scholarly journals Chelator-Induced Dispersal and Killing of Pseudomonas aeruginosa Cells in a Biofilm

2006 ◽  
Vol 72 (3) ◽  
pp. 2064-2069 ◽  
Author(s):  
Ehud Banin ◽  
Keith M. Brady ◽  
E. Peter Greenberg
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Divalent Cations ◽  
Time Lapse ◽  
Confocal Scanning Laser Microscopy ◽  
Antibiofilm Activity ◽  
Edta Treatment ◽  
Gram Positive Bacteria ◽  
Surface Time ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

ABSTRACT Biofilms consist of groups of bacteria attached to surfaces and encased in a hydrated polymeric matrix. Bacteria in biofilms are more resistant to the immune system and to antibiotics than their free-living planktonic counterparts. Thus, biofilm-related infections are persistent and often show recurrent symptoms. The metal chelator EDTA is known to have activity against biofilms of gram-positive bacteria such as Staphylococcus aureus. EDTA can also kill planktonic cells of Proteobacteria like Pseudomonas aeruginosa. In this study we demonstrate that EDTA is a potent P. aeruginosa biofilm disrupter. In Tris buffer, EDTA treatment of P. aeruginosa biofilms results in 1,000-fold greater killing than treatment with the P. aeruginosa antibiotic gentamicin. Furthermore, a combination of EDTA and gentamicin results in complete killing of biofilm cells. P. aeruginosa biofilms can form structured mushroom-like entities when grown under flow on a glass surface. Time lapse confocal scanning laser microscopy shows that EDTA causes a dispersal of P. aeruginosa cells from biofilms and killing of biofilm cells within the mushroom-like structures. An examination of the influence of several divalent cations on the antibiofilm activity of EDTA indicates that magnesium, calcium, and iron protect P. aeruginosa biofilms against EDTA treatment. Our results are consistent with a mechanism whereby EDTA causes detachment and killing of biofilm cells.

Computer-Assisted Analysis of Multi-Color Confocal Microscopic Datasets: Automated Light Microscopic Discrimination of Synaptic Relationships

1996 ◽  
Vol 54 ◽  
pp. 284-285
Author(s):  
M Wessendorf ◽  
A Beuning ◽  
D Cameron ◽  
J Williams ◽  
C Knox
Keyword(s):  
Nerve Fibers ◽  
Confocal Scanning Laser Microscopy ◽  
Computer Assisted ◽  
Nerve Terminals ◽  
Neuronal Somata ◽  
Scanning Laser Microscopy ◽  
Confocal Scanning ◽  
Entire Cell ◽  
Confocal Scanning Laser ◽  
Assisted Analysis

Multi-color confocal scanning-laser microscopy (CSLM) allows examination of the relationships between neuronal somata and the nerve fibers surrounding them at sub-micron resolution in x,y, and z. Given these properties, it should be possible to use multi-color CSLM to identify relationships that might be synapses and eliminate those that are clearly too distant to be synapses. In previous studies of this type, pairs of images (e.g., red and green images for tissue stained with rhodamine and fluorescein) have been merged and examined for nerve terminals that appose a stained cell (see, for instance, Mason et al.). The above method suffers from two disadvantages, though. First, although it is possible to recognize appositions in which the varicosity abuts the cell in the x or y axes, it is more difficult to recognize them if the apposition is oriented at all in the z-axis—e.g., if the varicosity lies above or below the neuron rather than next to it. Second, using this method to identify potential appositions over an entire cell is time-consuming and tedious.

scholarly journals In Vivo Confocal Scanning Laser Microscopy of Human Skin: Melanin Provides Strong Contrast

1995 ◽  
Vol 104 (6) ◽  
pp. 946-952 ◽  
Author(s):  
Milind Rajadhyaksha ◽  
Melanie Grossman ◽  
Dina Esterowitz ◽  
Robert H. Webb ◽  
R Rox Anderson
Keyword(s):  
Human Skin ◽  
Scanning Laser ◽  
Confocal Scanning Laser Microscopy ◽  
Laser Microscopy ◽  
Scanning Laser Microscopy ◽  
Confocal Scanning ◽  
Confocal Scanning Laser ◽  
Strong Contrast

