Ultrastructural studies of Chlamydia psittaci 6BC variant strains. I. Ultrastructure of the surface layers of egg-passaged 6BC strain

1973 ◽  
Vol 19 (8) ◽  
pp. 887-894
Author(s):  
Linda Poffenroth ◽  
J. W. Costerton ◽  
Nonna Kordová ◽  
John C. Wilt
Keyword(s):  
Chick Embryo ◽  
Microscopic Examination ◽  
Electron Microscopic Examination ◽  
Chlamydia Psittaci ◽  
Gram Negative Bacteria ◽  
Surface Layers ◽  
Electron Microscopic ◽  
Gram Negative ◽  
Ultrastructural Studies ◽  
First Time

Electron microscopic examination of a semipurified Chlamydia psittaci 6BC strain attenuated in chick embryo yolk sac revealed for the first time two morphologically distinct small elementary bodies which differ both in the ultrastructure of their surface layers and in their buoyant densities in sucrose gradients. Also, the morphology of the surface layers of the larger reticulate forms in cell-free systems is described for the first time. Many points of difference between the surface envelopes and internal structure of chlamydial particles and those of Gram-negative bacteria are discussed.

Fine structure of selected species of the genus Thiobacillus as revealed by chemical fixation and freeze-etching

1974 ◽  
Vol 20 (10) ◽  
pp. 1347-1351 ◽  
Author(s):  
Stanley C. Holt ◽  
J. M. Shively ◽  
J. W. Greenawalt
Keyword(s):  
Inclusion Bodies ◽  
Convex Surface ◽  
Cell Envelope ◽  
Electron Microscopic Examination ◽  
Gram Negative Bacteria ◽  
Chemical Fixation ◽  
Electron Microscopic ◽  
Gram Negative ◽  
Freeze Etching ◽  
Outer Plasma Membrane

An electron-microscopic examination of selected species of the genus Thiobacillus was undertaken using the techniques of chemical fixation and freeze-etching. The architecture of the cells was typical of gram-negative bacteria. The multilayered cell envelope was revealed as a complex of smooth, rough, and particle-studded membranes. The particles which covered the outer plasma membrane (convex surface) appeared to contain a differentiated region which might permit a channeling between the exterior and interior of the cell. Inclusion bodies, including paracrystalline arrays, carboxysomes, and granules were present.

Prediagnostic malakoplakia presenting as a chronic inflammatory mass in the soft tissues of the neck

1992 ◽  
Vol 106 (2) ◽  
pp. 173-177 ◽  
Author(s):  
A. G. Douglas-Jones ◽  
C. Rodd ◽  
E. M. V. James ◽  
R. G. S. Mills
Keyword(s):  
Head And Neck ◽  
Microscopic Examination ◽  
Soft Tissues ◽  
Electron Microscopic Examination ◽  
Pathological Findings ◽  
Electron Microscopic ◽  
Inflammatory Mass ◽  
Biopsy Material ◽  
Gram Negative ◽  
E Coli

AbstractMalakoplakia presenting in the head and neck is very rare. We present a case of an inflammatory mass in the neck, clinically mimicking actinomycosis in a 67-year-old man. Repeated culture of E. coli and histological and electron microscopic examination of biopsy material showed an infiltration of granular macrophages and intracellular gram negative bacilli, but no classical Michaelis-Gutmann bodies. The clinical and pathological findings and criteria for the diagnosis of malakoplakia are discussed.

