scholarly journals Multi-targeted Antisense Oligonucleotide Delivery by a Framework Nucleic Acid for Inhibiting Biofilm Formation and Virulence

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuxin Zhang ◽  
Xueping Xie ◽  
Wenjuan Ma ◽  
Yuxi Zhan ◽  
Chenchen Mao ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Antisense Oligonucleotide ◽  
Biofilm Formation ◽  
Extracellular Polysaccharides ◽  
Nucleic Acid Delivery ◽  
Bacterial Cells ◽  
Chronic Infections ◽  
Tetrahedral Configuration ◽  
Biofilm Thickness ◽  
Targeted Inhibition

AbstractBiofilm formation is responsible for numerous chronic infections and represents a serious health challenge. Bacteria and the extracellular polysaccharides (EPS) cause biofilms to become adherent, toxic, resistant to antibiotics, and ultimately difficult to remove. Inhibition of EPS synthesis can prevent the formation of bacterial biofilms, reduce their robustness, and promote removal. Here, we have developed a framework nucleic acid delivery system with a tetrahedral configuration. It can easily access bacterial cells and functions by delivering antisense oligonucleotides that target specific genes. We designed antisense oligonucleotide sequences with multiple targets based on conserved regions of the VicK protein-binding site. Once delivered to bacterial cells, they significantly decreased EPS synthesis and biofilm thickness. Compared to existing approaches, this system is highly efficacious because it simultaneously reduces the expression of all targeted genes (gtfBCD, gbpB, ftf). We demonstrate a novel nucleic acid-based nanomaterial with multi-targeted inhibition that has great potential for the treatment of chronic infections caused by biofilms.

scholarly journals A Sustained-Release Membrane of Thiazolidinedione-8: Effect on Formation of a Candida/Bacteria Mixed Biofilm on Hydroxyapatite in a Continuous Flow Model

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Mark Feldman ◽  
Julia Shenderovich ◽  
Eran Lavy ◽  
Michael Friedman ◽  
Doron Steinberg
Keyword(s):  
Sustained Release ◽  
Biofilm Formation ◽  
Active Agent ◽  
Extracellular Polysaccharides ◽  
Flow Conditions ◽  
Biofilm Thickness ◽  
Release Drug ◽  
Flow Through ◽  
Biofilm Development ◽  
The Impact

Thiazolidinediones (TZDs) have been found to act as effective quorum sensing quenchers, capable of preventing biofilm formation. Our previous studies demonstrated a profound antibiofilm effect of the TZD derivative thiazolidinedione-8 (S-8), either in solution or incorporated into a sustained-release membrane (SRM-S-8) under batch conditions. In the present study, we used a constant depth film fermenter model in order to investigate the impact of SRM-S-8 on mixedC. albicans-S. mutansbiofilm development, under flow conditions. We found that essential parameters of cospecies biofilm maintenance and maturation, such as metabolic activity, biofilm thickness, roughness, extracellular polysaccharides production, and morphology of both pathogens, were altered by SRM-S-8 in the flow system. We propose that prolonged and sustained release of S-8 in a flow-through system allows better penetration of the active agent to deeper layers of the mixed biofilm, thereby increasing its activity against both pathogens. In conclusion, the use of a locally applied sustained-release drug delivery system of S-8 can affect the dental polymicrobial biofilm, resulting in clinical improvements and a better patient compliance.

scholarly journals Differences among clinical isolates of Pseudomonas aeruginosa in their capability of forming biofilms and their susceptibility to antibiotics

2019 ◽  
Vol 20 (5) ◽  
Author(s):  
DIDIK WAHYUDI ◽  
ABU THOLIB AMAN ◽  
NIKEN SATUTI NUR HANDAYANI ◽  
ENDANG SUTARININGSIH SOETARTO
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Test Method ◽  
Clinical Isolates ◽  
Gene Identification ◽  
Bacterial Cells ◽  
Bacterial Identification ◽  
Chronic Infections ◽  
Automatic Equipment ◽  
Polymerase Chain

