scholarly journals Probiotics as Therapeutic Tools against Pathogenic Biofilms: Have We Found the Perfect Weapon?

2021 ◽  
Vol 12 (4) ◽  
pp. 916-937
Author(s):  
Gabriele Meroni ◽  
Simona Panelli ◽  
Gianvincenzo Zuccotti ◽  
Claudio Bandi ◽  
Lorenzo Drago ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Antimicrobial Agents ◽  
Current Knowledge ◽  
Effective Means ◽  
Bacterial Populations ◽  
Implanted Medical Devices ◽  
Therapeutic Tools ◽  
Pathogenic Biofilms

Bacterial populations inhabiting a variety of natural and human-associated niches have the ability to grow in the form of biofilms. A large part of pathological chronic conditions, and essentially all the bacterial infections associated with implanted medical devices or prosthetics, are caused by microorganisms embedded in a matrix made of polysaccharides, proteins, and nucleic acids. Biofilm infections are generally characterized by a slow onset, mild symptoms, tendency to chronicity, and refractory response to antibiotic therapy. Even though the molecular mechanisms responsible for resistance to antimicrobial agents and host defenses have been deeply clarified, effective means to fight biofilms are still required. Lactic acid bacteria (LAB), used as probiotics, are emerging as powerful weapons to prevent adhesion, biofilm formation, and control overgrowth of pathogens. Hence, using probiotics or their metabolites to quench and interrupt bacterial communication and aggregation, and to interfere with biofilm formation and stability, might represent a new frontier in clinical microbiology and a valid alternative to antibiotic therapies. This review summarizes the current knowledge on the experimental and therapeutic applications of LAB to interfere with biofilm formation or disrupt the stability of pathogenic biofilms.

scholarly journals Recent Advances in Surface Nanoengineering for Biofilm Prevention and Control. Part I: Molecular Basis of Biofilm Recalcitrance. Passive Anti-Biofouling Nanocoatings

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1230 ◽  
Author(s):  
Paul Cătălin Balaure ◽  
Alexandru Mihai Grumezescu
Keyword(s):  
Life Cycle ◽  
Molecular Mechanisms ◽  
Antimicrobial Agents ◽  
Current Knowledge ◽  
Emergent Properties ◽  
Bacterial Cells ◽  
Life Cycle Stages ◽  
Fouling Release ◽  
Biofilm Development ◽  
And Control

Medical device-associated infections are becoming a leading cause of morbidity and mortality worldwide, prompting researchers to find new, more effective ways to control the bacterial colonisation of surfaces and biofilm development. Bacteria in biofilms exhibit a set of “emergent properties”, meaning those properties that are not predictable from the study of free-living bacterial cells. The social coordinated behaviour in the biofilm lifestyle involves intricate signaling pathways and molecular mechanisms underlying the gain in resistance and tolerance (recalcitrance) towards antimicrobial agents as compared to free-floating bacteria. Nanotechnology provides powerful tools to disrupt the processes responsible for recalcitrance development in all stages of the biofilm life cycle. The present paper is a state-of-the-art review of the surface nanoengineering strategies currently used to design antibiofilm coatings. The review is structurally organised in two parts according to the targeted biofilm life cycle stages and molecular mechanisms intervening in recalcitrance development. Therefore, in the present first part, we begin with a presentation of the current knowledge of the molecular mechanisms responsible for increased recalcitrance that have to be disrupted. Further, we deal with passive surface nanoengineering strategies that aim to prevent bacterial cells from settling onto a biotic or abiotic surface. Both “fouling-resistant” and “fouling release” strategies are addressed as well as their synergic combination in a single unique nanoplatform.

scholarly journals Bacterial Quorum Sensing and Microbial Community Interactions

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Rhea G. Abisado ◽  
Saida Benomar ◽  
Jennifer R. Klaus ◽  
Ajai A. Dandekar ◽  
Josephine R. Chandler
Keyword(s):  
Quorum Sensing ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Cell Communication ◽  
Microbial Interactions ◽  
Community Interactions ◽  
Bacterial Populations ◽  
Bacterial Quorum Sensing ◽  
A Cell ◽  
Bacterial Quorum

