scholarly journals Low-level predation by lytic phage phiIPLA-RODI promotes biofilm formation and triggers the stringent response in Staphylococcus aureus

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Lucía Fernández ◽  
Silvia González ◽  
Ana Belén Campelo ◽  
Beatriz Martínez ◽  
Ana Rodríguez ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Stringent Response ◽  
Lytic Phage ◽  
Low Level

scholarly journals Low Levels of β-Lactam Antibiotics Induce Extracellular DNA Release and Biofilm Formation in Staphylococcus aureus

mBio ◽  
2012 ◽  
Vol 3 (4) ◽  
Author(s):  
Jeffrey B. Kaplan ◽  
Era A. Izano ◽  
Prerna Gopal ◽  
Michael T. Karwacki ◽  
Sangho Kim ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Extracellular Dna ◽  
Human Pathogen ◽  
Methicillin Resistant ◽  
Content Type ◽  
Low Level ◽  
Dna Release ◽  
Low Levels

ABSTRACTSubminimal inhibitory concentrations of antibiotics have been shown to induce bacterial biofilm formation. Few studies have investigated antibiotic-induced biofilm formation inStaphylococcus aureus, an important human pathogen. Our goal was to measureS. aureusbiofilm formation in the presence of low levels of β-lactam antibiotics. Fifteen phylogenetically diverse methicillin-resistantStaphylococcus aureus(MRSA) and methicillin-sensitiveS. aureus(MSSA) strains were employed. Methicillin, ampicillin, amoxicillin, and cloxacillin were added to cultures at concentrations ranging from 0× to 1× MIC. Biofilm formation was measured in 96-well microtiter plates using a crystal violet binding assay. Autoaggregation was measured using a visual test tube settling assay. Extracellular DNA was quantitated using agarose gel electrophoresis. All four antibiotics induced biofilm formation in some strains. The amount of biofilm induction was as high as 10-fold and was inversely proportional to the amount of biofilm produced by the strain in the absence of antibiotics. MRSA strains of lineages USA300, USA400, and USA500 exhibited the highest levels of methicillin-induced biofilm induction. Biofilm formation induced by low-level methicillin was inhibited by DNase. Low-level methicillin also induced DNase-sensitive autoaggregation and extracellular DNA release. The biofilm induction phenotype was absent in a strain deficient in autolysin (atl). Our findings demonstrate that subminimal inhibitory concentrations of β-lactam antibiotics significantly induce autolysin-dependent extracellular DNA release and biofilm formation in some strains ofS. aureus.IMPORTANCEThe widespread use of antibiotics as growth promoters in agriculture may expose bacteria to low levels of the drugs. The aim of this study was to investigate the effects of low levels of antibiotics on bacterial autoaggregation and biofilm formation, two processes that have been shown to foster genetic exchange and antibiotic resistance. We found that low levels of β-lactam antibiotics, a class commonly used in both clinical and agricultural settings, caused significant autoaggregation and biofilm formation by the important human pathogenStaphylococcus aureus. Both processes were dependent on cell lysis and release of DNA into the environment. The effect was most pronounced among multidrug-resistant strains known as methicillin-resistantS. aureus(MRSA). These results may shed light on the recalcitrance of some bacterial infections to antibiotic treatment in clinical settings and the evolution of antibiotic-resistant bacteria in agricultural settings.

Biological Evaluation of Selected 1,2,3-triazole Derivatives as Antibacterial and Antibiofilm Agents

2020 ◽  
Vol 20 (24) ◽  
pp. 2186-2191
Author(s):  
Lialyz Soares Pereira André ◽  
Renata Freire Alves Pereira ◽  
Felipe Ramos Pinheiro ◽  
Aislan Cristina Rheder Fagundes Pascoal ◽  
Vitor Francisco Ferreira ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Public Health Problem ◽  
Biological Evaluation ◽  
Major Public Health Problem ◽  
Community Environments ◽  
Scanning Electron

