scholarly journals Antimicrobial Resistance in Oral biofilm: Challenges and Alternatives

2021 ◽  
Vol 12 (1) ◽  
pp. 349-356
Author(s):  
Satish Kumar Sharma ◽  
Shmmon Ahmad
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Target Cells ◽  
Bacterial Cells ◽  
Antimicrobial Drugs ◽  
Oral Infections

Bacterial biofilm has been a major contributor to severe bacterial infections in humans. Oral infections have also been associated with biofilm-forming microbes. Several antimicrobial strategies have been developed to combat bacterial biofilms. However, the complexity of the oral cavity has made it difficult to use common drug treatments. Most effective ways to control normal bacterial infections are rendered ineffective for bacterial biofilms. Due to limited drug concentration availability, drug neutralization or altered phenotype of bacterial cells, different drug have been ineffective to identify the target cells. This leads to the development of the multifaceted phenomenon of antimicrobial resistance (AMR). Biofilm research done so far has been focused on using antimicrobial drugs to target molecular mechanisms of cells. The severity and resistance mechanisms of extracellular matrix (ECM) have been underestimated. The present study describes different antimicrobial strategies with respect to their applications in dental or oral infections. A prospective strategy has been proposed targeting ECM which is expected to provide an insight on biofilm obstinacy and antimicrobial resistance.

scholarly journals Liposomes as Antibiotic Delivery Systems: A Promising Nanotechnological Strategy against Antimicrobial Resistance

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2047
Author(s):  
Magda Ferreira ◽  
Maria Ogren ◽  
Joana N. R. Dias ◽  
Marta Silva ◽  
Solange Gil ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Private Investment ◽  
Therapeutic Index ◽  
Multidrug Resistant ◽  
Current Treatment ◽  
Delivery Systems ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Antimicrobial Drugs

Antimicrobial drugs are key tools to prevent and treat bacterial infections. Despite the early success of antibiotics, the current treatment of bacterial infections faces serious challenges due to the emergence and spread of resistant bacteria. Moreover, the decline of research and private investment in new antibiotics further aggravates this antibiotic crisis era. Overcoming the complexity of antimicrobial resistance must go beyond the search of new classes of antibiotics and include the development of alternative solutions. The evolution of nanomedicine has allowed the design of new drug delivery systems with improved therapeutic index for the incorporated compounds. One of the most promising strategies is their association to lipid-based delivery (nano)systems. A drug’s encapsulation in liposomes has been demonstrated to increase its accumulation at the infection site, minimizing drug toxicity and protecting the antibiotic from peripheral degradation. In addition, liposomes may be designed to fuse with bacterial cells, holding the potential to overcome antimicrobial resistance and biofilm formation and constituting a promising solution for the treatment of potential fatal multidrug-resistant bacterial infections, such as methicillin resistant Staphylococcus aureus. In this review, we aim to address the applicability of antibiotic encapsulated liposomes as an effective therapeutic strategy for bacterial infections.

Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria

2017 ◽  
Vol 61 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Mohsen Arzanlou ◽  
Wern Chern Chai ◽  
Henrietta Venter
Keyword(s):  
Antimicrobial Resistance ◽  
Molecular Mechanisms ◽  
Resistance Mechanisms ◽  
Stress Conditions ◽  
Gram Negative Bacteria ◽  
Mechanisms Of Resistance ◽  
Intrinsic Resistance ◽  
Antimicrobial Drugs ◽  
Gram Negative ◽  
Gram Negative Organisms

Gram-negative bacteria are responsible for a large proportion of antimicrobial-resistant infections in humans and animals. Among this class of bacteria are also some of the most successful environmental organisms. Part of this success is their adaptability to a variety of different niches, their intrinsic resistance to antimicrobial drugs and their ability to rapidly acquire resistance mechanisms. These mechanisms of resistance are not exclusive and the interplay of several mechanisms causes high levels of resistance. In this review, we explore the molecular mechanisms underlying resistance in Gram-negative organisms and how these different mechanisms enable them to survive many different stress conditions.