ABSTRACTMany bacteria use a cell-cell communication system called quorum sensing to coordinate population density-dependent changes in behavior. Quorum sensing involves production of and response to diffusible or secreted signals, which can vary substantially across different types of bacteria. In many species, quorum sensing modulates virulence functions and is important for pathogenesis. Over the past half-century, there has been a significant accumulation of knowledge of the molecular mechanisms, signal structures, gene regulons, and behavioral responses associated with quorum-sensing systems in diverse bacteria. More recent studies have focused on understanding quorum sensing in the context of bacterial sociality. Studies of the role of quorum sensing in cooperative and competitive microbial interactions have revealed how quorum sensing coordinates interactions both within a species and between species. Such studies of quorum sensing as a social behavior have relied on the development of “synthetic ecological” models that use nonclonal bacterial populations. In this review, we discuss some of these models and recent advances in understanding how microbes might interact with one another using quorum sensing. The knowledge gained from these lines of investigation has the potential to guide studies of microbial sociality in natural settings and the design of new medicines and therapies to treat bacterial infections.

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.

Spectrum and Antibiotic Resistance Pattern of Bacteria Causing Urinary Tract Infections (UTI) in a Tertiary Care Hospital

2020 ◽  
Vol 23 (1) ◽  
pp. 13-18
Author(s):  
Sadia Afroz ◽  
Zakir Hossain Habib ◽  
Syed Muhammad Baqui Billah ◽  
Hasina Akhter ◽  
Hosne Jahan ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Current Knowledge ◽  
Clinical Sample ◽  
Evaluation Studies ◽  
Tertiary Care ◽  
Resistance Pattern ◽  
Care Hospital ◽  
Tract Infections

Background: Urinary tract infection (UTI) is one of the most common bacterial infections encountered by clinicians particularly in developing countries. Current knowledge on antimicrobial resistance pattern is essential for appropriate therapy. The aim of the present study was to identify the causative organisms for UTI and to determine the antibiotic susceptibility pattern of organisms causing UTI. Method: This cross sectional study was carried out in the department of Microbiology, Sir Salimullah Medical College, Dhaka, from a period of January 2014 to December 2014. Results: Out of 2136 clinical sample of urine, 430 (20.1%) showed significant bacterial growth. Escherichia coli was the commonest urinary pathogen (76.3%), followed by Pseudomonas spp. (7.9%), Proteus spp. (7.2%), Klebsiella spp., Citrobacter spp. (1.9% each) and Staphylococcus aureus (1.6%). Isolated uropathogens showed highest resistance for Amoxycillin (86%-97%) and Cefradin (71%-100%), resistance rate for other commonly used antimicrobial agents was high; Cefixime (52%-85%), Ceftriaxone (50%-71%), Ciprofloxacin (50%-88%), Cotrimoxazole (50%-75%), Gentamicin (57%-75%) and Nitrofurantoin (43%-100%), while uropathogens were least resistant to Imipenem (0%-15%) and Amikacin (0%-29%). Conclusion: Due to high degree of resistance to commonly used antimicrobials to treat UTI, routine monitoring and evaluation studies should be conducted to update physicians’ knowledge about most effective antibiotics for treatment of UTI. Journal of Surgical Sciences (2019) Vol. 23 (1) : 13-18

scholarly journals Effect of Farnesol on Staphylococcus aureus Biofilm Formation and Antimicrobial Susceptibility

2006 ◽  
Vol 50 (4) ◽  
pp. 1463-1469 ◽  
Author(s):  
M. A. Jabra-Rizk ◽  
T. F. Meiller ◽  
C. E. James ◽  
M. E. Shirtliff
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Membrane Integrity ◽  
Antimicrobial Properties ◽  
Bloodstream Infections ◽  
High Concentration ◽  
Bacterial Populations ◽  
Cell Membrane Integrity ◽  
Plate Counts

