scholarly journals The Application of Impedance Spectroscopy for Pseudomonas Biofilm Monitoring during Phage Infection

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 407 ◽  
Author(s):  
Grzegorz Guła ◽  
Paulina Szymanowska ◽  
Tomasz Piasecki ◽  
Sylwia Góras ◽  
Teodor Gotszalk ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Bacterial Resistance ◽  
Early Stage ◽  
Bacterial Biofilm ◽  
Phage Infection ◽  
Matrix Composition ◽  
Bacterial Cells ◽  
Planktonic Culture ◽  
Biofilm Growth ◽  
Biofilm Development

Bacterial biofilm prevention and eradication are common treatment problems, hence there is a need for advanced and precise experimental methods for its monitoring. Bacterial resistance to antibiotics has resulted in an interest in using a natural bacterial enemy—bacteriophages. In this study, we present the application of quartz tuning forks (QTF) as impedance sensors to determine in real-time the direct changes in Pseudomonas aeruginosa PAO1 biofilm growth dynamics during Pseudomonas phage LUZ 19 treatment at different multiplicities of infection (MOI). The impedance of the electric equivalent circuit (EEC) allowed us to measure the series resistance (Rs) corresponding to the growth-medium resistance (planktonic culture changes) and the conductance (G) corresponding to the level of QTF sensor surface coverage by bacterial cells and the extracellular polymer structure (EPS) matrix. It was shown that phage impacts on sessile cells (G dynamics) was very similar in the 10-day biofilm development regardless of applied MOI (0.1, 1 or 10). The application of phages at an early stage (at the sixth h) and on three-day biofilm caused a significant slowdown in biofilm dynamics, whereas the two-day biofilm turned out to be insensitive to phage infection. We observed an inhibitory effect of phage infection on the planktonic culture (Rs dynamics) regardless of the MOI applied and the time point of infection. Moreover, the Rs parameter made it possible to detect PAO1 population regrowth at the latest time points of incubation. The number of phage-insensitive forms reached the level of untreated culture at around the sixth day of infection. We conclude that the proposed impedance spectroscopy technique can be used to measure the physiological changes in the biofilm matrix composition, as well as the condition of planktonic cultures in order to evaluate the activity of anti-biofilm compounds.

Bifunctional Composites for Biofilms Modulation on Cervical Restorations

2021 ◽  
pp. 002203452110181
Author(s):  
A.A. Balhaddad ◽  
I.M. Garcia ◽  
L. Mokeem ◽  
M.S. Ibrahim ◽  
F.M. Collares ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angles ◽  
Bacterial Biofilm ◽  
Dental Composite ◽  
Log P ◽  
Rrna Gene ◽  
Cervical Lesions ◽  
Biofilm Growth ◽  
Biofilm Development

Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque control, enhanced biofilm accumulation, and cause gingival irritation. A potential material to restore such lesions should combine agents that interfere with bacterial biofilm development and respond to acidic conditions. Here, we explore the use of new bioresponsive bifunctional dental composites against mature microcosm biofilms derived from subgingival plaque samples. The designed formulations contain 2 bioactive agents: dimethylaminohexadecyl methacrylate (DMAHDM) at 3 to 5 wt.% and 20 wt.% nanosized amorphous calcium phosphate (NACP) in a base resin. Composites with no DMAHDM and NACP were used as controls. The newly formulated 5% DMAHDM–20% NACP composite was analyzed by micro-Raman spectroscopy and transmission electron microscopy. The wettability and surface-free energy were also assessed. The inhibitory effect on the in vitro biofilm growth and the 16S rRNA gene sequencing of survival bacterial colonies derived from the composites were analyzed. Whole-biofilm metabolic activity, polysaccharide production, and live/dead images of the biofilm grown over the composites complement the microbiological assays. Overall, the designed formulations had higher contact angles with water and lower surface-free energy compared to the commercial control. The DMAHDM-NACP composites significantly inhibited the growth of total microorganisms, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum by 3 to 5-log ( P < 0.001). For the colony isolates from control composites, the composition was typically dominated by the genera Veillonella, Fusobacterium, Streptococcus, Eikenella, and Leptotrichia, while Fusobacterium and Veillonella dominated the 5% DMAHDM–20% NACP composites. The DMAHDM-NACP composites contributed to over 80% of reduction in metabolic and polysaccharide activity. The suppression effect on plaque biofilms suggested that DMAHDM-NACP composites might be used as a bioactive material for cervical restorations. These results may propose an exciting path to prevent biofilm growth and improve dental composite restorations’ life span.