scholarly journals Metabolites from Marine-Derived Fungi as Potential Antimicrobial Adjuvants

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 475
Author(s):  
Fernando Durães ◽  
Nikoletta Szemerédi ◽  
Decha Kumla ◽  
Madalena Pinto ◽  
Anake Kijjoa ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Efflux Pump ◽  
Fibroblast Cell ◽  
Resistance Mechanisms ◽  
Docking Studies ◽  
Mouse Fibroblast ◽  
Special Importance ◽  
Bacterial Cells ◽  
Antimicrobial Drugs ◽  
Promising Source

Marine-derived fungi constitute an interesting source of bioactive compounds, several of which exhibit antibacterial activity. These acquire special importance, considering that antimicrobial resistance is becoming more widespread. The overexpression of efflux pumps, capable of expelling antimicrobials out of bacterial cells, is one of the most worrisome mechanisms. There has been an ongoing effort to find not only new antimicrobials, but also compounds that can block resistance mechanisms which can be used in combination with approved antimicrobial drugs. In this work, a library of nineteen marine natural products, isolated from marine-derived fungi of the genera Neosartorya and Aspergillus, was evaluated for their potential as bacterial efflux pump inhibitors as well as the antimicrobial-related mechanisms, such as inhibition of biofilm formation and quorum-sensing. Docking studies were performed to predict their efflux pump action. These compounds were also tested for their cytotoxicity in mouse fibroblast cell line NIH/3T3. The results obtained suggest that the marine-derived fungal metabolites are a promising source of compounds with potential to revert antimicrobial resistance and serve as an inspiration for the synthesis of new antimicrobial drugs.

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.

scholarly journals Crumbling the Castle: Targeting DNABII Proteins for Collapsing Bacterial Biofilms as a Therapeutic Approach to Treat Disease and Combat Antimicrobial Resistance

Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 104
Author(s):  
James V. Rogers ◽  
Veronica L. Hall ◽  
Charles C. McOsker
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Defense Mechanism ◽  
Treatment Options ◽  
Bacterial Biofilms ◽  
Host Immune System ◽  
New Antibiotics ◽  
Financial Burdens ◽  
Global Threat

Antimicrobial resistance (AMR) is a concerning global threat that, if not addressed, could lead to increases in morbidity and mortality, coupled with societal and financial burdens. The emergence of AMR bacteria can be attributed, in part, to the decreased development of new antibiotics, increased misuse and overuse of existing antibiotics, and inadequate treatment options for biofilms formed during bacterial infections. Biofilms are complex microbiomes enshrouded in a self-produced extracellular polymeric substance (EPS) that is a primary defense mechanism of the resident microorganisms against antimicrobial agents and the host immune system. In addition to the physical protective EPS barrier, biofilm-resident bacteria exhibit tolerance mechanisms enabling persistence and the establishment of recurrent infections. As current antibiotics and therapeutics are becoming less effective in combating AMR, new innovative technologies are needed to address the growing AMR threat. This perspective article highlights such a product, CMTX-101, a humanized monoclonal antibody that targets a universal component of bacterial biofilms, leading to pathogen-agnostic rapid biofilm collapse and engaging three modes of action—the sensitization of bacteria to antibiotics, host immune enablement, and the suppression of site-specific tissue inflammation. CMTX-101 is a new tool used to enhance the effectiveness of existing, relatively inexpensive first-line antibiotics to fight infections while promoting antimicrobial stewardship.

scholarly journals Antimicrobial Synergy of Silver-Platinum Nanohybrids With Antibiotics

2021 ◽  
Vol 11 ◽  
Author(s):  
Bansi Ranpariya ◽  
Gayatri Salunke ◽  
Srikanta Karmakar ◽  
Kaushik Babiya ◽  
Santosh Sutar ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Infections ◽  
Bacterial Biofilm ◽  
Antimicrobial Drugs ◽  
Mortality And Morbidity ◽  
Green Route ◽  
Antimicrobial Synergy ◽  
First Time ◽  
Tuber Extract ◽  
Powerful Strategy

