EFFECT OF TOPOGRAPHICALLY PATTERNED POLY(DIMETHYLSILOXANE) SURFACES ON Pseudomonas aeruginosa ADHESION AND BIOFILM FORMATION

Nano LIFE ◽  
2012 ◽  
Vol 02 (04) ◽  
pp. 1242004 ◽  
Author(s):  
JOHN F. LING ◽  
MARY V. GRAHAM ◽  
NATHANIEL C. CADY
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Lower Surface ◽  
Bacterial Attachment ◽  
Initial Surface ◽  
Direct Role ◽  
Surface Attachment ◽  
Bacterial Surface ◽  
Static Conditions

Bacterial pathogens, such as Pseudomonas aeruginosa, readily form biofilms on surfaces, limiting the efficacy of antimicrobial and antibiotic treatments. To mitigate biofilm formation, surfaces are often treated with antimicrobial agents, which have limited lifetime and efficacy. Recent studies have shown that well-ordered topographic patterns can limit bacterial attachment to surfaces and limit biofilm formation. In this study, nano and microscale patterned poly(dimethylsiloxane) surfaces were evaluated for their ability to affect adhesion and biofilm formation by Pseudomonas aeruginosa. Feature size and spacing were varied from 500 nm to 2 μm and included repeating arrays of square pillars, holes, lines and biomimetc Sharklet™ patterns. Bacterial surface adhesion and biofilm formation was assessed in microfluidic flow devices and under static conditions. Attachment profiles under static and fluid flow varied within topography types, sizes and spacing. Pillar structures of all sizes yielded lower surface attachment than line-based patterns and arrays of holes. This trend was also observed for biomimetic Sharklet™ patterns, with reduced bacterial attachment to "raised" features as compared to "recessed" features. Notably, none of the topographically patterned surfaces outperformed smooth surfaces (without topography) for resisting cell adhesion. Initial surface attachment patterns were indicative of subsequent biofilm formation and coverage, suggesting a direct role of surface topography in biofilm-based biofouling.

scholarly journals Organoselenium Coating on Cellulose Inhibits the Formation of Biofilms by Pseudomonas aeruginosa and Staphylococcus aureus

2009 ◽  
Vol 75 (11) ◽  
pp. 3586-3592 ◽  
Author(s):  
Phat L. Tran ◽  
Adrienne A. Hammond ◽  
Thomas Mosley ◽  
Janette Cortez ◽  
Tracy Gray ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Bacterial Attachment ◽  
Wound Dressings ◽  
Aqueous Environment ◽  
Burn Victims ◽  
Surgical Wounds

ABSTRACT Among the most difficult bacterial infections encountered in treating patients are wound infections, which may occur in burn victims, patients with traumatic wounds, necrotic lesions in people with diabetes, and patients with surgical wounds. Within a wound, infecting bacteria frequently develop biofilms. Many current wound dressings are impregnated with antimicrobial agents, such as silver or antibiotics. Diffusion of the agent(s) from the dressing may damage or destroy nearby healthy tissue as well as compromise the effectiveness of the dressing. In contrast, the antimicrobial agent selenium can be covalently attached to the surfaces of a dressing, prolonging its effectiveness. We examined the effectiveness of an organoselenium coating on cellulose discs in inhibiting Pseudomonas aeruginosa and Staphylococcus aureus biofilm formation. Colony biofilm assays revealed that cellulose discs coated with organoselenium completely inhibited P. aeruginosa and S. aureus biofilm formation. Scanning electron microscopy of the cellulose discs confirmed these results. Additionally, the coating on the cellulose discs was stable and effective after a week of incubation in phosphate-buffered saline. These results demonstrate that 0.2% selenium in a coating on cellulose discs effectively inhibits bacterial attachment and biofilm formation and that, unlike other antimicrobial agents, longer periods of exposure to an aqueous environment do not compromise the effectiveness of the coating.

scholarly journals Topographical biomaterials instruct bacterial surface attachment and the in vivo host-pathogen response