Abstract. Wahyudi D, Aman AT, Handayani NSN, Soetarto ES. 2019. Differences among clinical isolates of Pseudomonas aeruginosa in their capability of forming biofilms and their susceptibility to antibiotics. Biodiversitas 20: 1450-1456. Pseudomonas aeruginosa is an important nosocomial pathogen capable of causing both acute and chronic infections. The individuals of this bacterium have differences in their capability of forming biofilms.  Biofilm is a collection of bacterial cells attached to the tissue, coated by polysaccharides and extracellular matrix, enabling bacteria to become resistant to antibiotics, so infection is difficult to treat.  The aim of this study was to know the differences among clinical isolates of Pseudomonas aeruginosa in their capability of forming biofilms, and their susceptibility to some antibiotics. The bacteria were isolated from various patient samples at Dr. Moewardi Hospital Surakarta, Indonesia, from August to December 2017. The isolates were purified using single cell colony technique.  The bacterial identification and tests of susceptibility to many antibiotic were conducted using automatic equipment (vitex® 2). Test method of biofilm formation was done using the Tissue Culture Plate. The readings of results were monitored spectrophotometrically at a wavelength of 570 nm and repeated 8 times. DNA isolation was done using Qiagen DNeasy Blood and Tissue Kit, and gene identification (pelD and pslA) was done using PCR (Polymerase Chain Reaction) and visualization through electrophoresis.  The results showed that of the 64 isolates of P. aeruginosa from blood, sputum, urine, ear middle, urine catheter, pleural fluid, pus, stool, aspirate, and cerebrospinal, 22% were low in forming biofilm, 50% moderate, and 28% high. Isolates of P. aeruginosa were resistant to ampicillin, cefazolin, tigecycline, nirofurantoin, and cotrimoxazole, but sensitive to piperacillin, ceftazidime, cefepime, aztreonam, meropenem, amikacin, gentamicin, and ciprofloxacin. The genes of pelD and pslA were present in all P. aeruginosa isolates (low, moderate, dan high).   In conclusion, P. aeruginosa clinical isolates had different capability of forming biofilms and susceptibility to antibiotics. Isolates having high ability to form biofilm were relatively more resistant to many antibiotics. They were most sensitive to amikacin and resistant to ampicillin.  There was no difference in the presence of mop pelD and pslA among all isolates.

scholarly journals Signal Sensing and Transduction Are Conserved between the Periplasmic Sensory Domains of BifA and SagS

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Jozef Dingemans ◽  
Rebecca E. Al-Feghali ◽  
Holger Sondermann ◽  
Karin Sauer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Structural Similarity ◽  
Opportunistic Pathogen ◽  
Sequence Conservation ◽  
Sensor Kinase ◽  
Antibiotic Tolerance ◽  
Bacterial Cells ◽  
Chronic Infections ◽  
Content Type

ABSTRACT The hybrid sensor kinase SagS of Pseudomonas aeruginosa plays a key role in the transition from the planktonic to the biofilm mode of growth. Recently, we have shown that distinct sets of residues in its periplasmic HmsP sensory domain are involved in the regulation of biofilm formation or antibiotic tolerance. Interestingly, the HmsP domain of the phosphodiesterase BifA shows great predicted structural similarity to that of SagS, despite moderate sequence conservation and only a number of residues involved in SagS signaling being conserved between both proteins. Based on this observation, we hypothesized that BifA and SagS may use similar mechanisms to sense and transduce signals perceived at their periplasmic HmsP domains and, therefore, may be interchangeable. To test this hypothesis, we constructed SagS hybrids in which the HmsP domain of SagS was replaced by that of BifA (and vice versa) or by the DISMED2 sensory domain of NicD. The SagS-BifA hybrid restored attachment and biofilm formation by the ΔbifA mutant. Likewise, while the NicD-SagS hybrid was nonfunctional, the BifA-SagS hybrid partially restored pathways leading to biofilm formation and antibiotic tolerance in a ΔsagS mutant background. Furthermore, alanine substitution of key residues previously associated with the biofilm formation and antibiotic tolerance pathways of SagS impaired signal transduction by the BifA-SagS hybrid in a similar way to SagS. In conclusion, our data indicate that the nature of the sensory domain is important for proper functionality of the cytoplasmic effector domains and that signal sensing and transduction are likely conserved in SagS and BifA. IMPORTANCE Biofilms have been associated with more than 60% of all recalcitrant and chronic infections and can render bacterial cells up to a thousand times more resistant to antibiotics than planktonic cells. Although it is known that the transition from the planktonic to the biofilm mode of growth involves two-component regulatory systems, increased c-di-GMP levels, and quorum sensing systems among others, the exact signaling events that lead to biofilm formation remain unknown. In the opportunistic pathogen Pseudomonas aeruginosa, the hybrid sensor kinase SagS regulates biofilm formation and antibiotic tolerance through two independent pathways via distinct residues in its periplasmic sensory domain. Interestingly, the sensory domains of SagS and BifA show great predicted structural similarity despite moderate sequence conservation. Here we show that the sensory domains of BifA and SagS are functionally interchangeable and that they use a similar mechanism of signal sensing and transduction, which broadens our understanding of how bacteria perceive and transduce signals when transitioning to the biofilm mode of growth.