ABSTRACT Staphylococcus aureus is among the leading pathogens causing bloodstream infections able to form biofilms on host tissue and indwelling medical devices and to persist and cause disease. Infections caused by S. aureus are becoming more difficult to treat because of increasing resistance to antibiotics. In a biofilm environment particularly, microbes exhibit enhanced resistance to antimicrobial agents. Recently, farnesol was described as a quorum-sensing molecule with possible antimicrobial properties. In this study, the effect of farnesol on methicillin-resistant and -susceptible strains of S. aureus was investigated. With viability assays, biofilm formation assessment, and ethidium bromide uptake testing, farnesol was shown to inhibit biofilm formation and compromise cell membrane integrity. The ability of farnesol to sensitize S. aureus to antimicrobials was assessed by agar disk diffusion and broth microdilution methods. For both strains of staphylococci, farnesol was only able to reverse resistance at a high concentration (150 μM). However, it was very successful at enhancing the antimicrobial efficacy of all of the antibiotics to which the strains were somewhat susceptible. Therefore, synergy testing of farnesol and gentamicin was performed with static biofilms exposed to various concentrations of both agents. Plate counts of harvested biofilm cells at 0, 4, and 24 h posttreatment indicated that the combined effect of gentamicin at 2.5 times the MIC and farnesol at 100 μM (22 μg/ml) was able to reduce bacterial populations by more than 2 log units, demonstrating synergy between the two antimicrobial agents. This observed sensitization of resistant strains to antimicrobials and the observed synergistic effect with gentamicin indicate a potential application for farnesol as an adjuvant therapeutic agent for the prevention of biofilm-related infections and promotion of drug resistance reversal.

scholarly journals Crosstalk Between Staphylococcus aureus and Innate Immunity: Focus on Immunometabolism

2021 ◽  
Vol 11 ◽  
Author(s):  
Christopher M. Horn ◽  
Tammy Kielian
Keyword(s):  
Staphylococcus Aureus ◽  
Metabolic Pathways ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Current Knowledge ◽  
Innate Immune ◽  
Community Settings ◽  
Leukocyte Activation ◽  
Inflammatory Status ◽  
Novel Therapeutic Strategies

Staphylococcus aureus is a leading cause of bacterial infections globally in both healthcare and community settings. The success of this bacterium is the product of an expansive repertoire of virulence factors in combination with acquired antibiotic resistance and propensity for biofilm formation. S. aureus leverages these factors to adapt to and subvert the host immune response. With the burgeoning field of immunometabolism, it has become clear that the metabolic program of leukocytes dictates their inflammatory status and overall effectiveness in clearing an infection. The metabolic flexibility of S. aureus offers an inherent means by which the pathogen could manipulate the infection milieu to promote its survival. The exact metabolic pathways that S. aureus influences in leukocytes are not entirely understood, and more work is needed to understand how S. aureus co-opts leukocyte metabolism to gain an advantage. In this review, we discuss the current knowledge concerning how metabolic biases dictate the pro- vs. anti-inflammatory attributes of various innate immune populations, how S. aureus metabolism influences leukocyte activation, and compare this with other bacterial pathogens. A better understanding of the metabolic crosstalk between S. aureus and leukocytes may unveil novel therapeutic strategies to combat these devastating infections.

scholarly journals Differential expression of DLG1 as a common trait in different human diseases: an encouraging issue in molecular pathology

2019 ◽  
Vol 400 (6) ◽  
pp. 699-710 ◽  
Author(s):  
Federico Marziali ◽  
María Paula Dizanzo ◽  
Ana Laura Cavatorta ◽  
Daniela Gardiol
Keyword(s):  
Posttranslational Modifications ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Gene Mutations ◽  
Scaffolding Protein ◽  
Cellular Processes ◽  
Cell Localization ◽  
Open Questions ◽  
Therapeutic Tools ◽  
And Migration

AbstractHuman disc large (DLG1) is a scaffolding protein that through the interaction with diverse cell partners participates in the control of key cellular processes such as polarity, proliferation and migration. Experimental data have mainly identified DLG1 as a tumor suppressor. An outstanding point for DLG1 protein is that altered DLG1 expression andDLG1gene mutations were observed in different pathologies, including cancer and neurological and immunological disorders. Evident changes in DLG1 abundance and/or cell localization were identified in a number of studies suggesting its participation in molecular mechanisms responsible for the development of such illnesses. In this review, we focus on some of the latest findings regarding DLG1 alterations in different diseases as well as its potential use as a biomarker for pathological progression. We further address the current knowledge on the molecular mechanisms regulating DLG1 expression and the posttranslational modifications that may affect DLG1 cell localization and functions. Despite the advances in this field, there are still open questions about the precise molecular link between alterations in DLG1 expression and the development of each specific pathology. The complete understanding of this concern will give us new scenarios for the design of promising diagnosis and therapeutic tools.

