Coordination of Swarming Motility, Biosurfactant Synthesis, and Biofilm Matrix Exopolysaccharide Production in Pseudomonas aeruginosa

Wang, Shiwei; Yu, Shan; Zhang, Zhenyin; Wei, Qing; Yan, Lü; Ai, Guomin; Liu, Huan; Zhang, Luyan

doi:10.1128/aem.01237-14

Cited by 95 publications

(84 citation statements)

References 47 publications

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“…These results indicated that high iron levels inhibited the expression of RhlI/RhlR and RhlAB in order to reduce the rhamnolipid biosynthesis. This revealed another way that iron stimulated Psl production in P. aeruginosa at the posttranslational level because the decrease in rhamnolipid production can increase Psl production (57).…”

Section: Resultsmentioning

confidence: 99%

A Survival Strategy for Pseudomonas aeruginosa That Uses Exopolysaccharides To Sequester and Store Iron To Stimulate Psl-Dependent Biofilm Formation

Wei

Zhao

et al. 2016

Appl Environ Microbiol

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Exopolysaccharide Psl is a critical biofilm matrix component in Pseudomonas aeruginosa, which forms a fiber-like matrix to enmesh bacterial communities. Iron is important for P. aeruginosa biofilm development, yet it is not clearly understood how iron contributes to biofilm development. Here, we showed that iron promoted biofilm formation via elevating Psl production in P. aeruginosa. The high level of iron stimulated the synthesis of Psl by reducing rhamnolipid biosynthesis and inhibiting the expression of AmrZ, a repressor of psl genes. Iron-stimulated Psl biosynthesis and biofilm formation held true in mucoid P. aeruginosa strains. Subsequent experiments indicated that iron bound with Psl in vitro and in biofilms, which suggested that Psl fibers functioned as an iron storage channel in P. aeruginosa biofilms. Moreover, among three matrix exopolysaccharides of P. aeruginosa, Psl is the only exopolysaccharide that can bind with both ferrous and ferric ion, yet with higher affinity for ferrous iron. Our data suggest a survival strategy of P. aeruginosa that uses exopolysaccharide to sequester and store iron to stimulate Psl-dependent biofilm formation. IMPORTANCEPseudomonas aeruginosa is an environmental microorganism which is also an opportunistic pathogen that can cause severe infections in immunocompromised individuals. It is the predominant airway pathogen causing morbidity and mortality in individuals affected by the genetic disease cystic fibrosis (CF). Increased airway iron and biofilm formation have been proposed to be the potential factors involved in the persistence of P. aeruginosa in CF patients. Here, we showed that a high level of iron enhanced the production of the key biofilm matrix exopolysaccharide Psl to stimulate Psl-dependent biofilm formation. Our results not only make the link between biofilm formation and iron concentration in CF, but also could guide the administration or use of iron chelators to interfere with biofilm formation in P. aeruginosa in CF patients. Furthermore, our data also imply a survival strategy of P. aeruginosa under high-iron environmental conditions. P seudomonas aeruginosa is a ubiquitous environmental microorganism. It is also an opportunistic pathogen that is often found in the hospital environment. P. aeruginosa can cause severe acute nosocomial infections in immunocompromised individuals or chronic lung infections in cystic fibrosis (CF) patients (1). These infections generally persist despite the use of intensive antimicrobial therapy and have been linked to the formation of antibiotic-resistant biofilms, wherein bacterial cells were encased in an extracellular polymeric substance (EPS) matrix (2, 3). It is generally accepted that the biofilm matrix functions as both a structural scaffold and protective barrier for bacteria in biofilms (4, 5). The iron content of CF sputum is often highly increased compared to that in the sputum of healthy controls, which has also been considered a potential factor in the persistence of P. aeruginosa (6-8). Mineral elem...

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Section: Resultsmentioning

confidence: 99%

A Survival Strategy for Pseudomonas aeruginosa That Uses Exopolysaccharides To Sequester and Store Iron To Stimulate Psl-Dependent Biofilm Formation

Wei

Zhao

et al. 2016

Appl Environ Microbiol

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“…The negative influence of mixture consist of fengycin and surfactin produced by B. subtilis and B. licheniformis on E. coli and S. aureus adhesion was observed by Rivardo et al [23]. Wang et al [24] suggested that bacteria coordinate i.e. biosurfactants and exopolysaccharide production which mediated biofilm formation by mechanism in which competition for common sugar precursors mannose-1-phosphate (Man-1-P) and glucose-1-phosphate (Glc-1-P) used for both expopolysaccharides and rhamnolipids synthesis serves as control of the bacterial motility, biofilm formation and surfactants production.…”

Section: Eko-dok 2017mentioning

confidence: 90%

Norfloxacin degradation byBacillus subtilisstrains able to produce biosurfactants on a bioreactor scale

2017

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Abstract. The discharge of antibiotics into the environment has become a major concern since this group of pharmaceuticals influence on microbial communities not only by its mode of action, but also because of the risk of a worldwide dispersal of antibiotic resistance genes (ARG). Antibiotics residues have been found in various environments such as waters, sediments, and soils. Moreover, most WWTPs are not designed to treat such kind of pollutants, which remain incompletely removed. Currently, biodegradation processes which involved bacterial strains with increased degradation capabilities is one of the most promising technique. The aim of this study was to evaluate the norfloxacin biodegradation potential of the three Bacillus subtilis strains named T-1, T'-1 and I'-1a on a bioreactor scale. The aerobic degradation was conducted in a 5-liter bioreactor on minimal salts medium in co-metabolic culture supplemented with glucose. The degradation rate of norfloxacin was determined with the HPLC technique. The surface tension was determined using ring method in order to observe the changes in biosurfactants production. Also, the biofilm formation abilities of the bacteria with two quantitative methods, crystal violet (CV) method and TTC-based test and enzymes production were evaluated.