Bioinspired surfaces to delay biofilm formation: different surfaces with different mechanisms

2020 ◽  
Author(s):  
Jinju Chen
Keyword(s):  
Contact Angle ◽  
Biofilm Formation ◽  
Early Stage ◽  
Contact Angle Hysteresis ◽  
Antibacterial Properties ◽  
Hierarchical Structures ◽  
Bacterial Cells ◽  
Biofilm Growth ◽  
Porous Surfaces ◽  
Rose Petal

&lt;p&gt;Biofilm associated infections are the fourth leading cause of death worldwide, within the U.S. about 2 million annual cases lead to more than $5 billion USD in added medical costs per annum. Therefore, it is important to control biofilm growth and reduce the instances of infections.&amp;#160; Physical strategies, in particular the use of rationally designed surface topographies or surface energies, have present us with an interesting approach to prevent bacterial adherence and biofilm growth without the requirement for antimicrobials.&lt;/p&gt; &lt;p&gt;A variety of natural surfaces exhibit antibacterial properties. Examples of such surfaces include rose petals with hierarchical structures and Nepenthes pitcher plants with slippery liquid-infused porous surfaces. &amp;#160;&lt;/p&gt; &lt;p&gt;In this study, we fabricated different &amp;#160;biomimetic surfaces (rose-petal surfaces and slippery liquid-infused porous surfaces). &amp;#160;&amp;#160;We have demonstrated that rose-petal surface can delay early stage P. aeruginosa and S. epidermidis biofilms formation (2 days) by about 70% and control&amp;#160; biofilm &amp;#160;formation according to surface structures.&amp;#160; The mechanisms of hierarchical structures &amp;#160;of rose-petal influence biofilm formation are two folds: 1) Papillae microstructure block &amp;#160;the bacterial clusters in between the valleys, limiting the potential for cell-cell communication via fibrous networks, thereby resulting in impaired biofilm growth. 2) The secondary structure (nano-folds) on microstructures can align bacterial cells within the constrained grooves, thereby delaying cell clusters formation during short term growth of biofilm.&lt;/p&gt; &lt;p&gt;While, the slippery liquid-infused porous surface(s) can prevent over 90% P. aeruginosa and S. epidermidis biofilms formation for a duration of 6 days.&amp;#160; These are mainly attributed to their high contact angle and extreme low contact angle hysteresis.&lt;/p&gt;

scholarly journals Extracellular Electron Transfer Powers Enterococcus faecalis Biofilm Metabolism

2017 ◽  
Author(s):  
Damien Keogh ◽  
Ling Ning Lam ◽  
Lucinda E. Doyle ◽  
Artur Matysik ◽  
Shruti Pavagadhi ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Enterococcus Faecalis ◽  
Bacterial Biofilm ◽  
Extracellular Electron Transfer ◽  
Bacterial Cells ◽  
Free Living ◽  
Biofilm Growth ◽  
Metabolic Versatility ◽  
Tract Infections ◽  
Biofilm Matrix

AbstractEnterococci are important human commensals and significant opportunistic pathogens associated with endocarditis, urinary tract infections, wound and surgical site infections, and medical device associated infections. These infections often become chronic upon the formation of biofilm. The biofilm matrix establishes properties that distinguish this state from free-living bacterial cells and increase tolerance to antimicrobial interventions. The metabolic versatility of the Enterococci is reflected in the diversity and complexity of environments and communities in which they thrive. Understanding metabolic factors governing colonization and persistence in different host niches can reveal factors influencing the transition from commensal to opportunistic pathogen. Here, we report a new form of iron-dependent metabolism for Enterococcus faecalis where, in the absence of heme, respiration components can be utilised for extracellular electron transfer (EET). Iron augments E. faecalis biofilm growth and generates alterations in biofilm matrix, cell spatial distribution, and biofilm matrix properties. We identify the genes involved in iron-augmented biofilm growth and show that it occurs by promoting EET to iron within biofilm.SignificanceBacterial metabolic versatility is often key in dictating the outcome of host-pathogen interactions, yet determinants of metabolic shifts are difficult to resolve. The bacterial biofilm matrix provides the structural and functional support that distinguishes this state from free-living bacterial cells. Here, we show that the biofilm matrix provides access to resources necessary for metabolism and growth which are otherwise inaccessible in the planktonic state. Our data shows that in the absence of heme, components of Enterococcus faecalis respiration (l-lactate dehydrogenase and acetaldehyde dehydrogenase) may function as initiators of EET through the cytoplasmic membrane quinone pool and utilize matrix-associated iron to carry out EET. The presence of iron resources within the biofilm matrix leads to enhanced biofilm growth.

