scholarly journals Intragenic Antimicrobial Peptide Hs02 Hampers the Proliferation of Single- and Dual-Species Biofilms of P. aeruginosa and S. aureus: A Promising Agent for Mitigation of Biofilm-Associated Infections

2019 ◽  
Vol 20 (14) ◽  
pp. 3604 ◽  
Author(s):  
Lucinda J. Bessa ◽  
Julia R. Manickchand ◽  
Peter Eaton ◽  
José Roberto S. A. Leite ◽  
Guilherme D. Brand ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Laser Scanning ◽  
Multidrug Resistant ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Bacterial Cells ◽  
Generalized Polarization ◽  
Force Microscopy ◽  
Atomic Force

Pseudomonas aeruginosa and Staphylococcus aureus are two major pathogens involved in a large variety of infections. Their co-occurrence in the same site of infection has been frequently reported and is linked to enhanced virulence and difficulty of treatment. Herein, the antimicrobial and antibiofilm activities of an intragenic antimicrobial peptide (IAP), named Hs02, which was uncovered from the human unconventional myosin 1H protein, were investigated against several P. aeruginosa and S. aureus strains, including multidrug-resistant (MDR) isolates. The antibiofilm activity was evaluated on single- and dual-species biofilms of P. aeruginosa and S. aureus. Moreover, the effect of peptide Hs02 on the membrane fluidity of the strains was assessed through Laurdan generalized polarization (GP). Minimum inhibitory concentration (MIC) values of peptide Hs02 ranged from 2 to 16 μg/mL against all strains and MDR isolates. Though Hs02 was not able to hamper biofilm formation by some strains at sub-MIC values, it clearly affected 24 h preformed biofilms, especially by reducing the viability of the bacterial cells within the single- and dual-species biofilms, as shown by confocal laser scanning microscopy (CLSM) and atomic force microscopy (AFM) images. Laurdan GP values showed that Hs02 induces membrane rigidification in both P. aeruginosa and S. aureus. Peptide Hs02 can potentially be a lead for further improvement as an antibiofilm agent.

scholarly journals Susceptibility of Mature Staphylococcus Biofilms to Chinese Herbal Decoction Sanhuang Jiedu: An In Vitro Study

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shaoe Zhang ◽  
Xiao Wang ◽  
Xiaotao Shi ◽  
Honglue Tan ◽  
Himanshu Garg
Keyword(s):  
Laser Scanning ◽  
Multidrug Resistant ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Antibiofilm Activity ◽  
Dependent Manner ◽  
Chinese Herbal ◽  
Titanium Surfaces

Background. External socking and washing with the Chinese herbal Sanhuang Jiedu decoction (SHJD) can effectively control local limb infections with bone and implant exposure. However, the antibiofilm activities of this decoction in vitro have not yet been investigated. Therefore, the aim of this study was to examine the effects and characteristics of SHJD on the mature biofilms of multidrug-resistant staphylococci on a titanium surface. Methods. Biofilm-forming methicillin-resistant Staphylococcus epidermidis ATCC 35984 and S. aureus ATCC 43330, and non-biofilm-forming S. epidermidis ATCC 12228 were selected as the experimental strains. The mature biofilms were prepared on titanium surfaces. The five experimental groups were based on dilution concentrations (DC) of SHJD: the control group (biofilm incubated with 0.85% NaCl solution), the SHJD (DC:1/8) group (initial SHJD solution was diluted 1/8), the SHJD (DC:1/4) group, the SHJD (DC:1/2) group, and the SHJD (DC:1/1) group (initial SHJD solution). The effects of SHJD on the mature biofilms were observed with the bacterial spread plate method, crystal violet (CV) staining, scanning electron microscopy, and confocal laser scanning microscopy. Results. After culture in tryptic soy broth for 72 h, ATCC 43300 and ATCC 35984 produced mature biofilms and ATCC 12228 did not. The optical density value of ATCC 12228 was 0.11 ± 0.02 , significantly lower than that of ATCC 35984 ( 0.42 ± 0.05 ) or ATCC 43300 ( 0.41 ± 0.03 ) ( P < 0.05 ). The mature biofilms of ATCC 43300 and ATCC 35984 clearly disintegrated when incubated for 12–24 h with SHJD (DC:1/1) or SHJD (DC:1/2), showing only scattered bacterial adhesion. In the SHJD (DC:1/4) group, although many residual bacterial colonies still clustered together, presenting a biofilm structure, it was very looser than that in the SHJD (DC:1/8) group in which the biofilm was similar to that in the control group. For ATCC 12228, only colony adhesion was observed, and the number of colonies decreased as the concentration of SHJD or the culture period increased. The quantitative results for the bacterial spread plate and CV staining showed significant differences between the SHJD groups ( P < 0.05 ). Conclusion. SHJD has antibiofilm activity against multidrug-resistant Staphylococcus strains. It weakens or disrupts already-formed mature biofilms on titanium surfaces in a concentration- and incubation time-dependent manner.

