Bacterial Biofilm Development Research Articles

Suspension Flame Spray Construction of Polyimide-Copper Layers for Marine Antifouling Applications

Individual capsule-like polyimide splats have been fabricated by suspension flame spray, and the polyimide splat exhibits hollow structure with an inner pore and a tiny hole on its top surface. Enwrapping of 200-1000-nm copper particles inside the splats is accomplished during the deposition for constrained release of copper for antifouling performances. Antifouling testing of the coatings by 24-h exposure to Escherichia coli-containing artificial seawater shows that the Cu-doped splat already prohibits effectively attachment of the bacteria. The prohibited adhesion of bacteria obviously impedes formation and further development of bacterial biofilm. This capsulated splat with releasing and loading of copper biocides results in dual-functional structures bearing both release-killing and contact-killing mechanisms. The suspension flame spray route and the encapsulated structure of the polyimide-Cu coatings would open a new window for designing and constructing marine antifouling layers for long-term applications.

Complete genome sequence of Citrobacter werkmanii strain BF-6 isolated from industrial putrefaction

BackgroundIn our previous study, Citrobacter werkmanii BF-6 was isolated from an industrial spoilage sample and demonstrated an excellent ability to form biofilms, which could be affected by various environmental factors. However, the genome sequence of this organism has not been reported so far.ResultsWe report the complete genome sequence of C. werkmanii BF-6 together with the description of the genome features and its annotation. The size of the complete chromosome is 4,929,789 bp with an average coverage of 137×. The chromosome exhibits an average G + C content of 52.0%, and encodes 4570 protein coding genes, 84 tRNA genes, 25 rRNA operons, 3 microsatellite sequences and 34 minisatellite sequences. A previously unknown circular plasmid designated as pCW001 was also found with a length of 212,549 bp and a G + C content of 48.2%. 73.5%, 75.6% and 92.6% of the protein coding genes could be assigned to GO Ontology, KEGG Pathway, and COG (Clusters of Orthologous Groups) categories respectively. C. werkmanii BF-6 and C. werkmanii NRBC 105721 exhibited the closest evolutionary relationships based on 16S ribosomal RNA and core-pan genome assay. Furthermore, C. werkmanii BF-6 exhibits typical bacterial biofilm formation and development. In the RT-PCR experiments, we found that a great number of biofilm related genes, such as bsmA, bssR, bssS, hmsP, tabA, csgA, csgB, csgC, csgD, csgE, and csgG, were involved in C. werkmanii BF-6 biofilm formation.ConclusionsThis is the first complete genome of C. werkmanii. Our work highlights the potential genetic mechanisms involved in biofilm formation and paves a way for further application of C. werkmanii in biofilms research.

C-di-AMP regulates bacterial biofilm formation

Bacterial biofilm plays an important role in persistent microbial infection. Delineation of the formation and development of bacterial biofilm would provide a promising strategy to treat recalcitrant infection. c-di-AMP (Cyclic diadenosine monophosphate) is a recently identified second messenger of bacteria and involved in plethora of bacterial activities, including cell growth, cell wall homeostasis, biofilm formation and microbial pathogenicity. Here we review the recent literature pertinent to the role and molecular mechanisms of c-di-AMP in regulating biofilm formation of bacteria. The potential application of c-di-AMP and its related proteins in the development of novel antimicrobial therapeutics has also been discussed.

Chemical agents modulating bacterial biofilm formation and development

Biofilm is a bacterial lifestyle ubiquitously in natural environments. Bacterial biofilm leads to drug resistance, a main reason why many infectious diseases are difficult to control. Due to the prominent points of biofilms implicated in infectious disease and the spread of multi-drug resistance, it is urgent to discover new antibacterial agents that can regulate biofilm formation and development. This review introduces chemical agents that could modulate bacterial biofilm formation and development.

Potential Role of Curcumin Against Biofilm-Producing Organisms on the Skin: A Review.

