scholarly journals New Adapted In Vitro Technology to Evaluate Biofilm Formation and Antibiotic Activity Using Live Imaging under Flow Conditions

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1746
Author(s):  
Cassandra Pouget ◽  
Catherine Dunyach-Remy ◽  
Alix Pantel ◽  
Sophie Schuldiner ◽  
Albert Sotto ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Cell Imaging ◽  
Chronic Wounds ◽  
Chronic Wound ◽  
Live Imaging ◽  
Bacterial Biofilm ◽  
Flow Conditions ◽  
Promising Tool ◽  
Reference Strains

The polymicrobial nature of biofilms and bacterial interactions inside chronic wounds are keys for the understanding of bacterial cooperation. The aim of this present study was to develop a technique to study and visualize biofilm in live imaging under flow conditions (Bioflux™ 200, Fluxion Biosciences). The BiofluxTM system was adapted using an in vitro chronic wound-like medium (CWM) that mimics the environment encountered in ulcers. Two reference strains of Staphylococcus aureus (Newman) and Pseudomonas aeruginosa (PAO1) were injected in the BiofluxTM during 24 h to 72 h in mono and coculture (ratio 1:1, bacteria added simultaneously) in the CWM vs. a control medium (BHI). The quantification of biofilm formation at each time was evaluated by inverted microscopy. After 72 h, different antibiotics (ceftazidime, imipenem, linezolid, oxacillin and vancomycin) at 1x MIC, 10x MIC and 100x MIC were administrated to the system after an automatic increase of the flow that mimicked a debridement of the wound surface. Biofilm studies highlighted that the two species, alone or associated, constituted a faster and thicker biofilm in the CWM compared to the BHI medium. The effect of antibiotics on mature or “debrided” biofilm indicated that some of the most clinically used antibiotic such as vancomycin or imipenem were not able to disrupt and reduce the biofilm biomass. The use of a life cell imaging with an in vitro CWM represents a promising tool to study bacterial biofilm and investigate microbial cooperation in a chronic wound context.

scholarly journals The In Vitro Ability of Klebsiella pneumoniae to Form Biofilm and the Potential of Various Compounds to Eradicate it from Urinary Catheters

Pathogens ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Monika Oleksy-Wawrzyniak ◽  
Adam Junka ◽  
Malwina Brożyna ◽  
Migdał Paweł ◽  
Bartłomiej Kwiek ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
High Frequency ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Flow Conditions ◽  
Urinary Infections ◽  
Efficient Reduction ◽  
Intraspecies Variability

Urinary infections related to the presence of bacterial biofilm on catheters are responsible for loss of patients’ health and, due to their high frequency of occurrence, generate a significant economic burden for hospitals. Klebsiella pneumoniae is a pathogen frequently isolated from this type of infection. In this study, using a cohesive set of techniques performed under stationary and flow conditions, we assessed the ability of 120 K. pneumoniae strains to form biofilm on various surfaces, including catheters, and evaluated the usefulness of clinically applied and experimental compounds to remove biofilm. The results of our study indicate the high impact of intraspecies variability with respect to K. pneumoniae biofilm formation and its susceptibility to antimicrobials and revealed the crucial role of mechanical flushing out of the biofilm from the catheter’s surface with use of locally active antimicrobials. Therefore, our work, although of in vitro character, may be considered an important step in the direction of efficient reduction of K. pneumoniae biofilm-related hospital infections associated with the presence of urine catheters.

scholarly journals Thiazole Analogues of the Marine Alkaloid Nortopsentin as Inhibitors of Bacterial Biofilm Formation

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 81
Author(s):  
Anna Carbone ◽  
Stella Cascioferro ◽  
Barbara Parrino ◽  
Daniela Carbone ◽  
Camilla Pecoraro ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Thiazole Derivatives ◽  
Gram Positive ◽  
Lead Compounds ◽  
New Class ◽  
Marked Selectivity ◽  
Global Threat ◽  
New Compounds ◽  
Reference Strains

Anti-virulence strategy is currently considered a promising approach to overcome the global threat of the antibiotic resistance. Among different bacterial virulence factors, the biofilm formation is recognized as one of the most relevant. Considering the high and growing percentage of multi-drug resistant infections that are biofilm-mediated, new therapeutic agents capable of counteracting the formation of biofilms are urgently required. In this scenario, a new series of 18 thiazole derivatives was efficiently synthesized and evaluated for its ability to inhibit biofilm formation against the Gram-positive bacterial reference strains Staphylococcus aureus ATCC 25923 and S. aureus ATCC 6538 and the Gram-negative strain Pseudomonas aeruginosa ATCC 15442. Most of the new compounds showed a marked selectivity against the Gram-positive strains. Remarkably, five compounds exhibited BIC50 values against S. aureus ATCC 25923 ranging from 1.0 to 9.1 µM. The new compounds, affecting the biofilm formation without any interference on microbial growth, can be considered promising lead compounds for the development of a new class of anti-virulence agents.