scholarly journals Integrated Confocal and Scanning Probe Microscopy for Biomedical Research

2006 ◽  
Vol 6 ◽  
pp. 1609-1618 ◽  
Author(s):  
B.J. Haupt ◽  
A.E. Pelling ◽  
M.A. Horton
Keyword(s):  
Scanning Probe Microscopy ◽  
Laser Scanning ◽  
Fluorescent Imaging ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Pure Material ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ligand Interactions ◽  
Potential Applications

Atomic force microscopy (AFM) continues to be developed, not only in design, but also in application. The new focus of using AFM is changing from pure material to biomedical studies. More frequently, it is being used in combination with other optical imaging methods, such as confocal laser scanning microscopy (CLSM) and fluorescent imaging, to provide a more comprehensive understanding of biological systems. To date, AFM has been used increasingly as a precise micromanipulator, probing and altering the mechanobiological characteristics of living cells and tissues, in order to examine specific, receptor-ligand interactions, material properties, and cell behavior. In this review, we discuss the development of this new hybrid AFM, current research, and potential applications in diagnosis and the detection of disease.

scholarly journals Novel prosthecate bacteria from the candidate phylum Acetothermia revealed by culture-independent genomics and advanced microscopy

2017 ◽  
Author(s):  
Li-Ping Hao ◽  
Simon Jon McIlroy ◽  
Rasmus Hansen Kirkegaard ◽  
Søren Michael Karst ◽  
Warnakulasuriya Eustace Yrosh Fernando ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Metabolic Reconstruction ◽  
Anaerobic Digesters ◽  
Force Microscopy ◽  
Atomic Force ◽  
Culture Independent ◽  
Ecological Importance ◽  
Globally Distributed

AbstractMembers of the candidate phylum Acetothermia are globally distributed and detected in various habitats. However, little is known about their physiology and ecological importance. In this study, an OTU belonging to Acetothermia was detected at high abundance in two full-scale anaerobic digesters. The first closed genome from this phylum was obtained by differential coverage binning of metagenomes and scaffolding with nanopore data. Genome annotation and metabolic reconstruction suggested an anaerobic chemoheterotrophic lifestyle in which the bacterium obtain energy and carbon via fermentation of peptides, amino acids, and simple sugars to acetate, formate, and hydrogen. The morphology was unusual and composed of a central rod-shaped cell with bipolar prosthecae as revealed by fluorescencein situhybridization combined with confocal laser scanning microscopy, Raman microspectroscopy and atomic force microscopy. We hypothesize that these prosthecae allow for increased nutrient uptake by greatly expanding the cell surface area, providing a competitive advantage under nutrient-limited conditions.

scholarly journals Antibiofilm Activity on Candida albicans and Mechanism of Action on Biomembrane Models of the Antimicrobial Peptide Ctn[15–34]

2020 ◽  
Vol 21 (21) ◽  
pp. 8339
Author(s):  
Francisca Lidiane Linhares de Aguiar ◽  
Nuno C. Santos ◽  
Carolina Sidrim de Paula Cavalcante ◽  
David Andreu ◽  
Gandhi Radis Baptista ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antimicrobial Peptide ◽  
Mechanism Of Action ◽  
Laser Scanning ◽  
Fluorescent Dyes ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antibiofilm Activity ◽  
Membrane Composition ◽  
Fungal Cell