Turmeric root (Curcuma longa) is predominantly used as a spice, but has also long been known to possess antimicrobial, analgesic, antiinflammatory, and anticancer properties. One predominant group of active compounds in turmeric are curcuminoids, namely bright yellow-pigmented curcumin. While modern science has yet to fully investigate the therapeutic claims of turmeric and its derivatives, results have proven promising in decreasing pain and inflammation in arthritis, improving insulin sensitivity in diabetes, and even curing a variety of infections. The purpose of this review is to discuss the potential for curcumin as an agent against microbial infections, with a special focus on the skin and in the development of bacterial biofilms. Curcumin has demonstrated bactericidal efficacy against a variety of infections when administered with antibiotics in several clinical studies, with consistent antimicrobial activity demonstrated in vitro, as well as in urinary tract infections, gingival infections, and chronic wound infections. Hypothesized mechanisms of action include curcumin's ability to perturb bacterial membranes, disturb protofillament assembly, and even impair bacterial virulence factors. Further investigation is needed to fully understand which organisms are most susceptible to the effects of curcumin and how curcumin can be implemented in dermatology to treat skin conditions such as chronic wounds and acne vulgaris. Copyright © 2017 John Wiley & Sons, Ltd.

A Low-Molecular-Weight Alginate Oligosaccharide Disrupts Pseudomonal Microcolony Formation and Enhances Antibiotic Effectiveness

In chronic respiratory disease, the formation of dense, 3-dimensional "microcolonies" by Pseudomonas aeruginosa within the airway plays an important role in contributing to resistance to treatment. An in vitro biofilm model of pseudomonal microcolony formation using artificial-sputum (AS) medium was established to study the effects of low-molecular-weight alginate oligomers (OligoG CF-5/20) on pseudomonal growth, microcolony formation, and the efficacy of colistin. The studies employed clinical cystic fibrosis (CF) isolates (n = 3) and reference nonmucoid and mucoid multidrug-resistant (MDR) CF isolates (n = 7). Bacterial growth and biofilm development and disruption were studied using cell viability assays and image analysis with scanning electron and confocal laser scanning microscopy. Pseudomonal growth in AS medium was associated with increased ATP production (P < 0.05) and the formation (at 48 h) of discrete (>10-μm) microcolonies. In conventional growth medium, colistin retained an ability to inhibit growth of planktonic bacteria, although the MIC was increased (0.1 to 0.4 μg/ml) in AS medium compared to Mueller-Hinton (MH) medium. In contrast, in an established-biofilm model in AS medium, the efficacy of colistin was decreased. OligoG CF-5/20 (≥2%) treatment, however, induced dose-dependent biofilm disruption (P < 0.05) and led to colistin retaining its antimicrobial activity (P < 0.05). While circular dichroism indicated that OligoG CF-5/20 did not change the orientation of the alginate carboxyl groups, mass spectrometry demonstrated that the oligomers induced dose-dependent (>0.2%; P < 0.05) reductions in pseudomonal quorum-sensing signaling. These findings reinforce the potential clinical significance of microcolony formation in the CF lung and highlight a novel approach to treat MDR pseudomonal infections.

Involvement of Two-Component Signaling on Bacterial Motility and Biofilm Development.

Two-component signaling is a specialized mechanism that bacteria use to respond to changes in their environment. Nonpathogenic strains of Escherichia coli K-12 harbor 30 histidine kinases and 32 response regulators, which form a network of regulation that integrates many other global regulators that do not follow the two-component signaling mechanism, as well as signals from central metabolism. The output of this network is a multitude of phenotypic changes in response to changes in the environment. Among these phenotypic changes, many two-component systems control motility and/or the formation of biofilm, sessile communities of bacteria that form on surfaces. Motility is the first reversible attachment phase of biofilm development, followed by a so-called swim or stick switch toward surface organelles that aid in the subsequent phases. In the mature biofilm, motility heterogeneity is generated by a combination of evolutionary and gene regulatory events.

Development of non-pathogenic bacterial biofilms on the surface of stainless steel which are inhibitory to Salmonella enterica

Non-pathogenic bacterial biofilms were developed on the surface of stainless steel possessing desiccation tolerance and antimicrobial activity against Salmonella enterica. Three bacteria exhibiting strong antimicrobial activities against S. enterica were isolated from various soils, foods, and food-contact surfaces. Isolates were identified as Pseudomonas extremorientalis (strain Lettuce-28), Paenibacillus peoriae (strain Lettuce-7), and Streptomyces cirratus (strain Geumsan-207). These bacteria grew rapidly and formed biofilms within 24 h on the surface of stainless steel coupons (SSCs) immersed in laboratory media (tryptic soy broth or Bennet's broth) at 25 °C. Cells in biofilms had enhanced tolerance to desiccation (exposure to 43% atmospheric relative humidity [RH]) and retained antimicrobial activity against S. enterica. Populations of S. enterica deposited on SSCs containing biofilm formed by Ps. extremorientalis strain Lettuce-28, for example, decreased by > 2.5 log CFU/coupon within 24 h at 25 °C and 43% RH, while the number of cells inoculated on SSCs lacking biofilm decreased by 1.5 log CFU/coupon. Antimicrobial activities of the three antagonistic bacteria against S. enterica persisted in desiccated biofilms. This study provides insights to developing strategies to inactivate Salmonella and perhaps other foodborne pathogens on abiotic surfaces using non-pathogenic antagonistic bacteria.