2020 ◽  
Author(s):  
Manuel Romero ◽  
Jeni Luckett ◽  
Grazziela Figueredo ◽  
Alessandro M. Carabelli ◽  
Aurélie Carlier ◽  
...  
Keyword(s):  
Specific Surface ◽  
Biofilm Formation ◽  
Bacterial Attachment ◽  
Bacterial Biofilm ◽  
Healthcare Sector ◽  
Infection Model ◽  
Surface Attachment ◽  
Bacterial Surface ◽  
Surface Topographies ◽  
Biofilm Development

ABSTRACTThe prevention of biofilm development on the surfaces of implanted medical devices is a global challenge for the healthcare sector. Bio-instructive materials that intrinsically prevent bacterial biofilm formation and drive an appropriate host immune response are required to reduce the burden of healthcare associated infections. Although bacterial surface attachment is sensitive to micro- and nano-surface topographies, its exploitation has been limited by the lack of unbiased high throughput biomaterial screens combined with model-based methods capable of generating correlations and predicting generic responses. Consequently, we sought to fill this knowledge gap by using polymer chips (TopoChips) incorporating 2,176 combinatorially generated micro-topographies. Specific surface topographies exerted a profound impact on bacterial pathogen attachment independent of surface chemistry. A strong correlation between local surface landscape, bacterial attachment and biofilm formation was established using machine learning methods to facilitate analysis of specific surface parameters for predicting attachment. In vitro, lead topographies prevented colonization by motile (Pseudomonas aeruginosa and Proteus mirabilis) and non-motile (Staphylococcus aureus and Acinetobacter baumannii) bacterial pathogens. In a murine foreign body infection model, specific anti-attachment topographies were shown to be refractory to P. aeruginosa colonization.

Putrescine and its metabolic precursor arginine promote biofilm and c-di-GMP synthesis in Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Zhexian Liu ◽  
Sarzana S. Hossain ◽  
Zayda Morales Moreira ◽  
Cara H. Haney
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Immune Responses ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Bacterial Pathogen ◽  
Guanosine Monophosphate ◽  
Genetic Approach ◽  
Chronic Infections ◽  
Host Immune Responses ◽  
Primary Mechanism

Pseudomonas aeruginosa , an opportunistic bacterial pathogen can synthesize and catabolize a number of small cationic molecules known as polyamines. In several clades of bacteria polyamines regulate biofilm formation, a lifestyle-switching process that confers resistance to environmental stress. The polyamine putrescine and its biosynthetic precursors, L-arginine and agmatine, promote biofilm formation in Pseudomonas spp. However, it remains unclear whether the effect is a direct effect of polyamines or through a metabolic derivative. Here we used a genetic approach to demonstrate that putrescine accumulation, either through disruption of the spermidine biosynthesis pathway or the catabolic putrescine aminotransferase pathway, promoted biofilm formation in P. aeruginosa . Consistent with this observation, exogenous putrescine robustly induced biofilm formation in P. aeruginosa that was dependent on putrescine uptake and biosynthesis pathways. Additionally, we show that L-arginine, the biosynthetic precursor of putrescine, also promoted biofilm formation, but via a mechanism independent of putrescine or agmatine conversion. We found that both putrescine and L-arginine induced a significant increase in the intracellular level of bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) (c-di-GMP), a bacterial second messenger widely found in Proteobacteria that upregulates biofilm formation. Collectively these data show that putrescine and its metabolic precursor arginine promote biofilm and c-di-GMP synthesis in P. aeruginosa . Importance: Biofilm formation allows bacteria to physically attach to a surface, confers tolerance to antimicrobial agents, and promotes resistance to host immune responses. As a result, regulation of biofilm is often crucial for bacterial pathogens to establish chronic infections. A primary mechanism of biofilm promotion in bacteria is the molecule c-di-GMP, which promotes biofilm formation. The level of c-di-GMP is tightly regulated by bacterial enzymes. In this study, we found that putrescine, a small molecule ubiquitously found in eukaryotic cells, robustly enhances P. aeruginosa biofilm and c-di-GMP. We propose that P. aeruginosa may sense putrescine as a host-associated signal that triggers a lifestyle switching that favors chronic infection.