Electron Microscopic Observations on the Effects of Polymixin B Sulfate to Cell Walls of Chlamydia Organisms

1972 ◽  
Vol 30 ◽  
pp. 326-327
Author(s):  
Akira Matsumoto
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Present Report ◽  
Bactericidal Effect ◽  
Chlamydia Psittaci ◽  
Gram Negative Bacteria ◽  
Electron Microscopic ◽  
Cell Content ◽  
Gram Negative ◽  
Reticulate Body

Cell walls of the both types of bodies, mature elementary body(EB) and developmental reticulate body(RB) of Chlamydia psittaci appear the triple layered membrane in thin section. However, in the preparations shadowcast or stained negatively EB cell wall shows hexagonally arrayed structure composed of subunits, 180A in diameter on the inside surface, whereas RB cell wall does not have this structure. Chemical analysis demonstrated that EB cell wall contained a similar amino acid composition with the cell walls of gram-negative bacteria, such as E.coli. The bactericidal effect of polymixin group against gram-negative bacilli is understood that the drug affects to the cell wall and destroys its osmotic regulation. Electron microscopy on the effects of the drug against the gram-negative bacteria revealed the formation of numerous number of projections on the cell wall surface and leakage of cell content through the projections. The present report is concerned with further studies on the fine structure of EB cell walls based on the observation on their response to polymixin B sulfate.

Phagocytic and chlamydiae-inhibiting activities of stimulated and nonstimulated peritoneal mouse macrophages

1976 ◽  
Vol 22 (8) ◽  
pp. 1169-1180 ◽  
Author(s):  
Nonna Kordová ◽  
John C. Wilt
Keyword(s):  
Microscopic Examination ◽  
Monolayer Culture ◽  
Mononuclear Cells ◽  
Electron Microscopic Examination ◽  
Mononuclear Phagocytes ◽  
Chlamydia Psittaci ◽  
Electron Microscopic ◽  
Mouse Macrophages

Phagocytic and chlamydiacidal properties of nonstimulated and stimulated mouse mononuclear cells for two Chlamydia psittaci 6BC strains were investigated. It was determined that macrophages kept in monolayer culture (i.e. stimulated phagocytes) developed much more efficient chlamydiacidal ability than did cells kept in suspension directly after harvest (i.e. nonstimulated phagocytes). A thousandfold decrease of chlamydial infectivity was observed 60 min after induction of phagocytosis in stimulated macrophages, irrespective of the strain offered. In contrast, the infectivity of both chlamydial strains remained essentially unchanged up to 1 h after phagocytosis by nonstimulated phagocytes. Electron-microscopic examination indicated that chlamydiae were disintegrated within phagolysosomes of stimulated phagocytes within minutes after phagocytosis, although ultrastructurally altered chlamydiae not enclosed in vacuoles were also observed in the cytoplasm of several mononuclear phagocytes at different times after phagocytosis.

Ultrastructural studies of Chlamydia psittaci 6BC in situ in yolk sac explants and L cells: a comparison with gram-negative bacteria

1975 ◽  
Vol 21 (10) ◽  
pp. 1433-1447 ◽  
Author(s):  
J. W. Costerton ◽  
Linda Poffenroth ◽  
J. C. Wilt ◽  
Nonna Kordová
Keyword(s):  
Cellular Level ◽  
Yolk Sac ◽  
Chlamydia Psittaci ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Gram Negative ◽  
Ultrastructural Studies ◽  
L Cells ◽  
Morphological Differences

Chlamydia psittaci (6BC) was grown in yolk sac explants and in L cells and fixed by perfusion in situ to provide undamaged material for comparison with gram-negative bacteria. Reticulate, intermediate, and elementary bodies were all seen to lack a well-defined periplasmic space; intermediate and elementary bodies showed condensations of the nucleoid which differ from common bacterial configurations; and the cytoplasm of highly condensed elementary bodies was much more electron dense than that of the gram-negative bacteria, while retaining its basically particulate nature.These important morphological distinctions are interpreted as reflections of a significantly different cellular level of organization in these two groups of organisms. No important morphological differences were noted in comparisons of the chlamydial particles grown in the two different host systems.