SUPRESSION OF BIOFILMS OF OPPORTUNISTIC BACTERIA IN URINARY CATHETERS

Aim. Study regularities of development of bacterial biofilms in opportunistic bacteria in urinary catheters, as well as a possibility of their suppression by an officinal preparation of plant origin - Kanefron and nitrofuran class preparation - Furamag. Materials and methods. Escherichia coli Ml7 and Staphylococcus aureus 193 cultures were cultivated as biofilms on an inner surface of Foley latex catheter. Effect of Kanefron and Furamag on the ability of these strain to form biofilms was evaluated, as well as suppression of already developed biofilm of E. coli M17 and S. aureus 193 on urine catheters. Determination of bactericidal effect of preparations during incubation of microorganisms on the surface of urine caterers was carried out by Koch method. Morphologic and i ultrastructure changes in bacterial cells and biofilms were studied by transmission and scanning j electron microscopy. Results. A pronounced bactericidal effect of Kanefron and Furamag on the formed bacterial biofilms was detected. Inhibiting effect on growth and development of biofilms of the strains was noted. Destructive changes in cells and biofilms during the effect of the studied preparations are shown on electron microscopy level. Conclusion. The detected bactericidal effect of officinal preparation of plant origin - Kanefron and nitrofuran class preparation - Furamag on opportunistic bacteria on Foley urine catheters allows not only to suppress biofilm formation process of E. coli M17 и S. aureus 193 compared with classic antiseptic methods, but also effectively destroy already formed biofilms that must prevent development of catheter-associated infections and result in enhancement of recuperation of patients with diseases of the urinary tract.

Enzyme-mimicking polymer brush-functionalized surface for combating biomaterial-associated infections

Biomaterial-associated infections critically compromise the functionality and performance of the medical devices, and pose a serious threat to human healthcare. Recently, natural DNase enzyme has been recognized as a potent material to prevent bacterial adhesion and biofilm formation. However, the vulnerability of DNase dramatically limits its long-term performance in antibacterial applications. In this work, DNase-mimicking polymer brushes were constructed to mimic the DNA-cleavage activity as well as the macromolecular scaffold of the natural DNase. The bacteria repellent efficacy of DNase-mimicking polymer brush-functionalized surface was comparable to that of the DNase-functionalized surface. More importantly, due to their inherent stability, DNase-mimicking polymer brushes presented the much better performance in inhibiting bacterial biofilm development for prolonged periods of time, as compared to the natural DNase. The as-developed DNase-mimicking polymer brush-functionalized surface presents a promising approach to combat biomaterial-associated infections.

Biofilm vs. Planktonic Lifestyle: Consequences for Pesticide 2,4-D Metabolism by Cupriavidus necator JMP134.

The development of bacterial biofilms in natural environments may alter important functions, such as pollutant bioremediation by modifying both the degraders' physiology and/or interactions within the matrix. The present study focuses on the influence of biofilm formation on the metabolism of a pesticide, 2,4-dichlorophenoxyacetic acid (2,4-D), by Cupriavidus necator JMP134. Pure cultures were established in a liquid medium with 2,4-D as a sole carbon source with or without sand grains for 10 days. Bacterial numbers and 2,4-D concentrations in solution were followed by spectrophotometry, the respiration rate by gas chromatography and the surface colonization by electron microscopy. In addition, isotopic techniques coupled with Fatty Acid Methyl Ester (FAME) profiling were used to determine possible metabolic changes. After only 3 days, approximately 80% of the cells were attached to the sand grains and microscopy images showed that the porous medium was totally clogged by the development of a biofilm. After 10 days, there was 25% less 2,4-D in the solution in samples with sand than in control samples. This difference was due to (1) a higher (+8%) mineralization of 2,4-D by sessile bacteria and (2) a retention (15%) of 2,4-D in the biofilm matrix. Besides, the amount of carbohydrates, presumably constituting the biofilm polysaccharides, increased by 63%. Compound-specific isotope analysis revealed that the FAME isotopic signature was less affected by the biofilm lifestyle than was the FAME composition. These results suggest that sessile bacteria differ more in their anabolism than in their catabolism compared to their planktonic counterparts. This study stresses the importance of considering interactions between microorganisms and their habitat when studying pollutant dynamics in porous media.