scholarly journals Bacterial Biofilm Growth on Various Dental Stabilization Systems for Avulsed and Luxated Teeth

2021 ◽  
Vol 11 (19) ◽  
pp. 8982
Author(s):  
Mahmoud Mona ◽  
Clay Walker ◽  
Luciana M. Shaddox ◽  
Roberta Pileggi
Keyword(s):  
Bacterial Growth ◽  
Healing Process ◽  
Fluorescent Microscopy ◽  
Critical Factor ◽  
Bacterial Biofilm ◽  
Niti Wire ◽  
Biofilm Growth ◽  
Anterior Teeth ◽  
Biofilm Development ◽  
Post Hoc

With the increased incidence of traumatic injuries and the advanced understanding of the periodontal and alveolar healing process, teeth splinting has become a common practice for stabilizing traumatized teeth. Consequently, several splinting materials and techniques have been introduced in the past few years. Despite the detrimental role of bacterial biofilm on healing, the level of biofilm development on these material surfaces has not been well investigated. Bacterial biofilms are severely detrimental for periodontal healing of avulsed and luxated teeth. Thus, biofilm growth becomes a critical factor in selecting the material of choice for dental splints. In this study, we aim to assess the level of oral biofilm growth on four different splinting systems: Ribbond©, orthodontic NiTi wire, monofilament fishing line, and Titanium Trauma Splint. A total of 72 extracted anterior teeth were divided into four groups. We splinted six rows of three teeth each per group. The teeth selected were caries-free and periodontitis-free at the time of extraction. To assess biofilm growth, a supragingival dental plaque sample was cultured and directly inoculated into all groups. After 7 days, bacterial growth was quantified by live/dead fluorescent microscopy assay and colony forming unit counts (CFU). Using one-way ANOVA and Bonferroni’s post hoc tests, we demonstrated that all splint systems allowed for bacterial growth. However, the Titanium Trauma Splint (TTS) allowed for the least amount of biofilm growth compared to other splint systems.

scholarly journals Mat fimbriae promote biofilm formation by meningitis-associated Escherichia coli

Microbiology ◽  
2010 ◽  
Vol 156 (8) ◽  
pp. 2408-2417 ◽  
Author(s):  
Timo A. Lehti ◽  
Philippe Bauchart ◽  
Johanna Heikkinen ◽  
Jörg Hacker ◽  
Timo K. Korhonen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Early Stage ◽  
Surface Expression ◽  
Growth Media ◽  
Biofilm Growth ◽  
Abiotic Surfaces ◽  
K 12 ◽  
Biofilm Development

The mat (or ecp) fimbrial operon is ubiquitous and conserved in Escherichia coli, but its functions remain poorly described. In routine growth media newborn meningitis isolates of E. coli express the meningitis-associated and temperature-regulated (Mat) fimbria, also termed E. coli common pilus (ECP), at 20 °C, and here we show that the six-gene (matABCDEF)-encoded Mat fimbria is needed for temperature-dependent biofilm formation on abiotic surfaces. The matBCDEF deletion mutant of meningitis E. coli IHE 3034 was defective in an early stage of biofilm development and consequently unable to establish a detectable biofilm, contrasting with IHE 3034 derivatives deleted for flagella, type 1 fimbriae or S-fimbriae, which retained the wild-type biofilm phenotype. Furthermore, induced production of Mat fimbriae from expression plasmids enabled biofilm-deficient E. coli K-12 cells to form biofilm at 20 °C. No biofilm was detected with IHE 3034 or MG1655 strains grown at 37 °C. The surface expression of Mat fimbriae and the frequency of Mat-positive cells in the IHE 3034 population from 20 °C were high and remained unaltered during the transition from planktonic to biofilm growth and within the matured biofilm community. Considering the prevalence of the highly conserved mat locus in E. coli genomes, we hypothesize that Mat fimbria-mediated biofilm formation is an ancestral characteristic of E. coli.