Background: Resistance to antimicrobial agents is a major public health problem, being Staphylococcus aureus prevalent in infections in hospital and community environments and, admittedly, related to biofilm formation in biotic and abiotic surfaces. Biofilms form a complex and structured community of microorganisms surrounded by an extracellular matrix adhering to each other and to a surface that gives them even more protection from and resistance against the action of antimicrobial agents, as well as against host defenses. Methods: Aiming to control and solve these problems, our study sought to evaluate the action of 1,2,3- triazoles against a Staphylococcus aureus isolate in planktonic and in the biofilm form, evaluating the activity of this triazole through Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. We have also performed cytotoxic evaluation and Scanning Electron Microscopy (SEM) of the biofilms under the treatment of the compound. The 1,2,3-triazole DAN 49 showed bacteriostatic and bactericidal activity (MIC and MBC 128 μg/mL). In addition, its presence interfered with the biofilm formation stage (1/2 MIC, p <0.000001) and demonstrated an effect on young preformed biofilm (2 MICs, p <0.05). Results: Scanning Electron Microscopy images showed a reduction in the cell population and the appearance of deformations on the surface of some bacteria in the biofilm under treatment with the compound. Conclusion: Therefore, it was possible to conclude the promising anti-biofilm potential of 1,2,3-triazole, demonstrating the importance of the synthesis of new compounds with biological activity.

scholarly journals Successful Treatment of Staphylococcus aureus Prosthetic Joint Infection with Bacteriophage Therapy

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1182
Author(s):  
Claudia Ramirez-Sanchez ◽  
Francis Gonzales ◽  
Maureen Buckley ◽  
Biswajit Biswas ◽  
Matthew Henry ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Prosthetic Joint Infection ◽  
Joint Infection ◽  
Multidrug Resistant ◽  
Successful Outcome ◽  
Prolonged Treatment ◽  
Lytic Phage ◽  
Bacteriophage Therapy ◽  
Prosthetic Joint ◽  
Knee Joint Infection

Successful joint replacement is a life-enhancing procedure with significant growth in the past decade. Prosthetic joint infection occurs rarely; it is a biofilm-based infection that is poorly responsive to antibiotic alone. Recent interest in bacteriophage therapy has made it possible to treat some biofilm-based infections, as well as those caused by multidrug-resistant pathogens, successfully when conventional antibiotic therapy has failed. Here, we describe the case of a 61-year-old woman who was successfully treated after a second cycle of bacteriophage therapy administered at the time of a two-stage exchange procedure for a persistent methicillin-sensitive Staphylococcus aureus (MSSA) prosthetic knee-joint infection. We highlight the safety and efficacy of both intravenous and intra-articular infusions of bacteriophage therapy, a successful outcome with a single lytic phage, and the development of serum neutralization with prolonged treatment.

scholarly journals Paracetamol modulates biofilm formation in Staphylococcus aureus clonal complex 8 strains

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andi R. Sultan ◽  
Kirby R. Lattwein ◽  
Nicole A. Lemmens-den Toom ◽  
Susan V. Snijders ◽  
Klazina Kooiman ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Fluorescent Protein ◽  
Clonal Complex ◽  
Regulatory Pathways ◽  
Immune Modulator ◽  
Viability Assay ◽  
Analgesic Agents ◽  
Green Fluorescent

AbstractStaphylococcus aureus biofilms are a major problem in modern healthcare due to their resistance to immune system defenses and antibiotic treatments. Certain analgesic agents are able to modulate S. aureus biofilm formation, but currently no evidence exists if paracetamol, often combined with antibiotic treatment, also has this effect. Therefore, we aimed to investigate if paracetamol can modulate S. aureus biofilm formation. Considering that certain regulatory pathways for biofilm formation and virulence factor production by S. aureus are linked, we further investigated the effect of paracetamol on immune modulator production. The in vitro biofilm mass of 21 S. aureus strains from 9 genetic backgrounds was measured in the presence of paracetamol. Based on biofilm mass quantity, we further investigated paracetamol-induced biofilm alterations using a bacterial viability assay combined with N-Acetylglucosamine staining. Isothermal microcalorimetry was used to monitor the effect of paracetamol on bacterial metabolism within biofilms and green fluorescent protein (GFP) promoter fusion technology for transcription of staphylococcal complement inhibitor (SCIN). Clinically relevant concentrations of paracetamol enhanced biofilm formation particularly among strains belonging to clonal complex 8 (CC8), but had minimal effect on S. aureus planktonic growth. The increase of biofilm mass can be attributed to the marked increase of N-Acetylglucosamine containing components of the extracellular matrix, presumably polysaccharide intercellular adhesion. Biofilms of RN6390A (CC8) showed a significant increase in the immune modulator SCIN transcription during co-incubation with low concentrations of paracetamol. Our data indicate that paracetamol can enhance biofilm formation. The clinical relevance needs to be further investigated.

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