scholarly journals Vesicle-associatedPseudomonas aeruginosaleucine aminopeptidase modulates bacterial biofilms grown on host cellular substrates

2019 ◽  
Author(s):  
Caitlin N. Esoda ◽  
Meta J. Kuehn
Keyword(s):  
Biofilm Formation ◽  
Chronic Wounds ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Biofilm ◽  
Lung Epithelial ◽  
Coculture Model ◽  
Chronic Colonization ◽  
Bacterial Outer Membrane ◽  
Future Work

AbstractPseudomonas aeruginosa, known as one of the leading causes of morbidity and mortality in cystic fibrosis (CF) patients, secretes a variety of virulence-associated proteases. These enzymes have been shown to contribute significantly toP. aeruginosapathogenesis and biofilm formation in the chronic colonization of CF patient lungs, as well as playing a role in infections of the cornea, burn wounds and chronic wounds. Our lab has previously characterized a secretedP. aeruginosapeptidase, PaAP, that is highly expressed in chronic CF isolates. This leucine aminopeptidase is not only secreted solubly, it also associates with bacterial outer membrane vesicles (OMVs), structures known for their contribution to virulence mechanisms in a variety of Gram-negative species and one of the major components of the biofilm matrix. With this in mind, we hypothesized that PaAP may play a role inP. aeruginosabiofilm formation. Using a lung epithelial cell/bacterial biofilm coculture model, we show that PaAP deletion in a clinicalP. aeruginosabackground leads to increased early biofilm formation. We additionally found that only native vesicle-bound PaAP, as opposed to its soluble forms, could reconstitute the original PaAP-mediated inhibition phenotype, and that the PaAP-containing vesicles could disperse preformed biofilm microcolonies ofKlebsiella pneumoniae, another lung pathogen. These data provide the basis for future work into the mechanism behind PaAP-OMV mediated bacterial microcolony dispersal and the application of these findings to clinical anti-biofilm research.

scholarly journals Glycation of Host Proteins Increases Pathogenic Potential of Porphyromonas gingivalis

2021 ◽  
Vol 22 (21) ◽  
pp. 12084
Author(s):  
Michał Śmiga ◽  
John W. Smalley ◽  
Paulina Ślęzak ◽  
Jason L. Brown ◽  
Klaudia Siemińska ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Disease Process ◽  
Human Keratinocytes ◽  
Bacterial Biofilm ◽  
Pathogenic Potential ◽  
Glycated Proteins ◽  
Sds Page

The non-enzymatic addition of glucose (glycation) to circulatory and tissue proteins is a ubiquitous pathophysiological consequence of hyperglycemia in diabetes. Given the high incidence of periodontitis and diabetes and the emerging link between these conditions, it is of crucial importance to define the basic virulence mechanisms employed by periodontopathogens such as Porphyromonas gingivalis in mediating the disease process. The aim of this study was to determine whether glycated proteins are more easily utilized by P. gingivalis to stimulate growth and promote the pathogenic potential of this bacterium. We analyzed the properties of three commonly encountered proteins in the periodontal environment that are known to become glycated and that may serve as either protein substrates or easily accessible heme sources. In vitro glycated proteins were characterized using colorimetric assays, mass spectrometry, far- and near-UV circular dichroism and UV–visible spectroscopic analyses and SDS-PAGE. The interaction of glycated hemoglobin, serum albumin and type one collagen with P. gingivalis cells or HmuY protein was examined using spectroscopic methods, SDS-PAGE and co-culturing P. gingivalis with human keratinocytes. We found that glycation increases the ability of P. gingivalis to acquire heme from hemoglobin, mostly due to heme sequestration by the HmuY hemophore-like protein. We also found an increase in biofilm formation on glycated collagen-coated abiotic surfaces. We conclude that glycation might promote the virulence of P. gingivalis by making heme more available from hemoglobin and facilitating bacterial biofilm formation, thus increasing P. gingivalis pathogenic potential in vivo.