Design of a dynamic biofilm imaging cell for white-light interferometric microscopy

In microbiology research, there is a strong need for next-generation imaging and sensing instrumentation that will enable minimally invasive and label-free investigation of soft, hydrated structures, such as in bacterial biofilms. White-light interferometry (WLI) can provide high-resolution images of surface topology without the use of fluorescent labels but is not typically used to image biofilms because there is insufficient refractive index contrast to induce reflection from the biofilm’s interface. The soft structure and water-like bulk properties of hydrated biofilms make them difficult to characterize in situ, especially in a nondestructive manner. We build on our prior description of static biofilm imaging and describe the design of a dynamic growth flow cell that enables monitoring of the thickness and topology of live biofilms over time using a WLI microscope. The microfluidic system is designed to grow biofilms in dynamic conditions and to create a reflective interface on the surface while minimizing disruption of fragile structures. The imaging cell was also designed to accommodate limitations imposed by the depth of focus of the microscope’s objective lens. Example images of live biofilm samples are shown to illustrate the ability of the flow cell and WLI instrument to (1) support bacterial growth and biofilm development, (2) image biofilm structure that reflects growth in flow conditions, and (3) monitor biofilm development over time nondestructively. In future work, the apparatus described here will enable surface metrology measurements (roughness, surface area, etc.) of biofilms and may be used to observe changes in biofilm structure in response to changes in environmental conditions (e.g., flow velocity, availability of nutrients, and presence of biocides). This development will open opportunities for the use of WLI in bioimaging.

Take my breath away.

A lack of oxygen activates a pathway that causes the bacterial cell wall to break down, which, in turn, aids bacterial biofilm development.

Fatty acid DSF binds and allosterically activates histidine kinase RpfC of phytopathogenic bacterium Xanthomonas campestris pv. campestris to regulate quorum-sensing and virulence.

As well as their importance to nutrition, fatty acids (FA) represent a unique group of quorum sensing chemicals that modulate the behavior of bacterial population in virulence. However, the way in which full-length, membrane-bound receptors biochemically detect FA remains unclear. Here, we provide genetic, enzymological and biophysical evidences to demonstrate that in the phytopathogenic bacterium Xanthomonas campestris pv. campestris, a medium-chain FA diffusible signal factor (DSF) binds directly to the N-terminal, 22 amino acid-length sensor region of a receptor histidine kinase (HK), RpfC. The binding event remarkably activates RpfC autokinase activity by causing an allosteric change associated with the dimerization and histidine phosphotransfer (DHp) and catalytic ATP-binding (CA) domains. Six residues were found essential for sensing DSF, especially those located in the region adjoining to the inner membrane of cells. Disrupting direct DSF-RpfC interaction caused deficiency in bacterial virulence and biofilm development. In addition, two amino acids within the juxtamembrane domain of RpfC, Leu172 and Ala178, are involved in the autoinhibition of the RpfC kinase activity. Replacements of them caused constitutive activation of RpfC-mediated signaling regardless of DSF stimulation. Therefore, our results revealed a biochemical mechanism whereby FA activates bacterial HK in an allosteric manner, which will assist in future studies on the specificity of FA-HK recognition during bacterial virulence regulation and cell-cell communication.

Air pollution alters Staphylococcus aureus and Streptococcus pneumoniae biofilms, antibiotic tolerance and colonisation.