Immunocytochemical demonstration of a SALMFamide-like neuropeptide in the nervous system of adult and larval stages of the human blood fluke, Schistosoma mansoni

Parasitology ◽  
1995 ◽  
Vol 110 (2) ◽  
pp. 143-153 ◽  
Author(s):  
D. J. A. Brownlee ◽  
I. Fairweather ◽  
C. F. Johnston ◽  
M. C. Thorndyke ◽  
P. J. Skuce
Keyword(s):  
Nervous System ◽  
Schistosoma Mansoni ◽  
Cross Reactivity ◽  
Confocal Scanning Laser Microscopy ◽  
Male Worm ◽  
Male And Female ◽  
Larval Stages ◽  
Confocal Scanning ◽  
Confocal Scanning Laser ◽  
Nerve Cords

SUMMARYThe localization and distribution of SALMFamide immunoreactivity (IR), SI(GFNSALMFamide), in the nervous system of both the adult and larval stages of the trematode Schistosoma mansoni has been determined by an indirect immunofluorescent technique in conjunction with confocal scanning laser microscopy (CSLM). Immunostaining was widespread in the nervous system of adult male and female S. mansoni. In the central nervous system (CNS), IR was evident in nerve cells and fibres in the anterior ganglia, cerebral commissure and dorsal and ventral nerve cords. In the peripheral nervous system (PNS), IR was apparent in nerve plexuses associated with the subtegmental musculature, oral and ventral suckers, the lining of the gynaecophoric canal, and in fine nerve fibres innervating the dorsal tubercles of the male worm. In the reproductive system of male and female worms, Sl-IR was only observed around the ootype/Mehlis' gland complex in the female. Immunostaining was also evident in the nervous system of both miracidium and cercarial larval stages. A post-embedding, IgG-conjugated colloidal gold immunostaining technique was employed to examine the subcellular distribution of SALMFamide-IR in the CNS of S. mansoni. Gold labelling of peptide was localized over dense-cored vesicles within nerve cell bodies and fibres constituting the neuropile of the anterior ganglia, cerebral commissure and nerve cords of the CNS. Antigen pre-absorption studies indicated that the results obtained do suggest S1-like immunostaining and not cross-reactivity with other peptides, in particular FMRFamide.

Development and application of confocal scanning laser microscopy methods for studying the distribution of fat and protein in selected dairy products

2001 ◽  
Vol 68 (3) ◽  
pp. 417-427 ◽  
Author(s):  
MARK A. E. AUTY ◽  
MYRA TWOMEY ◽  
TIMOTHY P. GUINEE ◽  
DANIEL M. MULVIHILL
Keyword(s):  
Fat Distribution ◽  
Scanning Laser ◽  
Confocal Scanning Laser Microscopy ◽  
Mozzarella Cheese ◽  
Major Step ◽  
Milk Chocolate ◽  
Laser Microscopy ◽  
Scanning Laser Microscopy ◽  
Confocal Scanning ◽  
Confocal Scanning Laser

Confocal scanning laser microscopy (CSLM) methods were developed to identify fat and protein in cheeses, milk chocolate and milk powders. Various fluorescent probes were assessed for their ability to label fat or protein in selected food products in situ. Dual labelling of fat and protein was made possible by using mixtures of probes. Selected probes and probe mixtures were then used to study (a) structure development of Mozzarella cheese during manufacture and ripening, and (b) the distribution of fat and protein in milk chocolate made with milk powders containing varying levels of free fat. Microstructural changes in the protein and fat phases of Mozzarella cheese were observed at each major step in processing. Aggregation of renneted micelles occurred during curd formation; this was followed by amalgamation of the para-casein into linear fibres during plasticization. Following storage, the protein phase of the Mozzarella became more continuous; entrapping and isolating fat globules. Chocolate made with a high free-fat spray-dried powder blend showed a homogeneous fat distribution, similar to that of chocolate made with roller-dried milk. Chocolate made with whole milk powder containing 10 g free fat/100 g fat showed a non-homogeneous fat distribution with some fat occluded within milk protein particles. These differences in fat distribution were related to Casson yield value and Casson viscosity of the chocolates.

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