Ctn[15–34], the C-terminal fragment of crotalicidin, an antimicrobial peptide from the South American rattlesnake Crotalus durissus terrificus venom, displays remarkable anti-infective and anti-proliferative activities. Herein, its activity on Candida albicans biofilms and its interaction with the cytoplasmic membrane of the fungal cell and with a biomembrane model in vitro was investigated. A standard C. albicans strain and a fluconazole-resistant clinical isolate were exposed to the peptide at its minimum inhibitory concentration (MIC) (10 µM) and up to 100 × MIC to inhibit biofilm formation and its eradication. A viability test using XTT and fluorescent dyes, confocal laser scanning microscopy, and atomic force microscopy (AFM) were used to observe the antibiofilm effect. To evaluate the importance of membrane composition on Ctn[15–34] activity, C. albicans protoplasts were also tested. Fluorescence assays using di-8-ANEPPS, dynamic light scattering, and zeta potential measurements using liposomes, protoplasts, and C. albicans cells indicated a direct mechanism of action that was dependent on membrane interaction and disruption. Overall, Ctn[15–34] showed to be an effective antifungal peptide, displaying antibiofilm activity and, importantly, interacting with and disrupting fungal plasma membrane.

scholarly journals Исследование влияния колхицина на нативные фибробласты методами атомно-силовой и конфокальной микроскопии

2020 ◽  
Vol 90 (11) ◽  
pp. 1938
Author(s):  
М.М. Халисов ◽  
В.А. Пеннияйнен ◽  
С.А. Подзорова ◽  
К.И. Тимощук ◽  
А.В. Анкудинов ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Laser Scanning ◽  
Young's Modulus ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Cell Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Intracellular Content ◽  
Microscopy Data

Using atomic force and confocal laser scanning microscopy, we studied the effect of colchicine, 1 µg/ml, which is known to cause the depolymerization of tubulin microtubules, on the primary rat fibroblast culture. When analyzing atomic force microscopy data, the sliding type of probe–cell contact was revealed by observing a clear increase of deformation signal at the sample inclined areas. For an unambiguous interpretation of the observed variations in the mechanical characteristics of fibroblasts, it is necessary to prove the sliding of the probe over the cell surface. It was found that some fibroblasts are soft and are characterized by a quite uniform distribution of the apparent Young's modulus over their surface, while others, much harder cells have rigid fibrous structures on the Young's modulus map. Colchicine has been shown to cause significant cell hardening in both groups. Confocal microscopy data show that the observed effect is associated with an increase in the intracellular content of F-actin in fibroblasts.

scholarly journals Overcoming Drug Resistance with Alginate Oligosaccharides Able To Potentiate the Action of Selected Antibiotics

2012 ◽  
Vol 56 (10) ◽  
pp. 5134-5141 ◽  
Author(s):  
Saira Khan ◽  
Anne Tøndervik ◽  
Håvard Sletta ◽  
Geir Klinkenberg ◽  
Charlotte Emanuel ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Health Care Systems ◽  
Multidrug Resistant ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bacterial Cells ◽  
Biofilm Growth ◽  
Content Type ◽  
Inappropriate Use ◽  
Alginate Oligosaccharides

ABSTRACTThe uncontrolled, often inappropriate use of antibiotics has resulted in the increasing prevalence of antibiotic-resistant pathogens, with major cost implications for both United States and European health care systems. We describe the utilization of a low-molecular-weight oligosaccharide nanomedicine (OligoG), based on the biopolymer alginate, which is able to perturb multidrug-resistant (MDR) bacteria by modulating biofilm formation and persistence and reducing resistance to antibiotic treatment, as evident using conventional and robotic MIC screening and microscopic analyses of biofilm structure. OligoG increased (up to 512-fold) the efficacy of conventional antibiotics against important MDR pathogens, includingPseudomonas,Acinetobacter, andBurkholderiaspp., appearing to be effective with several classes of antibiotic (i.e., macrolides, β-lactams, and tetracyclines). Using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), increasing concentrations (2%, 6%, and 10%) of alginate oligomer were shown to have a direct effect on the quality of the biofilms produced and on the health of the cells within that biofilm. Biofilm growth was visibly weakened in the presence of 10% OligoG, as seen by decreased biomass and increased intercellular spaces, with the bacterial cells themselves becoming distorted and uneven due to apparently damaged cell membranes. This report demonstrates the feasibility of reducing the tolerance of wound biofilms to antibiotics with the use of specific alginate preparations.

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