Molecular mechanisms regulating the catabolic and electrochemical activities of Shewanella oneidensis MR-1

2021 ◽  
Author(s):  
Atsushi Kouzuma
Keyword(s):  
Microbial Fuel Cells ◽  
Biofilm Formation ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Shewanella Oneidensis ◽  
Extracellular Electron Transfer ◽  
Cellular Functions ◽  
Regulatory Systems ◽  
Electrochemically Active ◽  
Recent Developments

Abstract Electrochemically active bacteria (EAB) interact electrochemically with electrodes via extracellular electron transfer (EET) pathways. These bacteria have attracted significant attention due to their utility in environment-friendly bioelectrochemical systems (BESs), e.g. microbial fuel cells and electrofermentation systems. The electrochemical activity of EAB is dependent on their carbon catabolism and respiration; thus, understanding how these processes are regulated will provide insights into the development of a more efficient BES. The process of biofilm formation by EAB on BES electrodes is also important for electric current generation, because it facilitates physical and electrochemical interactions between EAB cells and electrodes. This article summarizes the current knowledge on EET-related metabolic and cellular functions of a model EAB, Shewanella oneidensis MR-1, focusing specifically on regulatory systems for carbon catabolism, EET pathways, and biofilm formation. Based on recent developments, the author also discusses potential uses of engineered S. oneidensis strains for various biotechnological applications.

scholarly journals GoniothalamusSpecies: A Source of Drugs for the Treatment of Cancers and Bacterial Infections?

2007 ◽  
Vol 4 (3) ◽  
pp. 299-311 ◽  
Author(s):  
Christophe Wiart
Keyword(s):  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Cytotoxic Effects ◽  
Medicinal Uses ◽  
Gram Positive Bacteria ◽  
Trail Receptors ◽  
Pharmacological Studies ◽  
Botanical Description ◽  
Styryl Lactones

Irrespective of the presence of cytotoxic acetogenins and styryl-lactones in the genusGoniothalamus, only 22 species in the genusGoniothalamus, out of 160 species (13.7%) have so far been investigated. In an effort to promote further research on the genusGoniothalamuswhich could represent a source of drugs for the treatment of cancers and bacterial infections, this work offers a broad analysis of current knowledge onGoniothalamusspecies. Therefore, it includes (i) taxonomy (ii) botanical description (iii) traditional medicinal uses and (iv) phytochemical and pharmacological studies. We discuss the molecular mechanisms of actions of acetogenins and styryl-lactones, with some emphasis on the possible involvement of protein kinase, Bax and TRAIL receptors in the cytotoxic effects of styryl-lactones. We also report (v) the growth inhibition of several nosocomial bacteria byGoniothalamus. scortechinii. The crude methanol extract ofG. scortechiniishowed a good and broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria.

scholarly journals Inhibition of Pseudomonas aeruginosa Biofilm Formation by Traditional Chinese Medicinal Herb Herba patriniae

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Bo Fu ◽  
Qiaolian Wu ◽  
Minyan Dang ◽  
Dangdang Bai ◽  
Qiao Guo ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Inhibitory Effect ◽  
New Drugs ◽  
Chinese Herbs ◽  
Reporter System ◽  
Chinese Medicinal Herb ◽  
Almost All

New antimicrobial agents are urgently needed to treat infections caused by drug-resistant pathogens and by pathogens capable of persisting in biofilms. The aim of this study was to identify traditional Chinese herbs that could inhibit biofilm formation of Pseudomonas aeruginosa, an important human pathogen that causes serious and difficult-to-treat infections in humans. A luxCDABE-based reporter system was constructed to monitor the expression of six key biofilm-associated genes in P. aeruginosa. The reporters were used to screen a library of 36 herb extracts for inhibitory properties against these genes. The results obtained indicated that the extract of Herba patriniae displayed significant inhibitory effect on almost all of these biofilm-associated genes. Quantitative analysis showed that H. patriniae extract was able to significantly reduce the biofilm formation and dramatically altered the structure of the mature biofilms of P. aeruginosa. Further studies showed H. patriniae extract decreased exopolysaccharide production by P. aeruginosa and promoted its swarming motility, two features disparately associated with biofilm formation. These results provided a potential mechanism for the use of H. patriniae to treat bacterial infections by traditional Chinese medicines and revealed a promising candidate for exploration of new drugs against P. aeruginosa biofilm-associated infections.

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