Endotracheal tubes coated with a broad-spectrum antibacterial ceragenin reduce bacterial biofilm in an in vitro bench top model

2021 ◽  
Author(s):  
María Consuelo Latorre ◽  
María Jesús Pérez-Granda ◽  
Paul B Savage ◽  
Beatriz Alonso ◽  
Pablo Martín-Rabadán ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
In Vitro Study ◽  
Bacterial Biofilm ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Endotracheal Tubes ◽  
Clinical Strains ◽  
Number Of Cells

Abstract Background Ventilator-associated pneumonia is one of the most common nosocomial infections, caused mainly by bacterial/fungal biofilm. Therefore, it is necessary to develop preventive strategies to avoid biofilm formation based on new compounds. Objectives We performed an in vitro study to compare the efficacy of endotracheal tubes (ETTs) coated with the ceragenin CSA-131 and that of uncoated ETTs against the biofilm of clinical strains of Pseudomonas aeruginosa (PA), Escherichia coli (EC) and Staphylococcus aureus (SA). Methods We applied an in vitro bench top model using coated and uncoated ETTs that were treated with three different clinical strains of PA, EC and SA for 5 days. After exposure to biofilm, ETTs were analysed for cfu count by culture of sonicate and total number of cells by confocal laser scanning microscopy. Results The median (IQR) cfu/mL counts of PA, EC and SA in coated and uncoated ETTs were, respectively, as follows: 1.00 × 101 (0.0–3.3 × 102) versus 3.32 × 109 (6.6 × 108–3.8 × 109), P < 0.001; 0.0 (0.0–5.4 × 103) versus 1.32 × 106 (2.3 × 103–5.0 × 107), P < 0.001; and 8.1 × 105 (8.5 × 101–1.4 × 109) versus 2.7 × 108 (8.6 × 106–1.6 × 1011), P = 0.058. The median (IQR) total number of cells of PA, EC and SA in coated and non-coated ETTs were, respectively, as follows: 11.0 [5.5–not applicable (NA)] versus 87.9 (60.5–NA), P = 0.05; 9.1 (6.7–NA) versus 62.6 (42.0–NA), P = 0.05; and 97.7 (94.6–NA) versus 187.3 (43.9–NA), P = 0.827. Conclusions We demonstrated significantly reduced biofilm formation in coated ETTs. However, the difference for SA was not statistically significant. Future clinical studies are needed to support our findings.

scholarly journals N-Acetyl-cysteine and Mechanisms Involved in Resolution of Chronic Wound Biofilm

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Xin Li ◽  
Jane Kim ◽  
Jiabin Wu ◽  
Alaa’ I Ahamed ◽  
Yinsheng Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
Bacterial Cell ◽  
Chronic Wounds ◽  
Chronic Wound ◽  
Diabetic Mouse ◽  
Bacterial Survival ◽  
Bacterial Cell Death ◽  
Carboxylic Groups ◽  
Acetyl Cysteine

Chronic wounds are a major global health problem with the presence of biofilm significantly contributing to wound chronicity. Current treatments are ineffective in resolving biofilm and simultaneously killing the bacteria; therefore, effective biofilm-resolving drugs are needed. We have previously shown that, together with α-tocopherol, N-acetyl-cysteine (NAC) significantly improves the healing of biofilm-containing chronic wounds, in a diabetic mouse model we developed, by causing disappearance of the bacteria and breakdown of the extracellular polymeric substance (EPS). We hypothesize that NAC creates a microenvironment that affects bacterial survival and EPS integrity. To test this hypothesis, we developed an in vitro biofilm system using microbiome taken directly from diabetic mouse chronic wounds. For these studies, we chose mice in which chronic wound microbiome was rich in Pseudomonas aeruginosa (97%). We show that NAC at concentrations with pH < pKa causes bacterial cell death and breakdown of EPS. When used before biofilm is formed, NAC leads to bacterial cell death whereas treatment after the biofilm is established NAC causes biofilm dismantling accompanied by bacterial cell death. Mechanistically, we show that NAC can penetrate the bacterial membrane, increase oxidative stress, and halt protein synthesis. We also show that low pH is important for the actions of NAC and that bacterial death occurs independently of the presence of biofilm. In addition, we show that both the acetyl and carboxylic groups play key roles in NAC functions. The results presented here provide insight into the mechanisms by which NAC dismantles biofilm and how it could be used to treat chronic wounds after debridement (NAC applied at the start of culture) or without debridement (NAC applied when biofilm is already formed). This approach can be taken to develop biofilm from microbiome taken directly from human chronic wounds to test molecules that could be effective for the treatment of specific biofilm compositions.

scholarly journals Impact of Bacterial Biofilm Formation on In Vitro and In Vivo Activities of Antibiotics

1998 ◽  
Vol 42 (4) ◽  
pp. 895-898 ◽  
Author(s):  
Silvia Schwank ◽  
Zarko Rajacic ◽  
Werner Zimmerli ◽  
Jürg Blaser
Keyword(s):  
Animal Model ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Phenotypic Resistance ◽  
Vitro Model ◽  
The Impact ◽  
Isogenic Strains

ABSTRACT The impact of bacterial adherence on antibiotic activity was analyzed with two isogenic strains of Staphylococcus epidermidis that differ in the features of their in vitro biofilm formation. The eradication of bacteria adhering to glass beads by amikacin, levofloxacin, rifampin, or teicoplanin was studied in an animal model and in a pharmacokinetically matched in vitro model. The features of S. epidermidis RP62A that allowed it to grow on surfaces in multiple layers promoted phenotypic resistance to antibiotic treatment, whereas strain M7 failed to accumulate, despite initial adherence on surfaces and growth in suspension similar to those for RP62A. Biofilms of S. epidermidis M7 were better eradicated than those of strain RP62A in vitro (46 versus 31%;P < 0.05) as well as in the animal model (39 versus 9%; P < 0.01).