Bacterial Biofilms in Infective Endocarditis – A complex in vitro - Model to Investigate Emerging Technologies of Antimicrobial Cardiovascular Device Coatings

2020 ◽  
Author(s):  
Laura Kursawe ◽  
Alexander Lauten ◽  
Marc Martinović ◽  
Klaus Affeld ◽  
Ulrich Kertzscher ◽  
...  
Keyword(s):  
Infective Endocarditis ◽  
Heart Valves ◽  
In Vitro Model ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Aortic Valves ◽  
Biofilm Growth ◽  
Vitro Model ◽  
Biofilm Development

&lt;p&gt;&lt;strong&gt;Objective:&lt;/strong&gt; Most biofilm flow-chambers are designed for standardized homogeneous biofilms for research purposes. These do not mimic the complexity of prosthetic heart valves, which consist of both artificial and biological material.&lt;/p&gt; &lt;p&gt;Infective endocarditis (IE) is still associated with a high morbidity and mortality. IE is characterized by bacterial biofilms of the endocardium leading to destruction of the valve. Current research demonstrates that about one quarter of the patients with formal surgery indication cannot undergo surgery. This group of patients needs further options of therapy, but due to a lack of models for IE, prospects of research are low.&lt;/p&gt; &lt;p&gt;Therefore, the purpose of this project was to establish an in vitro - model of infective endocarditis to allow growth of bacterial biofilms on porcine aortic valves, serving as baseline for further research.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Methods and Results: &lt;/strong&gt;A pulsatile two-chamber circulation model was constructed that kept native porcine aortic valves under sterile, physiologic hemodynamic and temperature conditions. To exclude external contamination, sterility tests with sterile culture media were performed for 24h. During this time period, no growth of microorganisms was observed in the system and cultures after plating on standard media remained negative.&lt;/p&gt; &lt;p&gt;The system was inoculated with Staphylococcus epidermidis PIA 8400 to create biofilms on porcine aortic valves. Porcine aortic roots were incubated in this system for increasing periods of time and bacterial titration to evaluate bacterial growth and biofilm development on the valves. After incubation, specimens were embedded and tissue sections were analyzed by Fluorescence in situ hybridization (FISH) for direct visualization of the biofilms and bacterial activity.&lt;/p&gt; &lt;p&gt;Pilot tests for biofilm growth showed monospecies colonization consisting of cocci with time- and inocula-dependent increase. FISH visualized biofilms with ribosome-containing, and thus metabolic active cocci, tissue infiltration and similar colonization pattern as observed by FISH in human IE heart valves infected by S. epidermidis.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Conclusion:&lt;/strong&gt; These results demonstrate the establishment of a novel complex in vitro - model for bacterial biofilm growth on porcine aortic roots. The model will allow identifying predilection sites of heart valves for bacterial adhesion and biofilm growth and it may serve as baseline for further research on IE therapy and prevention, e.g. the development of antimicrobial transcatheter approaches to IE.&lt;/p&gt;

scholarly journals Hierarchical Rose Petal Surfaces Delay the Early-Stage Bacterial Biofilm Growth

Langmuir ◽  
2019 ◽  
Vol 35 (45) ◽  
pp. 14670-14680 ◽  
Author(s):  
Yunyi Cao ◽  
Saikat Jana ◽  
Leon Bowen ◽  
Xiaolong Tan ◽  
Hongzhong Liu ◽  
...  
Keyword(s):  
Early Stage ◽  
Bacterial Biofilm ◽  
Biofilm Growth ◽  
Rose Petal

scholarly journals Metabolic Remodeling during Biofilm Development ofBacillus subtilis

mBio ◽  
2019 ◽  
Vol 10 (3) ◽  
Author(s):  
Tippapha Pisithkul ◽  
Jeremy W. Schroeder ◽  
Edna A. Trujillo ◽  
Ponlkrit Yeesin ◽  
David M. Stevenson ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Regulatory Networks ◽  
Developmental Process ◽  
Central Carbon Metabolism ◽  
Bacterial Biofilm ◽  
Biofilm Growth ◽  
Time Resolved ◽  
Content Type ◽  
Metabolic Remodeling ◽  
Biofilm Development

