scholarly journals Candida albicans enhances meropenem tolerance of Pseudomonas aeruginosa in a dual-species biofilm

2019 ◽  
Vol 75 (4) ◽  
pp. 925-935 ◽  
Author(s):  
Farhana Alam ◽  
Dominic Catlow ◽  
Alessandro Di Maio ◽  
Jessica M A Blair ◽  
Rebecca A Hall
Keyword(s):  
Electron Microscopy ◽  
Cystic Fibrosis ◽  
Scanning Electron Microscopy ◽  
Extracellular Matrix ◽  
Pseudomonas Aeruginosa ◽  
Candida Albicans ◽  
Medical Devices ◽  
Fungal Infections ◽  
Biofilm Structure ◽  
Scanning Electron

Abstract Background Pseudomonas aeruginosa is an opportunistic bacterium that infects the airways of cystic fibrosis patients, surfaces of surgical and burn wounds, and indwelling medical devices. Patients are prone to secondary fungal infections, with Candida albicans being commonly co-isolated with P. aeruginosa. Both P. aeruginosa and C. albicans are able to form extensive biofilms on the surfaces of mucosa and medical devices. Objectives To determine whether the presence of C. albicans enhances antibiotic tolerance of P. aeruginosa in a dual-species biofilm. Methods Single- and dual-species biofilms were established in microtitre plates and the survival of each species was measured following treatment with clinically relevant antibiotics. Scanning electron microscopy and confocal microscopy were used to visualize biofilm structure. Results C. albicans enhances P. aeruginosa biofilm tolerance to meropenem at the clinically relevant concentration of 5 mg/L. This effect is specific to biofilm cultures and is dependent upon C. albicans extracellular matrix polysaccharides, mannan and glucan, with C. albicans cells deficient in glycosylation structures not enhancing P. aeruginosa tolerance to meropenem. Conclusions We propose that fungal mannan and glucan secreted into the extracellular matrix of P. aeruginosa/C. albicans dual-species biofilms play a central role in enhancing P. aeruginosa tolerance to meropenem, which has direct implications for the treatment of coinfected patients.

scholarly journals Vulnerability of Pathogenic Biofilms to Micavibrio aeruginosavorus

2006 ◽  
Vol 73 (2) ◽  
pp. 605-614 ◽  
Author(s):  
Daniel Kadouri ◽  
Nel C. Venzon ◽  
George A. O'Toole
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Burkholderia Cepacia ◽  
Flow Cell ◽  
Gram Negative ◽  
Fold Reduction ◽  
Biofilm Structure ◽  
Pathogenic Biofilms ◽  
Scanning Electron

ABSTRACT The host specificity of the gram-negative exoparasitic predatory bacterium Micavibrio aeruginosavorus was examined. M. aeruginosavorus preyed on Pseudomonas aeruginosa, as previously reported, as well as Burkholderia cepacia, Klebsiella pneumoniae, and numerous clinical isolates of these species. In a static assay, a reduction in biofilm biomass was observed as early as 3 hours after exposure to M. aeruginosavorus, and an ∼100-fold reduction in biofilm cell viability was detected following a 24-h exposure to the predator. We observed that an initial titer of Micavibrio as low as 10 PFU/well or a time of exposure to the predator as short as 30 min was sufficient to reduce a P. aeruginosa biofilm. The ability of Micavibrio to reduce an existing biofilm was confirmed by scanning electron microscopy. In static and flow cell experiments, M. aeruginosavorus was able to modify the overall P. aeruginosa biofilm structure and markedly decreased the viability of P. aeruginosa. The altered biofilm structure was likely caused by an increase in cell-cell interactions brought about by the presence of the predator or active predation. We also conducted a screen to identify genes important for P. aeruginosa-Micavibrio interaction, but no candidates were isolated among the ∼10,000 mutants tested.

Neutrophil Derived Cathepsin G Induces Potentially Thrombogenic Changes in Human Endothelial Cells: a Scanning Electron Microscopy Study in Static and Dynamic Conditions

1994 ◽  
Vol 72 (01) ◽  
pp. 140-145 ◽  
Author(s):  
Valeri Kolpakov ◽  
Maria Cristina D'Adamo ◽  
Lorena Salvatore ◽  
Concetta Amore ◽  
Alexander Mironov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Thrombus Formation ◽  
Cathepsin G ◽  
Arterial Segment ◽  
Dynamic Conditions ◽  
Activated Neutrophils ◽  
Scanning Electron