scholarly journals BolA Is a Transcriptional Switch That Turns Off Motility and Turns On Biofilm Development

mBio ◽  
2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Clémentine Dressaire ◽  
Ricardo Neves Moreira ◽  
Susana Barahona ◽  
António Pedro Alves de Matos ◽  
Cecília Maria Arraiano
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Extracellular Polysaccharides ◽  
Bacterial Cells ◽  
Content Type ◽  
Bacterial Transcription ◽  
A Genome ◽  
Exact Function ◽  
Transcriptional Switch ◽  
Biofilm Development

ABSTRACTBacteria are extremely versatile organisms that rapidly adapt to changing environments. When bacterial cells switch from planktonic growth to biofilm, flagellum formation is turned off and the production of fimbriae and extracellular polysaccharides is switched on. BolA is present in most Gram-negative bacteria, and homologues can be found from proteobacteria to eukaryotes. Here, we show that BolA is a new bacterial transcription factor that modulates the switch from a planktonic to a sessile lifestyle. It negatively modulates flagellar biosynthesis and swimming capacity inEscherichia coli. Furthermore, BolA overexpression favors biofilm formation, involving the production of fimbria-like adhesins and curli. Our results also demonstrate that BolA is a protein with high affinity to DNA and is able to regulate many genes on a genome-wide scale. Moreover, we show that the most significant targets of this protein involve a complex network of genes encoding proteins related to biofilm development. Herein, we propose that BolA is a motile/adhesive transcriptional switch, specifically involved in the transition between the planktonic and the attachment stage of biofilm formation.IMPORTANCEEscherichia colicells possess several mechanisms to cope with stresses. BolA has been described as a protein important for survival in late stages of bacterial growth and under harsh environmental conditions. BolA-like proteins are widely conserved from prokaryotes to eukaryotes. Although their exact function is not fully established at the molecular level, they seem to be involved in cell proliferation or cell cycle regulation. Here, we unraveled the role of BolA in biofilm development and bacterial motility. Our work suggests that BolA actively contributes to the decision of bacteria to arrest flagellar production and initiate the attachment to form structured communities, such as biofilms. The molecular studies of different lifestyles coupled with the comprehension of the BolA functions may be an important step for future perspectives, with health care and biotechnology applications.

scholarly journals Capsular Polysaccharide Interferes with Biofilm Formation byPasteurella multocidaSerogroup A

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Briana Petruzzi ◽  
Robert E. Briggs ◽  
W. Edward Swords ◽  
Cristina De Castro ◽  
Antonio Molinaro ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Pasteurella Multocida ◽  
Capsular Polysaccharide ◽  
Glycogen Synthesis ◽  
Matrix Material ◽  
Carrier State ◽  
Gas Chromatography Mass Spectrometry ◽  
Atrophic Rhinitis ◽  
Bacterial Cells ◽  
Chronic Infections