scholarly journals Evaluation of Antibiotic Resistance Pattern, Alginate and Biofilm Production in Clinical Isolates of Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Fateme DAVARZANI ◽  
Navid SAIDI ◽  
Saeed BESHARATI ◽  
Horieh SADERI ◽  
Iraj RASOOLI ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Alginate Production ◽  
Opportunistic Bacteria

Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa. Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively. Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were MultidrugResistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates. Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.

scholarly journals Peptide Mix from Olivancillaria hiatula Interferes with Cell-to-Cell Communication in Pseudomonas aeruginosa

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Edward Ntim Gasu ◽  
Hubert Senanu Ahor ◽  
Lawrence Sheringham Borquaye
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Cell Communication ◽  
Microtiter Plate ◽  
Antibiofilm Activity ◽  
Dependent Manner ◽  
Biofilm Inhibition ◽  
Swarming Motility

Bacteria in biofilms are encased in an extracellular polymeric matrix that limits exposure of microbial cells to lethal doses of antimicrobial agents, leading to resistance. In Pseudomonas aeruginosa, biofilm formation is regulated by cell-to-cell communication, called quorum sensing. Quorum sensing facilitates a variety of bacterial physiological functions such as swarming motility and protease, pyoverdine, and pyocyanin productions. Peptide mix from the marine mollusc, Olivancillaria hiatula, has been studied for its antibiofilm activity against Pseudomonas aeruginosa. Microscopy and microtiter plate-based assays were used to evaluate biofilm inhibitory activities. Effect of the peptide mix on quorum sensing-mediated processes was also evaluated. Peptide mix proved to be a good antibiofilm agent, requiring less than 39 μg/mL to inhibit 50% biofilm formation. Micrographs obtained confirmed biofilm inhibition at 1/2 MIC whereas 2.5 mg/mL was required to degrade preformed biofilm. There was a marked attenuation in quorum sensing-mediated phenotypes as well. At 1/2 MIC of peptide, the expression of pyocyanin, pyoverdine, and protease was inhibited by 60%, 72%, and 54%, respectively. Additionally, swarming motility was repressed by peptide in a dose-dependent manner. These results suggest that the peptide mix from Olivancillaria hiatula probably inhibits biofilm formation by interfering with cell-to-cell communication in Pseudomonas aeruginosa.

scholarly journals Lysine Trimethylation of EF-Tu Mimics Platelet-Activating Factor To Initiate Pseudomonas aeruginosa Pneumonia

mBio ◽  
2013 ◽  
Vol 4 (3) ◽  
Author(s):  
Mariette Barbier ◽  
Joshua P. Owings ◽  
Inmaculada Martínez-Ramos ◽  
F. Heath Damron ◽  
Rosa Gomila ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Platelet Activating Factor ◽  
Elongation Factor ◽  
Multidrug Resistant ◽  
Bacterial Attachment ◽  
Point Of View ◽  
Elongation Factor Tu ◽  
Human Pathogens ◽  
Content Type ◽  
Bacterial Surface

ABSTRACTPseudomonas aeruginosais a ubiquitous microorganism and the most common Gram-negative bacterium associated with nosocomial pneumonia, which is a leading cause of mortality among critically ill patients. Although many virulence factors have been identified in this pathogen, little is known about the bacterial components required to initiate infection in the host. Here, we identified a unique trimethyl lysine posttranslational modification of elongation factor Tu as a previously unrecognized bacterial ligand involved in early host colonization byP. aeruginosa. This modification is carried out by a novel methyltransferase, here named elongation factor Tu-modifying enzyme, resulting in a motif that is a structural mimic of the phosphorylcholine present in platelet-activating factor. This novel motif mediates bacterial attachment to airway respiratory cells through platelet-activating factor receptor and is a major virulence factor, expression of which is a prerequisite to pneumonia in a murine model of respiratory infection.IMPORTANCEPhosphorylcholine is an interesting molecule from the microbiological and immunological point of view. It is a crucial epitope for the virulence of many important human pathogens, modulates the host immune response, and is involved in a wide number of processes ranging from allergy to inflammation. Our current work identifies a novel bacterial surface epitope structurally and functionally similar to phosphorylcholine. This novel epitope is crucial for initial colonization of the respiratory tract byPseudomonas aeruginosaand for development of pneumonia. This opens up new targets for the development of novel drugs to preventP. aeruginosapneumonia, which is particularly important given the frequent emergence of multidrug-resistant strains.

