scholarly journals Biofilm Formation of Multidrug-Resistant MRSA Strains Isolated from Different Types of Human Infections

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 970
Author(s):  
Vanessa Silva ◽  
Luciana Almeida ◽  
Vânia Gaio ◽  
Nuno Cerca ◽  
Vera Manageiro ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Confocal Scanning Laser Microscopy ◽  
Chronic Infections ◽  
Xtt Assay ◽  
Different Types ◽  
Confocal Scanning Laser ◽  
Mrsa Strains ◽  
Conventional Antibiotics ◽  
Human Infections

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main pathogens causing chronic infections, mainly due to its capacity to form biofilms. However, the mechanisms underlying the biofilm formation of MRSA strains from different types of human infections are not fully understood. MRSA strains isolated from distinct human infections were characterized aiming to determine their biofilm-forming capacity, the biofilm resistance to conventional antibiotics and the prevalence of biofilm-related genes, including, icaA, icaB, icaC, icaD, fnbA, fnbB, clfA, clfB, cna, eno, ebpS, fib and bbp. Eighty-three clinical MRSA strains recovered from bacteremia episodes, osteomyelitis and diabetic foot ulcers were used. The biofilm-forming capacity was evaluated by the microtiter biofilm assay and the biofilm structure was analyzed via confocal scanning laser microscopy. The antimicrobial susceptibility of 24-h-old biofilms was assessed against three antibiotics and the biomass reduction was measured. The metabolic activity of biofilms was evaluated by the XTT assay. The presence of biofilm-related genes was investigated by whole-genome sequencing and by PCR. Despite different intensities, all strains showed the capacity to form biofilms. Most strains had also a large number of biofilm-related genes. However, strains isolated from osteomyelitis showed a lower capacity to form biofilms and also a lower prevalence of biofilm-associated genes. There was a significant reduction in the biofilm biomass of some strains tested against antibiotics. Our results provide important information on the biofilm-forming capacity of clinical MRSA strains, which may be essential to understand the influence of different types of infections on biofilm production and chronic infections.

scholarly journals Characterization of the Poly-β-1,6-N-Acetylglucosamine Polysaccharide Component of Burkholderia Biofilms

2011 ◽  
Vol 77 (23) ◽  
pp. 8303-8309 ◽  
Author(s):  
Nandadeva Yakandawala ◽  
Purushottam V. Gawande ◽  
Karen LoVetri ◽  
Silvia T. Cardona ◽  
Tony Romeo ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Burkholderia Cepacia ◽  
Burkholderia Cenocepacia ◽  
Confocal Scanning Laser Microscopy ◽  
Wild Type ◽  
Chronic Infections ◽  
Content Type ◽  
Burkholderia Vietnamiensis ◽  
Test Organisms ◽  
Confocal Scanning Laser

ABSTRACTWe demonstrated the production of poly-β-1,6-N-acetylglucosamine (PNAG) polysaccharide in the biofilms ofBurkholderia multivorans,Burkholderia vietnamiensis,Burkholderia ambifaria,Burkholderia cepacia, andBurkholderia cenocepaciausing an immunoblot assay for PNAG. These results were confirmed by further studies, which showed that the PNAG hydrolase, dispersin B, eliminated immunoreactivity of extracts from the species that were tested (B. cenocepaciaandB. multivorans). Dispersin B also inhibited biofilm formation and dispersed preformed biofilms ofBurkholderiaspecies. These results imply a role for PNAG in the maintenance ofBurkholderiabiofilm integrity. While PNAG was present in biofilms of all of the wild-type test organisms, a ΔpgaBCmutant ofB. multivorans(Mu5) produced no detectable PNAG, indicating that these genes are needed forBurkholderiaPNAG formation. Furthermore, restoration of PNAG production in PNAG negativeE. coliTRXWMGΔC (ΔpgaC) by complementation withB. multivorans pgaBCDconfirmed the involvement of these genes inBurkholderiaPNAG production. While the confocal scanning laser microscopy of untreated wild-typeB. multivoransshowed thick, multilayered biofilm, Mu5 and dispersin B-treated wild-type biofilms were thin, poorly developed, and disrupted, confirming the involvement of PNAG inB. multivoransbiofilm formation. Thus, PNAG appears to be an important component ofBurkholderiabiofilms, potentially contributing to its resistance to multiple antibiotics and persistence during chronic infections, including cystic fibrosis-associated infection.