ABSTRACTBiofilms are structured communities of tightly associated cells that constitute the predominant state of bacterial growth in natural and human-made environments. Although the core genetic circuitry that controls biofilm formation in model bacteria such asBacillus subtilishas been well characterized, little is known about the role that metabolism plays in this complex developmental process. Here, we performed a time-resolved analysis of the metabolic changes associated with pellicle biofilm formation and development inB. subtilisby combining metabolomic, transcriptomic, and proteomic analyses. We report surprisingly widespread and dynamic remodeling of metabolism affecting central carbon metabolism, primary biosynthetic pathways, fermentation pathways, and secondary metabolism. Most of these metabolic alterations were hitherto unrecognized as biofilm associated. For example, we observed increased activity of the tricarboxylic acid (TCA) cycle during early biofilm growth, a shift from fatty acid biosynthesis to fatty acid degradation, reorganization of iron metabolism and transport, and a switch from acetate to acetoin fermentation. Close agreement between metabolomic, transcriptomic, and proteomic measurements indicated that remodeling of metabolism during biofilm development was largely controlled at the transcriptional level. Our results also provide insights into the transcription factors and regulatory networks involved in this complex metabolic remodeling. Following upon these results, we demonstrated that acetoin production via acetolactate synthase is essential for robust biofilm growth and has the dual role of conserving redox balance and maintaining extracellular pH. This report represents a comprehensive systems-level investigation of the metabolic remodeling occurring duringB. subtilisbiofilm development that will serve as a useful road map for future studies on biofilm physiology.IMPORTANCEBacterial biofilms are ubiquitous in natural environments and play an important role in many clinical, industrial, and ecological settings. Although much is known about the transcriptional regulatory networks that control biofilm formation in model bacteria such asBacillus subtilis, very little is known about the role of metabolism in this complex developmental process. To address this important knowledge gap, we performed a time-resolved analysis of the metabolic changes associated with bacterial biofilm development inB. subtilisby combining metabolomic, transcriptomic, and proteomic analyses. Here, we report a widespread and dynamic remodeling of metabolism affecting central carbon metabolism, primary biosynthetic pathways, fermentation pathways, and secondary metabolism. This report serves as a unique hypothesis-generating resource for future studies on bacterial biofilm physiology. Outside the biofilm research area, this work should also prove relevant to any investigators interested in microbial physiology and metabolism.

scholarly journals Visible Light-Activated Carbon Dots for Inhibiting Biofilm Formation and Inactivating Biofilm-Associated Bacterial Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiuli Dong ◽  
Christopher M. Overton ◽  
Yongan Tang ◽  
Jasmine P. Darby ◽  
Ya-Ping Sun ◽  
...  
Keyword(s):  
Visible Light ◽  
Carbon Dots ◽  
Biofilm Formation ◽  
Chelating Agents ◽  
Early Stage ◽  
Inhibitory Effect ◽  
Bacterial Cells ◽  
Planktonic Cells ◽  
Biofilm Growth ◽  
Time Point

This study aimed to address the significant problems of bacterial biofilms found in medical fields and many industries. It explores the potential of classic photoactive carbon dots (CDots), with 2,2′-(ethylenedioxy)bis (ethylamine) (EDA) for dot surface functionalization (thus, EDA-CDots) for their inhibitory effect on B. subtilis biofilm formation and the inactivation of B. subtilis cells within established biofilm. The EDA-CDots were synthesized by chemical functionalization of selected small carbon nanoparticles with EDA molecules in amidation reactions. The inhibitory efficacy of CDots with visible light against biofilm formation was dependent significantly on the time point when CDots were added; the earlier the CDots were added, the better the inhibitory effect on the biofilm formation. The evaluation of antibacterial action of light-activated EDA-CDots against planktonic B. subtilis cells versus the cells in biofilm indicate that CDots are highly effective for inactivating planktonic cells but barely inactivate cells in established biofilms. However, when coupling with chelating agents (e.g., EDTA) to target the biofilm architecture by breaking or weakening the EPS protection, much enhanced photoinactivation of biofilm-associated cells by CDots was achieved. The study demonstrates the potential of CDots to prevent the initiation of biofilm formation and to inhibit biofilm growth at an early stage. Strategic combination treatment could enhance the effectiveness of photoinactivation by CDots to biofilm-associated cells.

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