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“…31 In addition, studies have reported that nutritional condition, viscosity, and rhamnolipids contribute to swarming motility. 31,36 Pseudomonas aeruginosa cells may adjust to make an environment more favorable, then exert their virulence. The role of flagella involves not only movement for adhesion on corneal epithelium, but may also involve activation of immunity.…”

Section: Discussionmentioning

confidence: 99%

Relationship of Virulence Factors and Clinical Features in Keratitis Caused byPseudomonas aeruginosa

Oka

Suzuki

Ishikawa

et al. 2015

Invest. Ophthalmol. Vis. Sci.

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PURPOSE. To examine bacterial virulence factors in Pseudomonas aeruginosa isolates from contact lens (CL) wearers and non-CL wearers with P. aeruginosa keratitis, and to investigate relationships between virulence factors and clinical features of keratitis.METHODS. The study involved 25 subjects including 18 CL and 7 non-CL-related P. aeruginosa keratitis patients. Slit-lamp photographs of all subjects were captured, and the focus occupancy ratio (FOR) was defined as the total focus area/entire cornea area, using image processing software. Twenty-five clinical P. aeruginosa isolates from keratitis were assessed for protease production, elastase production, biofilm formation, bacterial swimming and swarming motility, cell surface hydrophobicity, and genes encoding the type III secretion system (TTSS) effectors (ExoU and ExoS). RESULTS.Ring abscess was found in 9 of 18 CL-related P. aeruginosa keratitis cases (CL[þ] ring[þ] group) but not in another 9 cases (CL[þ] ring[À] group). Expression or prevalence of virulence factors in P. aeruginosa isolates from the CL(þ) ring(þ) group, CL(þ) ring(À) group, and CL(À) group were compared. The FOR for CL(þ) ring(þ) or CL(À) was higher than for CL(þ) ring(À) (P < 0.05 and P < 0.01, respectively). The rate of positive swimming motility for CL(þ) ring(þ) or CL(À) was higher than for CL(þ) ring(À) (P < 0.05), whereas the rate of positive swarming motility for CL(þ) ring(þ) was higher than for CL(þ) ring(À) or CL(À) (P < 0.05). Prevalence of an exoSþ/exoU-genotype for CL(þ) ring(þ) or CL(À) was higher than for CL(þ) ring(À) (P < 0.05). In the CL-related group, expression of elastase and swarming motility significantly correlated with FOR.CONCLUSIONS. Swimming motility, swarming motility, and TTSS ExoS could play a major role in the determination of clinical features of P. aeruginosa keratitis.Keywords: Pseudomonas aeruginosa, keratitis, virulence factors, protease, swarming motility K eratitis caused by Pseudomonas aeruginosa can progress rapidly with suppurative infiltration, and can lead to corneal perforation and melt, resulting in the loss of vision. 1Contact lens (CL) wearers are especially susceptible to development of P. aeruginosa keratitis. Ring abscess, which is a ring-shaped accumulation of polymorphonuclear leukocytes surrounding a central corneal lesion, is a well-known hallmark of P. aeruginosa keratitis.2,3 Along with ring abscess, serrated or satellite lesions with keratitis are sometimes found in P. aeruginosa keratitis.4,5 Pseudomonas aeruginosa can show various clinical features, but little is known about factors that determine these clinical features.To understand the mechanism of pathogenesis in keratitis caused by P. aeruginosa, the virulence factors as well as extracellular products, including proteases, 6-8 exotoxin A, 9 and biofilms, 10 have been investigated. Of these factors, proteases, including metalloproteases such as alkaline protease, elastase A, and elastase B, 11 are important in virulence. We recently reported that MucD protease inhibits neu...

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Coordination of Swarming Motility, Biosurfactant Synthesis, and Biofilm Matrix Exopolysaccharide Production in Pseudomonas aeruginosa

Cited by 95 publications

References 47 publications

A Survival Strategy for Pseudomonas aeruginosa That Uses Exopolysaccharides To Sequester and Store Iron To Stimulate Psl-Dependent Biofilm Formation

A Survival Strategy for Pseudomonas aeruginosa That Uses Exopolysaccharides To Sequester and Store Iron To Stimulate Psl-Dependent Biofilm Formation

Norfloxacin degradation byBacillus subtilisstrains able to produce biosurfactants on a bioreactor scale

Relationship of Virulence Factors and Clinical Features in Keratitis Caused byPseudomonas aeruginosa

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