scholarly journals Structurally nanoengineered antimicrobial peptide polymers: design, synthesis and biomedical applications

2021 ◽  
Vol 37 (8) ◽  
Author(s):  
Ronisha Ramamurthy ◽  
Chetan H. Mehta ◽  
Usha Y. Nayak
Keyword(s):  
Health Care ◽  
Antimicrobial Peptide ◽  
Biomedical Applications ◽  
Multidrug Resistant ◽  
Chronic Infections ◽  
Synthesis Mechanism ◽  
Design Synthesis ◽  
Global Health Care ◽  
Conventional Antibiotics ◽  
Peptide Polymers

Abstract Antimicrobial resistance not only increases the contagiousness of infectious diseases but also a threat for the future as it is one of the health care concern around the globe. Conventional antibiotics are unsuccessful in combating chronic infections caused by multidrug-resistant (MDR) bacteria, therefore it is important to design and develop novel strategies to tackle this problems. Among various novel strategies, Structurally Nanoengineered Antimicrobial Peptide Polymers (SNAPPs) have been introduced in recent years to overcome this global health care issue and they are found to be more efficient in their performance. Many facile methods are adapted to synthesize complex SNAPPs with required dimensions and unique functionalities. Their unique characteristics and remarkable properties have been exploited for their immense applications in various fields including biomedicine, targeting therapies, gene delivery, bioimaging, and many more. This review article deals with its background, design, synthesis, mechanism of action, and wider applications in various fields of SNAPPs. Graphic abstract

scholarly journals Activity of Debio1452, a FabI Inhibitor with Potent Activity against Staphylococcus aureus and Coagulase-Negative Staphylococcus spp., Including Multidrug-Resistant Strains

2015 ◽  
Vol 59 (5) ◽  
pp. 2583-2587 ◽  
Author(s):  
Robert K. Flamm ◽  
Paul R. Rhomberg ◽  
Nachum Kaplan ◽  
Ronald N. Jones ◽  
David J. Farrell
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Fatty Acid Biosynthesis ◽  
Multidrug Resistant ◽  
Coagulase Negative Staphylococcus ◽  
Significant Activity ◽  
Coagulase Negative Staphylococci ◽  
Content Type ◽  
Mrsa Strains ◽  
Human Infections

ABSTRACTStaphylococcus aureusand coagulase-negative staphylococci (CoNS) are responsible for a wide variety of human infections. The investigational antibacterial Debio1450 (previously AFN-1720), a prodrug of Debio1452 (previously AFN-1252), specifically targets staphylococci without significant activity against other Gram-positive or Gram-negative species. Debio1452 inhibits FabI, an enzyme critical to fatty acid biosynthesis in staphylococci. The activity of Debio1452 against CoNS, methicillin-susceptibleS. aureus(MSSA), and methicillin-resistantS. aureus(MRSA), including significant clones, was determined. A globally diverse collection of 574 patient isolates from 35 countries was tested that included CoNS (6 species, 103 strains), MSSA (154 strains), MRSA (163 strains), and molecularly characterized strains (includingspa-typed MRSA clones; 154 strains). The isolates were tested for susceptibility by CLSI broth microdilution methods against Debio1452 and 10 comparators. The susceptibility rates for the comparators were determined using CLSI and EUCAST breakpoint criteria. AllS. aureusand CoNS strains were inhibited by Debio1452 concentrations of ≤0.12 and ≤0.5 μg/ml, respectively. The MIC50s for MSSA, MRSA, and molecularly characterized MRSA strains were 0.004 μg/ml, and the MIC90s ranged from 0.008 to 0.03 μg/ml. The MICs were higher for the CoNS isolates (MIC50/90, 0.015/0.12 μg/ml). AmongS. aureusstrains, resistance was common for erythromycin (61.6%), levofloxacin (49.0%), clindamycin (27.6%), tetracycline (15.7%), and trimethoprim-sulfamethoxazole (7.0%). Debio1452 demonstrated potent activity against MSSA, MRSA, and CoNS. Debio1452 showed significantly greater activity overall (MIC50, 0.004 μg/ml) than the other agents tested against these staphylococcal species, which included dominant MRSA clones and strains resistant to currently utilized antimicrobial agents.