SummaryAir pollution is the world's largest single environmental health risk (WHO). Particulate matter such as black carbon is one of the main components of air pollution. The effects of particulate matter on human health are well established however the effects on bacteria, organisms central to ecosystems in humans and in the natural environment, are poorly understood. We report here for the first time that black carbon drastically changes the development of bacterial biofilms, key aspects of bacterial colonisation and survival. Our data show that exposure to black carbon induces structural, compositional and functional changes in the biofilms of both S. pneumoniae and S. aureus. Importantly, the tolerance of the biofilms to multiple antibiotics and proteolytic degradation is significantly affected. Additionally, our results show that black carbon impacts bacterial colonisation in vivo. In a mouse nasopharyngeal colonisation model, black carbon caused S. pneumoniae to spread from the nasopharynx to the lungs, which is essential for subsequent infection. Therefore our study highlights that air pollution has a significant effect on bacteria that has been largely overlooked. Consequently these findings have important implications concerning the impact of air pollution on human health and bacterial ecosystems worldwide.

A New Method for Qualitative Multi-scale Analysis of Bacterial Biofilms on Filamentous Fungal Colonies Using Confocal and Electron Microscopy.

Bacterial biofilms frequently form on fungal surfaces and can be involved in numerous bacterial-fungal interaction processes, such as metabolic cooperation, competition, or predation. The study of biofilms is important in many biological fields, including environmental science, food production, and medicine. However, few studies have focused on such bacterial biofilms, partially due to the difficulty of investigating them. Most of the methods for qualitative and quantitative biofilm analyses described in the literature are only suitable for biofilms forming on abiotic surfaces or on homogeneous and thin biotic surfaces, such as a monolayer of epithelial cells.While laser scanning confocal microscopy (LSCM) is often used to analyze in situ and in vivo biofilms, this technology becomes very challenging when applied to bacterial biofilms on fungal hyphae, due to the thickness and the three dimensions of the hyphal networks. To overcome this shortcoming, we developed a protocol combining microscopy with a method to limit the accumulation of hyphal layers in fungal colonies. Using this method, we were able to investigate the development of bacterial biofilms on fungal hyphae at multiple scales using both LSCM and scanning electron microscopy (SEM). This report describes the protocol, including microorganism cultures, bacterial biofilm formation conditions, biofilm staining, and LSCM and SEM visualizations.

ВЛИЯНИЕ ЭКСТРАКТОВ РАСТЕНИЙ И ОТДЕЛЬНЫХ МЕТАБОЛИТОВ НА ОБРАЗОВАНИЕ БИОПЛЕНОК (ОБЗОР)

The review considered various regulators of development of bacterial biofilms. Special attention is paid to essential oils, vegetable extracts, their fractions and specific compounds of medicinal, food and forage plants. Uncovered a number of their impact mechanisms on the collective behavior of microorganisms. Substances produced by plants can provide not only a direct toxic effect on the bacterial cells, but also serve regulating of gene expression of antibiotic resistance genes and their biosynthesis, as well as a wide range of genes being activated when switching from free existence to the attached living. Considered by the activity of plant extracts and metabolites are distributed not only on gram and gram bacteria, but also on other microorganisms, including yeast, that extends the capabilities of their practical application. Synergistic effects metabolites of plants with antibiotics and their ability to effectively block quorum sensing bacteria and their adhesion, allow you to deal with plant extracts and isolated compounds of plant origin as promising to combat infectious processes caused by the ability of bacteria to form biofilms. By and large, in any of the known higher and lower plant may contain substances of antibacterial actions violating the strategy of collective behaviour of microorganisms and inhibit pathogenic bacteria colonization of tissues and cells of plant. Bactericidal, bacteriostatic and anti biofilm effects, can differ significantly even in the case of compounds of similar chemical nature and one the same substance can simultaneously serve to different regulation mechanisms.

0702 Evaluation of modified stainless steel surfaces targeted to reduce biofilm formation by common dairy related sporeformers

