not play a major role. In contrast, phzC+ pseudomonads were only detected in the suppressive soil. Representative phzC+ isolates of five distinct genotypes did not suppress Fusarium wilt on their own, but acted synergistically in combination with strain Fo47. This increased level of disease suppression was ascribed to phenazine production as the phenazine-deficient mutant was not effective. These results suggest, for the first time, that redox-active phenazines produced by fluorescent pseudomonads contribute to the natural soil suppressiveness to Fusarium wilt disease and may act in synergy with carbon competition by resident non-pathogenic F. oxysporum.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Phenazine antibiotics produced by fluorescent pseudomonads contribute to natural soil suppressiveness to Fusarium wilt

et al. 2009

View full text Add to dashboard Cite

show abstract

“…Recently, pyocyanin was shown to have a function in signalling, responsible for the upregulation of specific genes, such as the genes involved in ferric iron acquisition and of the operon encoding the efflux pump MexGHI-OpmD PriceWhelan et al, 2006). Recently, it was shown that phenazine-defective mutants produce wrinkled colonies and accumulate NADH in the cells (Dietrich et al, 2008;Price-Whelan et al, 2007;Wangt & Newman, 2008). Pyocyanin is the phenazine that interacts most strongly with oxygen (Wangt & Newman, 2008) and it was proposed by Price-Whelan et al (2007) that externally added pyocyanin could give electrons to molecular oxygen to reduce it to water by oxidizing internal NADH to NAD.…”

Section: Discussionmentioning

confidence: 99%

The Pseudomonas aeruginosa oxidative stress regulator OxyR influences production of pyocyanin and rhamnolipids: protective role of pyocyanin

et al. 2010

View full text Add to dashboard Cite

The LysR-type transcriptional regulator (LTTR) OxyR orchestrates the defence of the opportunistic pathogen Pseudomonas aeruginosa against reactive oxygen species. In previous work we also demonstrated that OxyR is needed for the utilization of the ferrisiderophore pyoverdine, stressing the importance of this regulator. Here, we show that an oxyR mutant is unable to swarm on agar plates, probably as a consequence of absence of production of rhamnolipid surfactant molecules. Another obvious phenotypic change was the increased production of the phenazine redox-active molecule pyocyanin in the oxyR mutant. As already described, the oxyR mutant could not grow in LB medium, unless high numbers of cells (>108 ml−1) were inoculated. However, its growth in Pseudomonas P agar (King's A), a medium inducing pyocyanin production, was like that of the wild-type, suggesting a protective action of this redox-active phenazine compound. This was confirmed by the restoration of the capacity to grow in LB medium upon addition of pure pyocyanin. Although both rhamnolipid and pyocyanin production are controlled by quorum sensing, no obvious changes were observed in the production of N-acylhomoserine lactones or the Pseudomonas quinolone signal (PQS). Complementation of rhamnolipid production and motility, and restoration of normal pyocyanin levels, was only possible when the oxyR gene was in single copy, while pyocyanin levels were increased when oxyR was present in a multicopy vector. Conversely, plating efficiency was increased only when the oxyR gene was present in multicopy, but not when in single copy in the chromosome, due to lower expression of oxyR compared with the wild-type, suggesting that some phenotypes are differently affected in function to the levels of OxyR molecules in the cell. Analysis of transcripts of oxidative stress-response enzymes showed a strong decrease of katB, ahpC and ahpB expression in the oxyR mutant grown in LB, but this was not the case when the mutant was grown on P agar, suggesting that the OxyR dependency for the transcription of these genes is not total.

show abstract

“…Pseudomonas aeruginosa, along with a variety of other bacteria, produce redox-cycling antibiotics called phenazines (29,41). In susceptible bacteria such as E. coli, phenazines enter the cell and produce superoxide by oxidizing cytoplasmic targets and reducing molecular oxygen (42).…”

Section: Curliated Bacteria Are Localized To the Air-biofilm Interfacmentioning

confidence: 99%

“…Along with curli, cellulose aids cell-to-cell attachment and adherence to inorganic surfaces and host cells (24)(25)(26). UTI89 and a variety of other bacterial species form rugose biofilms (also known as rdar) on agar plates (4,23,(27)(28)(29). In both S. typhimurium and E. coli, the CsgD-regulated matrix components curli and cellulose are necessary for development of rugose biofilms (23,27,30).…”

mentioning

confidence: 99%

Iron induces bimodal population development by Escherichia coli

DePas¹,

Hufnagel

Lee

et al. 2013

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

110

View full text Add to dashboard Cite

Bacterial biofilm formation is a complex developmental process involving cellular differentiation and the formation of intricate 3D structures. Here we demonstrate that exposure to ferric chloride triggers rugose biofilm formation by the uropathogenic Escherichia coli strain UTI89 and by enteric bacteria Citrobacter koseri and Salmonella enterica serovar typhimurium. Two unique and separable cellular populations emerge in iron-triggered, rugose biofilms. Bacteria at the air-biofilm interface express high levels of the biofilm regulator csgD, the cellulose activator adrA, and the curli subunit operon csgBAC. Bacteria in the interior of rugose biofilms express low levels of csgD and undetectable levels of matrix components curli and cellulose. Iron activation of rugose biofilms is linked to oxidative stress. Superoxide generation, either through addition of phenazine methosulfate or by deletion of sodA and sodB, stimulates rugose biofilm formation in the absence of high iron. Additionally, overexpression of Mn-superoxide dismutase, which can mitigate iron-derived reactive oxygen stress, decreases biofilm formation in a WT strain upon iron exposure. Not only does reactive oxygen stress promote rugose biofilm formation, but bacteria in the rugose biofilms display increased resistance to H 2 O 2 toxicity. Altogether, we demonstrate that iron and superoxide stress trigger rugose biofilm formation in UTI89. Rugose biofilm development involves the elaboration of two distinct bacterial populations and increased resistance to oxidative stress.functional amyloid | biofilm matrix | wrinkled colony

show abstract

Redox-Active Antibiotics Control Gene Expression and Community Behavior in Divergent Bacteria

Cited by 368 publications

References 31 publications

Phenazine antibiotics produced by fluorescent pseudomonads contribute to natural soil suppressiveness to Fusarium wilt

Phenazine antibiotics produced by fluorescent pseudomonads contribute to natural soil suppressiveness to Fusarium wilt

The Pseudomonas aeruginosa oxidative stress regulator OxyR influences production of pyocyanin and rhamnolipids: protective role of pyocyanin

Iron induces bimodal population development by Escherichia coli

Contact Info

Product

Resources

About