ABSTRACTPasteurella multocidais an important multihost animal and zoonotic pathogen that is capable of causing respiratory and multisystemic diseases, bacteremia, and bite wound infections. The glycosaminoglycan capsule ofP. multocidais an essential virulence factor that protects the bacterium from host defenses. However, chronic infections (such as swine atrophic rhinitis and the carrier state in birds and other animals) may be associated with biofilm formation, which has not been characterized inP. multocida. Biofilm formation by clinical isolates was inversely related to capsule production and was confirmed with capsule-deficient mutants of highly encapsulated strains. Capsule-deficient mutants formed biofilms with a larger biomass that was thicker and smoother than the biofilm of encapsulated strains. Passage of a highly encapsulated, poor-biofilm-forming strain under conditions that favored biofilm formation resulted in the production of less capsular polysaccharide and a more robust biofilm, as did addition of hyaluronidase to the growth medium of all of the strains tested. The matrix material of the biofilm was composed predominately of a glycogen exopolysaccharide (EPS), as determined by gas chromatography-mass spectrometry, nuclear magnetic resonance, and enzymatic digestion. However, a putative glycogen synthesis locus was not differentially regulated when the bacteria were grown as a biofilm or planktonically, as determined by quantitative reverse transcriptase PCR. Therefore, the negatively charged capsule may interfere with biofilm formation by blocking adherence to a surface or by preventing the EPS matrix from encasing large numbers of bacterial cells. This is the first detailed description of biofilm formation and a glycogen EPS byP. multocida.IMPORTANCEPasteurella multocidais an important pathogen responsible for severe infections in food animals, domestic and wild birds, pet animals, and humans.P. multocidawas first isolated by Louis Pasteur in 1880 and has been studied for over 130 years. However, aspects of its lifecycle have remained unknown. Although formation of a biofilm byP. multocidahas been proposed, this report is the first to characterize biofilm formation byP. multocida. Of particular interest is that the biofilm matrix material contained a newly reported amylose-like glycogen as the exopolysaccharide component and that production of capsular polysaccharide (CPS) was inversely related to biofilm formation. However, even highly mucoid, poor-biofilm-forming strains could form abundant biofilms by loss of CPS or followingin vitropassage under biofilm growth conditions. Therefore, the carrier state or subclinical chronic infections withP. multocidamay result from CPS downregulation with concomitant enhanced biofilm formation.

scholarly journals Human Host Defense Peptide LL-37 Prevents Bacterial Biofilm Formation

2008 ◽  
Vol 76 (9) ◽  
pp. 4176-4182 ◽  
Author(s):  
Joerg Overhage ◽  
Andrea Campisano ◽  
Manjeet Bains ◽  
Ellen C. W. Torfs ◽  
Bernd H. A. Rehm ◽  
...  
Keyword(s):  
Host Defense ◽  
Biofilm Formation ◽  
Model Organism ◽  
Critical Factor ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
Chronic Infections ◽  
Host Defense Peptide ◽  
Biofilm Development

ABSTRACT The ability to form biofilms is a critical factor in chronic infections by Pseudomonas aeruginosa and has made this bacterium a model organism with respect to biofilm formation. This study describes a new, previously unrecognized role for the human cationic host defense peptide LL-37. In addition to its key role in modulating the innate immune response and weak antimicrobial activity, LL-37 potently inhibited the formation of bacterial biofilms in vitro. This occurred at the very low and physiologically meaningful concentration of 0.5 μg/ml, far below that required to kill or inhibit growth (MIC = 64 μg/ml). LL-37 also affected existing, pregrown P. aeruginosa biofilms. Similar results were obtained using the bovine neutrophil peptide indolicidin, but no inhibitory effect on biofilm formation was detected using subinhibitory concentrations of the mouse peptide CRAMP, which shares 67% identity with LL-37, polymyxin B, or the bovine bactenecin homolog Bac2A. Using microarrays and follow-up studies, we were able to demonstrate that LL-37 affected biofilm formation by decreasing the attachment of bacterial cells, stimulating twitching motility, and influencing two major quorum sensing systems (Las and Rhl), leading to the downregulation of genes essential for biofilm development.