Effect of vancomycin-coated tympanostomy tubes on methicillin-resistant Staphylococcus aureus biofilm formation: in vitro study

2010 ◽  
Vol 124 (6) ◽  
pp. 594-598 ◽  
Author(s):  
C H Jang ◽  
H Park ◽  
Y B Cho ◽  
C H Choi
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Silver Oxide ◽  
In Vitro Study ◽  
Bacterial Biofilm ◽  
Tube Placement ◽  
Tympanostomy Tube ◽  
Methicillin Resistant ◽  
Tympanostomy Tubes

AbstractBackground and objective:Bacterial biofilm formation has been implicated in the high incidence of persistent otorrhoea after tympanostomy tube insertion. It has been suggested that the tube material may be an important factor in the persistence of such otorrhoea. Development of methicillin-resistant Staphylococcus aureus otorrhoea after tympanostomy tube placement is a growing concern. We evaluated the effect of using vancomycin and chitosan coated tympanostomy tubes on the incidence of methicillin-resistant Staphylococcus aureus biofilm formation in vitro.Materials and methods:Three sets each of vancomycin-coated silicone tubes (n = 5), commercial silver oxide coated silicone tubes (n = 5) and uncoated tympanostomy tubes (as controls; n = 5) were compared as regards resistance to methicillin-resistant Staphylococcus aureus biofilm formation after in vitro incubation.Results:Scanning electron microscopy showed that the surfaces of the silver oxide coated tubes supported the formation of thick biofilms with crusts, comparable to the appearance of the uncoated tubes. In contrast, the surface of the vancomycin-coated tympanostomy tubes was virtually devoid of methicillin-resistant Staphylococcus aureus biofilm.Conclusion:Vancomycin-coated tympanostomy tubes resist methicillin-resistant Staphylococcus aureus biofilm formation. Pending further study, such tubes show promise in assisting the control of methicillin-resistant Staphylococcus aureus biofilm formation.

scholarly journals Biofilm Formation Reducing Properties of Manuka Honey and Propolis in Proteus mirabilis Rods Isolated from Chronic Wounds

2020 ◽  
Vol 8 (11) ◽  
pp. 1823
Author(s):  
Joanna Kwiecińska-Piróg ◽  
Jana Przekwas ◽  
Michał Majkut ◽  
Krzysztof Skowron ◽  
Eugenia Gospodarek-Komkowska
Keyword(s):  
Proteus Mirabilis ◽  
Biofilm Formation ◽  
Chronic Wounds ◽  
Chronic Wound ◽  
Ethanol Extract ◽  
Minimal Bactericidal Concentration ◽  
Wound Infections ◽  
Manuka Honey ◽  
The Impact ◽  
Chronic Wound Infections

Chronic wound infections are difficult to manage because of the biofilm formation in the wound environment. New measures for eliminating infections are necessary to increase the chance of wound healing. Apitherapy may be the new solution. The aim of this study was to assess the prevalence of wound infection factors and to examine the impact of Manuka honey and ethanol extract of propolis on biofilm formation of Proteus mirabilis isolated from chronic wound infections. According to the findings, the most frequent factors of infection are Staphylococcus aureus (46.1%), Pseudomonas aeruginosa (35.0%), and Proteus mirabilis (10.6%). Minimal inhibitory concentration and minimal bactericidal concentration values were assigned using the microbroth dilution test according to the Clinical and Laboratory Standards Institute. Biofilm of Proteus mirabilis isolates was formed in 96-well polystyrene plates and treated with Manuka honey (concentrations from 1.88% to 30.0%) and ethanol extract of propolis (1.0% to 40.0%). After 24 h, the biofilm viability was expressed by formazan absorbance (λ = 470 nm). Manuka honey reduced the biofilm viability in all, and ethanol extract of propolis in most, of the concentrations tested. Ethanol extract of propolis at the concentrations of 20.0% and 40.0%, reduced biofilm viability stronger than ethanol itself. With these results comes the conclusion that these substances can reduce biofilm formation.

Sign in / Sign up

Export Citation Format

Share Document