Development of bacterial biofilms on stainless steel (SS) surface of dairy equipment such as plate heat exchangers pose a great threat to the quality of milk and other dairy products, as the biofilm-embedded bacteria can survive thermal processing to a greater extent. Many of these are sporeformers that also form heat-resistant spores, leading to a long-term persistent contamination. Biofilms also offer cleaning challenges, as they are generally resistant to regular cleaning protocols. The main objective of this study was to evaluate different surface modifications (AMC 18, Durasan, Lindgren, and Magnaplate) of stainless steel for their resistance to biofilm formation. It was hypothesized that these coated surfaces would promote a lower deposit build-up and bacterial adhesion. Challenge studies, using vegetative cells of common dairy-related aerobic sporeformers, namely Geobacillus stearothermophilus (ATCC 15952), Bacillus licheniformis (ATCC 6634), and Bacillus sporothermodurans (DSM 10599), were conducted to study the biofilm formation on the modified and native SS coupons under static conditions. Standard enumeration techniques were used to culture biofilm-embedded bacteria. The adherence of these organisms was observed to be influenced by surface energy and hydrophobicity but exhibited no relationship with surface roughness. Statistical analysis of the number of adhered cells of G. stearothermophilus to different native and modified SS surfaces, after 72 h of incubation, revealed significant differences in counts. Lindgren was observed to be most resistant to bacterial attachment (average 3.15 log cfu/cm2), in comparison to the native SS surface that recorded a higher average bacterial adhesion of 5.11 logs. Similar results were obtained with B. licheniformis and B. sporothermodurans, the latter showing least attachment. Scanning electron microscopy provided the visual evidence of the extent of biofilm development and bacterial attachment on the surface of modified and native SS surfaces. In conclusion, Lindgren coating, being the most resistant to biofilm development, could potentially help in reducing the bacterial cross-contamination of milk and dairy products during processing.

Copolymer Brushes with Temperature-Triggered, Reversibly Switchable Bactericidal and Antifouling Properties for Biomaterial Surfaces.

The adherence of bacteria and the formation of biofilm on implants is a serious problem that often leads to implant failure. A series of antimicrobial coatings have been constructed to resist bacterial adherence or to kill bacteria through contact with or release of antibacterial agents. The accumulation of dead bacteria facilitates further bacterial contamination and biofilm development. Herein, we have designed and constructed a novel, reversibly switchable bactericidal and antifouling surface through surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization to combine thermally responsive N-isopropylacrylamide (NIPAAm) and bactericidal quaternary ammonium salts (2-(dimethylamino)-ethyl methacrylate (DMAEMA+)). Measurements of spectroscopic ellipsometry and water contact angle and X-ray photoelectron spectroscopy were used to examine the process of the surface functionalization. The temperature-responsive P(DMAEMA+-co-NIPAAm) copolymer coating can switch by phase transition between a hydrophobic capturing surface at high temperatures and a relatively hydrophilic antifouling surface at lower temperatures. The quaternary ammonium salts of PDMAEMA+ displayed bactericidal efficiency against both Escherichia coli and Staphylococcus aureus. The functionalized surface could efficiently prevent bovine serum albumin adsorption and had good biocompatibility against human lens epithelial cells.

Evaluation of modified stainless steel surfaces targeted to reduce biofilm formation by common milk sporeformers.

The development of bacterial biofilms on stainless steel (SS) surfaces poses a great threat to the quality of milk and other dairy products as the biofilm-embedded bacteria can survive thermal processing. Established biofilms offer cleaning challenges because they are resistant to most of the regular cleaning protocols. Sporeforming thermoduric organisms entrapped within biofilm matrix can also form heat-resistant spores, and may result in a long-term persistent contamination. The main objective of this study was to evaluate the efficacy of different nonfouling coatings [AMC 18 (Advanced Materials Components Express, Lemont, PA), Dursan (SilcoTek Corporation, Bellefonte, PA), Ni-P-polytetrafluoroethylene (PTFE, Avtec Finishing Systems, New Hope, MN), and Lectrofluor 641 (General Magnaplate Corporation, Linden, NJ)] on SS plate heat exchanger surfaces, to resist the formation of bacterial biofilms. It was hypothesized that modified SS surfaces would promote a lesser amount of deposit buildup and bacterial adhesion as compared with the native SS surface. Vegetative cells of aerobic sporeformers, Geobacillus stearothermophilus (ATCC 15952), Bacillus licheniformis (ATCC 6634), and Bacillus sporothermodurans (DSM 10599), were used to study biofilm development on the modified and native SS surfaces. The adherence of these organisms, though influenced by surface energy and hydrophobicity, exhibited no apparent relation with surface roughness. The Ni-P-PTFE coating exhibited the least bacterial attachment and milk solid deposition, and hence, was the most resistant to biofilm formation. Scanning electron microscopy, which was used to visualize the extent of biofilm formation on modified and native SS surfaces, also revealed lower bacterial attachment on the Ni-P-PTFE as compared with the native SS surface. This study thus provides evidence of reduced biofilm formation on the modified SS surfaces.