scholarly journals A multivariate approach to correlate bacterial surface properties to biofilm formation by lipopolysaccharide mutants of Pseudomonas aeruginosa

2015 ◽  
Vol 127 ◽  
pp. 182-191 ◽  
Author(s):  
Rohit Ruhal ◽  
Henrik Antti ◽  
Olena Rzhepishevska ◽  
Nicolas Boulanger ◽  
David R. Barbero ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Surface Properties ◽  
Biofilm Formation ◽  
Multivariate Approach ◽  
Bacterial Surface

scholarly journals Chicken Juice Enhances Surface Attachment and Biofilm Formation of Campylobacter jejuni

2014 ◽  
Vol 80 (22) ◽  
pp. 7053-7060 ◽  
Author(s):  
Helen L. Brown ◽  
Mark Reuter ◽  
Louise J. Salt ◽  
Kathryn L. Cross ◽  
Roy P. Betts ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Food Chain ◽  
Biofilm Formation ◽  
Cell Attachment ◽  
Bacterial Attachment ◽  
Poultry Meat ◽  
Abiotic Surface ◽  
Surface Attachment ◽  
Aerobic Conditions ◽  
Content Type

ABSTRACTThe bacterial pathogenCampylobacter jejuniis primarily transmitted via the consumption of contaminated foodstuffs, especially poultry meat. In food processing environments,C. jejuniis required to survive a multitude of stresses and requires the use of specific survival mechanisms, such as biofilms. An initial step in biofilm formation is bacterial attachment to a surface. Here, we investigated the effects of a chicken meat exudate (chicken juice) onC. jejunisurface attachment and biofilm formation. Supplementation of brucella broth with ≥5% chicken juice resulted in increased biofilm formation on glass, polystyrene, and stainless steel surfaces with fourC. jejuniisolates and oneC. coliisolate in both microaerobic and aerobic conditions. When incubated with chicken juice,C. jejuniwas both able to grow and form biofilms in static cultures in aerobic conditions. Electron microscopy showed thatC. jejunicells were associated with chicken juice particulates attached to the abiotic surface rather than the surface itself. This suggests that chicken juice contributes toC. jejunibiofilm formation by covering and conditioning the abiotic surface and is a source of nutrients. Chicken juice was able to complement the reduction in biofilm formation of an aflagellated mutant ofC. jejuni, indicating that chicken juice may support food chain transmission of isolates with lowered motility. We provide here a useful model for studying the interaction ofC. jejunibiofilms in food chain-relevant conditions and also show a possible mechanism forC. jejunicell attachment and biofilm initiation on abiotic surfaces within the food chain.

scholarly journals Advanced understanding of prokaryotic biofilm formation using a cost-effective and versatile multi-panel adhesion (mPAD) mount

2022 ◽  
Author(s):  
Stefan Schulze ◽  
Heather Schiller ◽  
Jordan Solomonic ◽  
Orkan Telhan ◽  
Kyle Costa ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Cost Effective ◽  
Flow Chamber ◽  
Culture Conditions ◽  
Multiple Time ◽  
Wild Type ◽  
Surface Attachment ◽  
Flowing Liquid ◽  
Multiple Time Points ◽  
Static Conditions