scholarly journals Antimicrobial and Antibiofilm Peptides

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 652 ◽  
Author(s):  
Angela Di Somma ◽  
Antonio Moretta ◽  
Carolina Canè ◽  
Arianna Cirillo ◽  
Angela Duilio
Keyword(s):  
Antimicrobial Peptides ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibiofilm Activity ◽  
Chronic Infections ◽  
Planktonic Bacteria ◽  
Hostile Environments

The increasing onset of multidrug-resistant bacteria has propelled microbiology research towards antimicrobial peptides as new possible antibiotics from natural sources. Antimicrobial peptides are short peptides endowed with a broad range of activity against both Gram-positive and Gram-negative bacteria and are less prone to trigger resistance. Besides their activity against planktonic bacteria, many antimicrobial peptides also show antibiofilm activity. Biofilms are ubiquitous in nature, having the ability to adhere to virtually any surface, either biotic or abiotic, including medical devices, causing chronic infections that are difficult to eradicate. The biofilm matrix protects bacteria from hostile environments, thus contributing to the bacterial resistance to antimicrobial agents. Biofilms are very difficult to treat, with options restricted to the use of large doses of antibiotics or the removal of the infected device. Antimicrobial peptides could represent good candidates to develop new antibiofilm drugs as they can act at different stages of biofilm formation, on disparate molecular targets and with various mechanisms of action. These include inhibition of biofilm formation and adhesion, downregulation of quorum sensing factors, and disruption of the pre-formed biofilm. This review focuses on the proprieties of antimicrobial and antibiofilm peptides, with a particular emphasis on their mechanism of action, reporting several examples of peptides that over time have been shown to have activity against biofilm.

scholarly journals Applications of Personalised Phage Therapy highlighting the importance of Bacteriophage Banks against Emerging Antimicrobial Resistance

2020 ◽  
Vol 5 (4) ◽  
pp. 305-314
Author(s):  
Taruna Anand ◽  
Nitin Virmani ◽  
Bidhan C Bera ◽  
Rajesh K Vaid ◽  
Ashok Kumar ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Phage Therapy ◽  
Multidrug Resistant ◽  
Main Stream ◽  
Chronic Infections ◽  
Custom Made ◽  
Instant Availability ◽  
Human Infections ◽  
Therapeutic Alternatives ◽  
Continuous Use

Emerging antibiotic resistance is one of the most important microbiological issues of the 21st century. This poses a query regarding the future use of antibiotics and availability of other promising therapeutic alternatives. The awareness about antibiotic misuse has improved insufficiently and is evident by the increased incidences of multidrug resistant infections globally. Amongst different antibacterial therapeutic approaches phage therapy has created a niche of its own due to continuous use for treatment of human infections in Eastern Europe. Synergistic compounds along with phages have also been proposed as a better alternative compared to antibiotics or phage alone for treatment of chronic cases and seriously debilitating diseases. As such, why not allow custom made phage therapy for treatment of chronic infections? However, the success of phage therapy will depend upon instant availability of characterised bacteriophages from bacteriophage banks which may serve as the major catalyst in bringing Phage Therapy to main stream treatment alternatives or in combination therapy at least. In the current article we present a glimpse of comprehensive approach about utility of bacteriophage banks and further present personalised phage therapy in a synergistic role with antibiotics to overcome emerging antimicrobial resistance.

scholarly journals Environmental factors modulate biofilm formation by Staphylococcus aureus