Various bacterial pathogens are responsible for nosocomial infections resulting in critical pathophysiological conditions, mortality, and morbidity. Most of the bacterial infections are associated with biofilm formation, which is resistant to the available antimicrobial drugs. As a result, novel bactericidal agents need to be fabricated, which can effectively combat the biofilm-associated bacterial infections. Herein, for the first time we report the antimicrobial and antibiofilm properties of silver-platinum nanohybrids (AgPtNHs), silver nanoparticles (AgNPs), and platinum nanoparticles (PtNPs) against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The AgPtNHs were synthesized by a green route using Dioscorea bulbifera tuber extract at 100°C for 5 h. The AgPtNHs ranged in size from 20 to 80 nm, with an average of ∼59 nm. AgNPs, PtNPs, and AgPtNHs showed a zeta potential of −14.46, −1.09, and −11.39 mV, respectively. High antimicrobial activity was observed against P. aeruginosa and S. aureus and AgPtNHs exhibited potent antimicrobial synergy in combination with antibiotics such as streptomycin, rifampicin, chloramphenicol, novobiocin, and ampicillin up to variable degrees. Interestingly, AgPtNHs could inhibit bacterial biofilm formation significantly. Hence, co-administration of AgPtNHs and antibiotics may serve as a powerful strategy to treat bacterial infections.

scholarly journals A Dose-Response Study of Antibiotic Resistance inPseudomonas aeruginosa Biofilms

2000 ◽  
Vol 44 (3) ◽  
pp. 640-646 ◽  
Author(s):  
Alexei Brooun ◽  
Songhua Liu ◽  
Kim Lewis
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Molecular Mechanisms ◽  
Bacterial Biofilms ◽  
Bacterial Cells ◽  
Planktonic Cells ◽  
Dose Response Study ◽  
Dose Dependent ◽  
Very High

ABSTRACT Bacterial biofilms show enormous levels of antibiotic resistance, but little is known about the underlying molecular mechanisms. Multidrug resistance pumps (MDRs) are responsible for the extrusion of chemically unrelated antimicrobials from the bacterial cell. Contribution of the MDR-mediated efflux to antibiotic resistance ofPseudomonas aeruginosa biofilms was examined by using strains overexpressing and lacking the MexAB-OprM pump. Resistance ofP. aeruginosa biofilms to ofloxacin was dependent on the expression of MexAB-OprM but only in the low concentration range. Unexpectedly, biofilm resistance to ciprofloxacin, another substrate of MexAB-OprM, did not depend on the presence of this pump. Dose-dependent killing indicated the presence of a small “superresistant” cell fraction. This fraction was primarily responsible for very high resistance of P. aeruginosa biofilms to quinolones. Bacterial cells recovered from a biofilm and tested under nongrowing conditions with tobramycin exhibited higher resistance levels than planktonic cells but lower levels than cells of an intact biofilm.

scholarly journals Laboratory based antimicrobial resistance surveillance for Pseudomonas aeruginosa blood isolates from South Africa

2018 ◽  
Vol 12 (08) ◽  
pp. 616-624
Author(s):  
Ashika Singh-Moodley ◽  
Adriano Duse ◽  
Preneshni Naicker ◽  
Ranmini Kularatne ◽  
Trusha Nana ◽  
...  
Keyword(s):  
South Africa ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Bacterial Infections ◽  
Treatment Guidelines ◽  
Resistance Mechanisms ◽  
Multi Drug Resistance ◽  
Hospital Treatment ◽  
Baseline Information