SummaryActivated neutrophils may promote thrombus formation by releasing proteases which may activate platelets, impair the fibrinolytic balance and injure the endothelial monolayer.We have investigated the morphological correlates of damage induced by activated neutrophils on the vascular wall, in particular the vascular injury induced by released cathepsin G in both static and dynamic conditions.Human umbilical vein endothelial cells were studied both in a cell culture system and in a model of perfused umbilical veins. At scanning electron microscopy, progressive alterations of the cell monolayer resulted in cell contraction, disruption of the intercellular contacts, formation of gaps and cell detachment.Contraction was associated with shape change of the endothelial cells, that appeared star-like, while the underlying extracellular matrix, a potentially thrombogenic surface, was exposed. Comparable cellular response was observed in an “in vivo” model of perfused rat arterial segment. Interestingly, cathepsin G was active at lower concentrations in perfused vessels than in culture systems. Restoration of blood flow in the arterial segment previously damaged by cathepsin G caused adhesion and spreading of platelets on the surface of the exposed extracellular matrix. The subsequent deposition of a fibrin network among adherent platelets, could be at least partially ascribed to the inhibition by cathepsin G of the vascular fibrinolytic potential.This study supports the suggestion that the release of cathepsin G by activated neutrophils, f.i. during inflammation, may contribute to thrombus formation by inducing extensive vascular damage.

Vergleich verschiedener Immun-Dekorationsmethoden für die Rasterelektronenmikroskopie am Beispiel eines Protein-Antigens auf der Oberfläche der Hefe Candida albicans/ A Comparison of Decoration Techniques for the Demonstration of Immunocomplexes by Scanning Electron Microscopy: Labeling of a Protein Antigen on the Surface of the Yeast Candida albicans

1985 ◽  
Vol 40 (7-8) ◽  
pp. 539-550 ◽  
Author(s):  
Margarete Borg
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Candida Albicans ◽  
Protein A ◽  
Peritoneal Macrophages ◽  
Polystyrene Latex ◽  
Target Antigen ◽  
Protein Antigens ◽  
Critical Point Drying ◽  
Scanning Electron

Abstract The labeling of immunocomplexes for scanning electron microscopy (SEM) is a fairly new technique, and the various procedures, that have been proposed, have not yet been compared. Such comparative evaluation was performed with Candida protease as a target antigen. This secretory enzyme of the opportunistic yeast Candida albicans can be localized on the surface of fungal blastopores and mycelia, both after growth in proteinaceous medium and upon infection of murine peritoneal macrophages. The presence of the protease antigen was confirmed by immunofluorescence and by immunoperoxidase-light microscopy. The decoration of protease - anti protease complexes for SEM was attempted with colloids derived from the immunoperoxidase reaction, by the immunogold technique, and by antibodies linked to beads of synthetic polymers (polystyrene, polymethacrylate, polyacrolein). In addition, inactivated Staphylococcus aureus was used, which binds to antibodies through its protein-A. The high resolution by SEM of surface structures was matched only by the colloid based decoration techniques. All conjugates with beads suffered from inconsistent binding, which did not correspond with the distribution of the surface antigen. The comparatively best result with beads was obtained with polystyrene (Latex). Colloid based techniques in addition allow for critical point drying, which cannot be applied to synthetic beads in the usual manner.

scholarly journals POTENSI KULTUR CAMPURAN BAKTERI ENDOFIT SEBAGAI PEMACU PERTUMBUHAN BIBIT TANAMAN KARET

2014 ◽  
Vol 32 (2) ◽  
pp. 129 ◽  
Author(s):  
Umi Hidayati ◽  
Iswandi Anas Chaniago ◽  
Abdul Munif ◽  
Siswanto Siswanto ◽  
Dwi Andreas Santosa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Pseudomonas Aeruginosa ◽  
Bacillus Cereus ◽  
Scanning Electron

Bakteri endofit adalah bakteri yang hidup dalam jaringan tanaman, dapat diisolasi melalui sterilisasi permukaan jaringan tanaman. Isolasi bakteri endofit dari tanaman karet yang berpotensi sebagai pemacu pertumbuhan sangat penting dilakukan. Pembuatan kultur campuran dari bakteri endofit diharapkan meningkatkan potensi dalam memacu pertumbuhan yang dapat meningkatkan kualitas bibit batang bawah tanaman karet. Penelitian ini dilakukan dengan tujuan mendapatkan kultur campuran bakteri endofit sebagai pemacu pertumbuhan bibit tanaman karet. Lima bakteri endofit dari tanaman karet yang berpotensi sebagai pemacu pertumbuhan yaitu Bacillus cereus KPD6, Pseudomonas aeruginosa KPA32, Brachybacterium paraconglomeratum LPD74, bacterium (bakteri tidak dikenal) LPD76, dan Providencia vermicola KPA38, diuji kompatibilitas untuk mendapatkan kultur campuran yang dapat meningkatkan pertumbuhan bibit batang bawah PB 260. Semua bakteri endofit terpilih kompatibel satu dengan yang lain. Aplikasi kultur campuran untuk meningkatkan pertumbuhan bibit batang bawah PB 260 memberikan hasil 2 kultur campuran terbaik. Kultur campuran 1 terdiri 2 spesies bakteri yaitu Brachybacterium paraconglomeratum LPD74 dan Providencia vermicola KPA38.  Kultur campuran 2 terdiri 3 spesies bakteri yaitu  Bacillus cereus KPD6, Pseudomonas aeruginosa KPA32, dan Brachybacterium paraconglomeratum LPD74. Bakteri endofit mampu masuk ke planlet bibit karet microcutting yang dibuktikan dengan Scanning Electron Microscopy. Diterima : 19 Mei 2014; Direvisi : 30 Mei 2014; Disetujui : 21 Juni 2014  How to Cite : Hidayati, U., Chaniago, I. A., Munif, A., Siswanto., & Santosa, D. A. (2014). Potensi kultur campuran bakteri endofit sebagai pemacu pertumbuhan bibit tanaman karet. Jurnal Penelitian Karet, 32(2), 129-138. Retrieved from http://ejournal.puslitkaret.co.id/index.php/jpk/article/view/159