2020 ◽  
Vol 103 (1) ◽  
pp. 003685041989865
Author(s):  
Ying Liu ◽  
Jiang Zhang ◽  
Yinduo Ji
Keyword(s):  
Staphylococcus Aureus ◽  
Environmental Factors ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Treatment Options ◽  
Multiple Drug ◽  
Chronic Infections ◽  
Methicillin Resistant ◽  
Multiple Drug Resistant ◽  
Human Infections

Biofilm formation on indwelling medical devices represents an exclusive evasion mechanism for many pathogenic bacteria to establish chronic infections. Staphylococcus aureus is one of the major bacterial pathogens that are able to induce both animal and human infections. The continued emergence of multiple drug-resistant S. aureus, especially methicillin-resistant S. aureus, is problematic due to limited treatment options. Biofilm formation by S. aureus complicates the treatment of methicillin-resistant S. aureus infections. Therefore, elucidating the mechanisms of biofilm formation in this pathogen is important for the development of alternative therapeutic strategies. Various environmental and genetic factors contribute to biofilm formation. In this review, we address the environmental factors and discuss how they affect biofilm formation by S. aureus.

scholarly journals Polyphenols Inhibit Candida albicans and Streptococcus mutans Biofilm Formation

2019 ◽  
Vol 7 (2) ◽  
pp. 42 ◽  
Author(s):  
Yosi Farkash ◽  
Mark Feldman ◽  
Isaac Ginsburg ◽  
Doron Steinberg ◽  
Miriam Shalish
Keyword(s):  
Candida Albicans ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Inhibitory Effect ◽  
Confocal Scanning Laser Microscopy ◽  
Total Biomass ◽  
Biofilm Inhibition ◽  
Confocal Scanning ◽  
Confocal Scanning Laser ◽  
Biofilm Development

Background: Streptococcus mutans (S. mutans) and Candida albicans (C. albicans) are two major contributors to dental caries. They have a symbiotic relationship, allowing them to create an enhanced biofilm. Our goal was to examine whether two natural polyphenols (Padma hepaten (PH) and a polyphenol extraction from green tea (PPFGT)) could inhibit the caries-inducing properties of S. mutans and C. albicans. Methods: Co-species biofilms of S. mutans and C. albicans were grown in the presence of PH and PPFGT. Biofilm formation was tested spectrophotometrically. Exopolysaccharides (EPS) secretion was quantified using confocal scanning laser microscopy. Biofilm development was also tested on orthodontic surfaces (Essix) to assess biofilm inhibition ability on such an orthodontic appliance. Results: PPFGT and PH dose-dependently inhibited biofilm formation without affecting the planktonic growth. We found a significant reduction in biofilm total biomass using 0.625 mg/mL PPFGT and 0.16 mg/mL PH. A concentration of 0.31 mg/mL PPFGT and 0.16 mg/mL PH inhibited the total cell growth by 54% and EPS secretion by 81%. A reduction in biofilm formation and EPS secretion was also observed on orthodontic PVC surfaces. Conclusions: The polyphenolic extractions PPFGT and PH have an inhibitory effect on S. mutans and C. albicans biofilm formation and EPS secretion.

scholarly journals Biofilm Formation by the Fungal PathogenCandida albicans: Development, Architecture, and Drug Resistance

2001 ◽  
Vol 183 (18) ◽  
pp. 5385-5394 ◽  
Author(s):  
Jyotsna Chandra ◽  
Duncan M. Kuhn ◽  
Pranab K. Mukherjee ◽  
Lois L. Hoyer ◽  
Thomas McCormick ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Molecular Mechanisms ◽  
Antifungal Resistance ◽  
Confocal Scanning Laser Microscopy ◽  
Heterogeneous Architecture ◽  
Scanning Laser Microscopy ◽  
Confocal Scanning ◽  
Confocal Scanning Laser ◽  
Developmental Phases ◽  
Polysaccharide Matrix