Introduction: Antimicrobial resistant bacterial infections are widespread globally and increases in antimicrobial resistance presents a major threat to public health. Pseudomonas aeruginosa is an opportunistic healthcare-associated pathogen with high rates of morbidity and mortality and an extensive range of resistance mechanisms. This study describes the antibiotic susceptibility profiles of P. aeruginosa isolates from patients with bacteraemia submitted by sentinel laboratories in South Africa from 2014 to 2015. Methodology: Organism identification and antimicrobial susceptibility testing were done using automated systems. Molecular methods were used to detect common resistance genes and mechanisms. Results: Overall the susceptibility was high for all antibiotics tested with a decrease over the two-year period. There was no change in the MIC50 and MIC90 breakpoints for all antibiotics from 2014 to 2015. The MIC50 was within the susceptible breakpoint range for most antibiotics and the MIC90 was within the susceptible breakpoint range for colistin only. Phenotypically carbapenem non-susceptible isolates harboured the following plasmid-mediated genes: blaVIM (n = 81, 12%) and blaGES (n = 6, 0.9%); blaNDM (n = 4, 0.6%) and blaOXA-48 and variants (n = 3, 0.45%). Porin deletions were observed in one meropenem non-susceptible isolate only, and multi-drug resistance efflux pumps were expressed in the majority of the non-susceptible isolates investigated. BlaVEB-1, blaIMP and blaKPC were not detected. Conclusion: The prevalence of resistance to commonly used antibacterial agents was low for P. aeruginosa isolates and similarly, tested resistance mechanisms were detected in a relatively small proportion of isolates. Findings in this study represent baseline information for understanding antimicrobial susceptibility patterns in P. aeruginosa isolates from blood. Our surveillance report may assist in contributing to hospital treatment guidelines.

scholarly journals Inactivation efficacy of atmospheric air plasma and airborne acoustic ultrasound against bacterial biofilms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Apurva D. Patange ◽  
Jeremy C. Simpson ◽  
James F. Curtin ◽  
Catherine M. Burgess ◽  
P. J. Cullen ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Primary Role ◽  
Bacterial Cells ◽  
Bacterial Inactivation ◽  
Air Plasma ◽  
Atmospheric Air ◽  
Environment And Health ◽  
Ultrasound Technology

AbstractBiofilms are complex microbial communities that present serious contamination risks to our environment and health. In this study, atmospheric air plasma and airborne acoustic ultrasound technology were applied to inactivate Escherichia coli and Listeria innocua biofilms. Both technologies were efficient in controlling, or completely inactivating, the target bacterial biofilms. Viability and metabolic assays, along with microscopy analysis, revealed that atmospheric air plasma and airborne acoustic ultrasound damaged both the bacterial biofilm cells and its structural integrity. Scanning electron microscopy images highlighted the disruption of the biofilms and pore formation in bacterial cells exposed to both the plasma and acoustic treatments. Elevated reactive oxygen and nitrogen species in bacterial cells treated with atmospheric air plasma, demonstrated their primary role in the observed bacterial inactivation process. Our findings provide potential antimicrobial strategies to combat bacterial biofilms in the food and healthcare sectors.

scholarly journals Chitosan Oligosaccharides Coupling Inhibits Bacterial Biofilm-Related Antibiotic Resistance against Florfenicol

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 6043
Author(s):  
Xianghua Yuan ◽  
Jing Liu ◽  
Ruilian Li ◽  
Junlin Zhou ◽  
Jinhua Wei ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Bacterial Infections ◽  
Bacterial Biofilm ◽  
Bacterial Biofilms ◽  
Gram Negative Bacteria ◽  
Planktonic Cells ◽  
Gram Negative ◽  
Chitosan Oligosaccharides ◽  
Spectrum Activity ◽  
Broad Spectrum Activity

The formation of bacterial biofilms has increased the resistance of bacteria to various environmental factors and is tightly associated with many persistent and chronic bacterial infections. Herein we design a strategy conjugating florfenicol, an antibiotic commonly used in the treatment of streptococcus, with the antimicrobial biomaterial, chitosan oligosaccharides. The results demonstrated that the florfenicol-COS conjugate (F-COS) efficiently eradicated the mature Streptococcus hyovaginalis biofilm, apparently inhibiting drug resistance to florfenicol. A quantity of 250 μg/mL F-COS showed effective inhibitory activity against planktonic cells and biofilm of the bacteria, and a 4-fold improvement of the F-COS compared to unmodified florfenicol was observed. Furthermore, the conjugate showed a broad-spectrum activity against both Gram-positive and Gram-negative bacteria. It suggested that F-COS might have a potential for application in the treatment of biofilm-related infections.

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