Process Description of an Unconventional Biofilm Formation by Bacterial Cells Autoagglutinating Through Sticky, Long, and Peritrichate Nanofibers

2019 ◽  
Author(s):  
Yoshihide Furuichi ◽  
Shogo Yoshimoto ◽  
Tomohiro Inaba ◽  
Nobuhiko Nomura ◽  
Katsutoshi Hori
Keyword(s):  
Formation Process ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Waste Treatment ◽  
Large Cell ◽  
Dlvo Theory ◽  
Bacterial Cells ◽  
Chemical Production ◽  
Discontinuous Surface ◽  
Cell Cell

<p></p><p>Biofilms are used in environmental biotechnologies including waste treatment and environmentally friendly chemical production. Understanding the mechanisms of biofilm formation is essential to control microbial behavior and improve environmental biotechnologies. <i>Acinetobacter </i>sp. Tol 5 autoagglutinate through the interaction of the long, peritrichate nanofiber protein AtaA, a trimeric autotransporter adhesin. Using AtaA, without cell growth or the production of extracellular polymeric substances, Tol 5 cells quickly form an unconventional biofilm. In this study, we investigated the formation process of this unconventional biofilm, which started with cell–cell interactions, proceeded to cell clumping, and led to the formation of large cell aggregates. The cell–cell interaction was described by DLVO theory based on a new concept, which considers two independent interactions between two cell bodies and between two AtaA fiber tips forming a virtual discontinuous surface. If cell bodies cannot collide owing to an energy barrier at low ionic strengths but approach within the interactive distance of AtaA fibers, cells can agglutinate through their contact. Cell clumping proceeds following the cluster–cluster aggregation model, and an unconventional biofilm containing void spaces and a fractal nature develops. Understanding its formation process would extend the utilization of various types of biofilms, enhancing environmental biotechnologies.</p><p></p>

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

Non-Viral Nucleic Acid Delivery: Key Challenges and Future Directions

2011 ◽  
Vol 8 (3) ◽  
pp. 235-244 ◽  
Author(s):  
Mahmoud Elsabahy ◽  
Adil Nazarali ◽  
Marianna Foldvari
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acid Delivery ◽  
Viral Nucleic Acid ◽  
Future Directions

Modulation of Gut Microbiota through Dietary Phytochemicals as a Novel Anti-infective Strategy

2020 ◽  
Vol 17 (4) ◽  
pp. 498-506 ◽  
Author(s):  
Pavan K. Mujawdiya ◽  
Suman Kapur
Keyword(s):  
Microbial Community ◽  
Quorum Sensing ◽  
Population Density ◽  
Gut Microbiota ◽  
Biofilm Formation ◽  
Chemical Interaction ◽  
Bacterial Species ◽  
Critical Role ◽  
Bacterial Cells ◽  
Gut Microbes

: Quorum Sensing (QS) is a phenomenon in which bacterial cells communicate with each other with the help of several low molecular weight compounds. QS is largely dependent on population density, and it triggers when the concentration of quorum sensing molecules accumulate in the environment and crosses a particular threshold. Once a certain population density is achieved and the concentration of molecules crosses a threshold, the bacterial cells show a collective behavior in response to various chemical stimuli referred to as “auto-inducers”. The QS signaling is crucial for several phenotypic characteristics responsible for bacterial survival such as motility, virulence, and biofilm formation. Biofilm formation is also responsible for making bacterial cells resistant to antibiotics. : The human gut is home to trillions of bacterial cells collectively called “gut microbiota” or “gut microbes”. Gut microbes are a consortium of more than 15,000 bacterial species and play a very crucial role in several body functions such as metabolism, development and maturation of the immune system, and the synthesis of several essential vitamins. Due to its critical role in shaping human survival and its modulating impact on body metabolisms, the gut microbial community has been referred to as “the forgotten organ” by O`Hara et al. (2006) [1]. Several studies have demonstrated that chemical interaction between the members of bacterial cells in the gut is responsible for shaping the overall microbial community. : Recent advances in phytochemical research have generated a lot of interest in finding new, effective, and safer alternatives to modern chemical-based medicines. In the context of antimicrobial research various plant extracts have been identified with Quorum Sensing Inhibitory (QSI) activities among bacterial cells. This review focuses on the mechanism of quorum sensing and quorum sensing inhibitors isolated from natural sources.

Sign in / Sign up

Export Citation Format

Share Document