ABSTRACT Biofilms are a protected niche for microorganisms, where they are safe from antibiotic treatment and can create a source of persistent infection. Using two clinically relevant Candida albicans biofilm models formed on bioprosthetic materials, we demonstrated that biofilm formation proceeds through three distinct developmental phases. These growth phases transform adherent blastospores to well-defined cellular communities encased in a polysaccharide matrix. Fluorescence and confocal scanning laser microscopy revealed that C. albicans biofilms have a highly heterogeneous architecture composed of cellular and noncellular elements. In both models, antifungal resistance of biofilm-grown cells increased in conjunction with biofilm formation. The expression of agglutinin-like (ALS) genes, which encode a family of proteins implicated in adhesion to host surfaces, was differentially regulated between planktonic and biofilm-grown cells. The ability ofC. albicans to form biofilms contrasts sharply with that of Saccharomyces cerevisiae, which adhered to bioprosthetic surfaces but failed to form a mature biofilm. The studies described here form the basis for investigations into the molecular mechanisms of Candida biofilm biology and antifungal resistance and provide the means to design novel therapies for biofilm-based infections.

scholarly journals Pseudomonas aeruginosa Forms Biofilms in Acute Infection Independent of Cell-to-Cell Signaling

2007 ◽  
Vol 75 (8) ◽  
pp. 3715-3721 ◽  
Author(s):  
J. Andy Schaber ◽  
W. Jeffrey Triffo ◽  
Sang Jin Suh ◽  
Jeffrey W. Oliver ◽  
Mary Catherine Hastert ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Colonization ◽  
Acute Infection ◽  
Opportunistic Pathogen ◽  
Confocal Scanning Laser Microscopy ◽  
Chronic Infections ◽  
Signaling Mechanism ◽  
Confocal Scanning Laser

ABSTRACT Biofilms are bacterial communities residing within a polysaccharide matrix that are associated with persistence and antibiotic resistance in chronic infections. We show that the opportunistic pathogen Pseudomonas aeruginosa forms biofilms within 8 h of infection in thermally injured mice, demonstrating that biofilms contribute to bacterial colonization in acute infections as well. Using light, electron, and confocal scanning laser microscopy, P. aeruginosa biofilms were visualized within burned tissue surrounding blood vessels and adipose cells. Although quorum sensing (QS), a bacterial signaling mechanism, coordinates differentiation of biofilms in vitro, wild-type and QS-deficient P. aeruginosa strains formed similar biofilms in vivo. Our findings demonstrate that P. aeruginosa forms biofilms on specific host tissues independently of QS.

scholarly journals Citral modulates virulence factors in methicillin-resistant Staphylococcus aureus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hellen Braga Martins Oliveira ◽  
Nathan das Neves Selis ◽  
Beatriz Almeida Sampaio ◽  
Manoel Neres Santos Júnior ◽  
Suzi Pacheco de Carvalho ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Biofilm Formation ◽  
Production Capacity ◽  
High Morbidity ◽  
Methicillin Resistant ◽  
Biofilm Production ◽  
Initial Stage ◽  
Mrsa Strains ◽  
Conventional Antibiotics

AbstractMethicillin-resistant Staphylococcus aureus (MRSA) is responsible for high morbidity and mortality rates. Citral has been studied in the pharmaceutical industry and has shown antimicrobial activity. This study aimed to analyze the antimicrobial activity of citral in inhibiting biofilm formation and modulating virulence genes, with the ultimate goal of finding a strategy for treating infections caused by MRSA strains. Citral showed antimicrobial activity against MRSA isolates with minimum inhibitory concentration (MIC) values between 5 mg/mL (0.5%) and 40 mg/mL (4%), and minimum bactericidal concentration (MBC) values between 10 mg/mL (1%) and 40 mg/mL (4%). The sub-inhibitory dose was 2.5 mg/mL (0.25%). Citral, in an antibiogram, modulated synergistically, antagonistically, or indifferent to the different antibiotics tested. Prior to evaluating the antibiofilm effects of citral, we classified the bacteria according to their biofilm production capacity. Citral showed greater efficacy in the initial stage, and there was a significant reduction in biofilm formation compared to the mature biofilm. qPCR was used to assess the modulation of virulence factor genes, and icaA underexpression was observed in isolates 20 and 48. For icaD, seg, and sei, an increase was observed in the expression of ATCC 33,591. No significant differences were found for eta and etb. Citral could be used as a supplement to conventional antibiotics for MRSA infections.

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