scholarly journals Extracellular matrix in ascending aortic aneurysms and dissections – What we learn from decellularization and scanning electron microscopy

PLoS ONE ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. e0213794 ◽  
Author(s):  
Teresa Mimler ◽  
Clemens Nebert ◽  
Eva Eichmair ◽  
Birgitta Winter ◽  
Thomas Aschacher ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Extracellular Matrix ◽  
Aortic Aneurysms ◽  
Scanning Electron

Biofilm development in down flow anaerobic fluidised bed reactors under transient conditions

2002 ◽  
Vol 46 (1-2) ◽  
pp. 253-256
Author(s):  
F. Tessele ◽  
G. Englert ◽  
L.O. Monteggia
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fluidised Bed ◽  
Initial Adhesion ◽  
Scale Down ◽  
Synthetic Solution ◽  
Biofilm Development ◽  
Fluidised Bed Reactor ◽  
Biofilm Structure ◽  
Scanning Electron

Biofilm development onto polypropylene particles (<4 mm) was studied in a laboratory-scale down flow anaerobic fluidised bed reactor. The reactor was fed with a synthetic solution containing sucrose and nutrients, and operated at 35°C during 65 days at 44% bed expansion rate and 36 h HRT. Scanning electron microscopy (SEM) monitored the biofilm development. Initial adhesion occurred within the first 6 hours and after day 44 biofilm structure was complete. The presence of attached cells morphologically similar to Methanotrix bacilli and Methanosarcina sp. was observed by Scanning Electron Microscopy (SEM). The biofilm and the carrier surface roughness were measured by atomic force microscopy (AFM) and yielded 9.1 and 75 nm respectively. Results also showed good correlation between the SEM characterisation and the conventional anaerobic reactor parameters.

APPLICATION OF SCANNING ELECTRONIC MICROSCOPY FOR THE PURPOSE OF STUDYING CANDIDA ALBICANS BIOFILM ON THE SURFACE OF BASIC PLASTICS OF REMOVABLE ORTHOPEDIC DESIGNS

2019 ◽  
Vol 64 (5) ◽  
pp. 308-313 ◽  
Author(s):  
M. G. Chesnokova ◽  
V. A. Chesnokov ◽  
A. Yu. Mironov
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Candida Albicans ◽  
Electron Microscope ◽  
Biofilm Formation ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
Orthopedic Rehabilitation ◽  
Candida Albicans Biofilms ◽  
Scanning Electron

The most common pathology in the clinic of orthopedic dentistry is the presence of partial adentia in patients, manifested in the form of defects of dentition of various localization and length. Removable orthopedic structures in the oral cavity are a potential place for adhesion and colonization of microorganisms. The aim of the research was to study Candida albicans biofilms on the surface of base plastics of removable orthopedic structures using scanning electron microscopy. 175 cultures of C. albicans were isolated and identified from the oral mucosa of patients at various stages of orthopedic rehabilitation. When studying the surface of samples of plastics of hot and cold type polymerization and Candida biofilms using a JEOL JCM 5700 scanning electron microscope (JEOL, Japan), features of biofilm formation were established. An assessment of the nature of the manifestation of the hemagglutinating activity of clinical strains of Candida fungi in the hemagglutination test with human erythrocytes I (O), II (A) of the human and guinea pig blood groups was carried out. The total number of hemagglutinating strains was 37.14%, with the prevalence of the proportion of manna-resistant (MRHA) cultures - 23.43% of cases. Micrographs of the C. albicans yeast-like biofilm biofilm were obtained on the surface of hot and cold-type plastics in incubation dynamics. Scanning electron microscopy revealed the most pronounced changes in the surface of hot plastics of polymerization compared to cold plastics with long incubation of C. albicans, which characterize the loosening of plastics and the appearance of cracks on the surface, and the cracking of a yeast-like fungus biofilm was noted.

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