Most microorganisms exist in biofilms, which comprise aggregates of cells surrounded by an extracellular matrix that provides protection from external stresses. Based on the conditions under which they form, biofilm structures vary in significant ways. For instance, biofilms that develop when microbes are incubated under static conditions differ from those formed when microbes encounter the shear forces of a flowing liquid. Moreover, biofilms develop dynamically over time. Here, we describe a cost-effective, 3D-printed coverslip holder that facilitates surface adhesion assays under a broad range of standing and shaking culture conditions. This multi-panel adhesion (mPAD) mount further allows cultures to be sampled at multiple time points, ensuring consistency and comparability between samples and enabling analyses of the dynamics of biofilm formation. As a proof of principle, using the mPAD mount for shaking, oxic cultures, we confirm previous flow chamber experiments showing that Pseudomonas aeruginosa wild type and a phenazine deletion mutant (Δ phz ) form biofilms with similar structure but reduced density in the mutant strain. Extending this analysis to anoxic conditions, we reveal that microcolony and biofilm formation can only be observed under shaking conditions and are decreased in the Δ phz mutant compared to wild-type cultures, indicating that phenazines are crucial for the formation of biofilms if oxygen as an electron acceptor is unavailable. Furthermore, while the model archaeon Haloferax volcanii does not require archaella for surface attachment under static conditions, we demonstrate that H. volcanii mutants that lack archaella are impaired in early stages of biofilm formation under shaking conditions. Importance: Due to the versatility of the mPAD mount, we anticipate that it will aid the analysis of biofilm formation in a broad range of bacteria and archaea. Thereby, it contributes to answering critical biological questions about the regulatory and structural components of biofilm formation and understanding this process in a wide array of environmental, biotechnological, and medical contexts.

scholarly journals Modulation of Flagellar Rotation in Surface-Attached Bacteria: A Circuit for Rapid Surface-Sensing

2019 ◽  
Author(s):  
Maren Schniederberend ◽  
Jessica F. Johnston ◽  
Emilee Shine ◽  
Cong Shen ◽  
Ruchi Jain ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Second Messenger ◽  
Switching Behavior ◽  
Scaffolding Protein ◽  
Polar Flagellum ◽  
Initial Contact ◽  
Surface Attachment ◽  
Attached Bacteria ◽  
Flagellar Rotation

AbstractAttachment is a necessary first step in bacterial commitment to surface-associated behaviors that include colonization, biofilm formation, and host-directed virulence. The Gram-negative opportunistic pathogen Pseudomonas aeruginosa can initially attach to surfaces via its single polar flagellum. Although many bacteria quickly detach, some become irreversibly attached and express surface-associated structures, such as Type IV pili, and behaviors, including twitching motility and biofilm initiation. P. aeruginosa that lack the GTPase FlhF assemble a randomly placed flagellum that is motile; however, we observed that these mutant bacteria show defects in biofilm formation comparable to those seen for non-motile, aflagellate bacteria. This phenotype was associated with altered behavior of ΔflhF bacteria immediately following surface-attachment. Forward and reverse genetic screens led to the discovery that FlhF interacts with FimV to control flagellar rotation at a surface, and implicated cAMP signaling in this pathway. Although cAMP controls many transcriptional programs in P. aeruginosa, the known targets of this second messenger were not required to modulate flagellar rotation in surface-attached bacteria. Instead, alterations in switching behavior of the motor appear to result from previously undescribed effects of cAMP on switch complex proteins and/or the motor-stators associated with them.Author SummaryAttachment to a surface often triggers programs of gene expression that alter the behavior, virulence and fitness of bacteria. Initial contact is usually mediated by surface exposed adhesins, such as flagella or pili/fimbriae, and there is much interest in how these structures might sense and respond to surface attachment. The human bacterial pathogen Pseudomonas aeruginosa usually contacts surfaces via its polar flagellum, the rotary motor that also powers bacterial swimming. We observed that wild-type bacteria quickly stopped rotating their flagellum after surface attachment, but that a mutant lacking the flagellar-associated protein FlhF did not. Using a combination of genetic approaches, we demonstrated that FlhF interacts with a component of the flagellar rotor (FliG) and with a polar scaffolding protein that positively regulates cAMP production (FimV) to stop flagellar rotation and thereby favor bacterial persistence at a surface. We provide evidence that the second messenger cAMP is the likely signal generated by flagellar-mediated surface attachment and show that cAMP is sufficient to alter the behavior of the flagellar motor.

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