Properties of Isolated Mitochondria of Agaricus Bisporus: Their Relationship to Dormancy and the Germination of Spores

1973 ◽  
Vol 31 ◽  
pp. 458-459
Author(s):  
K. S. McCarty ◽  
R. F. Weave ◽  
L. Kemper ◽  
F. S. Vogel
Keyword(s):  
Mitochondrial Dna ◽  
Ethidium Bromide ◽  
Microscopic Examination ◽  
Agaricus Bisporus ◽  
Osmotic Shock ◽  
Electron Microscopic Examination ◽  
Electron Microscopic ◽  
Isolated Mitochondria ◽  
Dna Strands ◽  
Cytoplasmic Ribosomes

During the prodromal stages of sporulation in the Basidiomycete, Agaricus bisporus, mitochondria accumulate in the basidial cells, zygotes, in the gill tissues prior to entry of these mitochondria, together with two haploid nuclei and cytoplasmic ribosomes, into the exospores. The mitochondria contain prominent loci of DNA [Fig. 1]. A modified Kleinschmidt spread technique1 has been used to evaluate the DNA strands from purified whole mitochondria released by osmotic shock, mitochondrial DNA purified on CsCl gradients [density = 1.698 gms/cc], and DNA purified on ethidium bromide CsCl gradients. The DNA appeared as linear strands up to 25 u in length and circular forms 2.2-5.2 u in circumference. In specimens prepared by osmotic shock, many strands of DNA are apparently attached to membrane fragments [Fig. 2]. When mitochondria were ruptured in hypotonic sucrose and then fixed in glutaraldehyde, the ribosomes were released for electron microscopic examination.

Artifact-free electron microscopic immunocytochemistry on rat brain tissue

1991 ◽  
Vol 49 ◽  
pp. 272-273
Author(s):  
Veronika Burmeister ◽  
N. Ludvig ◽  
P.C. Jobe
Keyword(s):  
Microscopic Examination ◽  
Free Electron ◽  
Electron Microscopic Examination ◽  
Ultrastructural Localization ◽  
Rabbit Serum ◽  
Electron Microscopic ◽  
Electron Microscopic Immunocytochemistry ◽  
Phosphate Buffered Saline ◽  
Rat Brain Tissue ◽  
Immune Rabbit

Electron microscopic immunocytochemistry provides an important tool to determine the ultrastructural distribution of various molecules in both normal and pathologic tissues. However, the specific immunostaining may be obscured by artifactual immunoreaction product, misleading the investigator. Previous observations show that shortening the incubation period with the primary antibody from the generally used 12-24 hours to 1 hour substantially reduces the artifactual immunostaining. We now extend this finding by the demonstration of artifact-free ultrastructural localization of the Ca2/calmodulindependent cyclic nucleotide phosphodiesterase (CaM-dependent PDE) immunoreactivity in brain.Anesthetized rats were perfused transcardially with phosphate-buffered saline followed by a fixative containing paraformaldehyde (4%) and glutaraldehyde (0.25%) in PBS. The brains were removed, and 40μm sections were cut with a vibratome. The sections were processed for immunocytochemistry as described by Ludvig et al. Both non-immune rabbit serum and specific CaM-dependent PDE antibodies were used. In both experiments incubations were at one hour and overnight. The immunostained sections were processed for electron microscopic examination.

scholarly journals The antimicrobial potential of cannabidiol

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mark A. T. Blaskovich ◽  
Angela M. Kavanagh ◽  
Alysha G. Elliott ◽  
Bing Zhang ◽  
Soumya Ramu ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Modern Medicine ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
New Class ◽  
Clostridioides Difficile ◽  
Excellent Activity ◽  
Induce Resistance ◽  
First Time

AbstractAntimicrobial resistance threatens the viability of modern medicine, which is largely dependent on the successful prevention and treatment of bacterial infections. Unfortunately, there are few new therapeutics in the clinical pipeline, particularly for Gram-negative bacteria. We now present a detailed evaluation of the antimicrobial activity of cannabidiol, the main non-psychoactive component of cannabis. We confirm previous reports of Gram-positive activity and expand the breadth of pathogens tested, including highly resistant Staphylococcus aureus, Streptococcus pneumoniae, and Clostridioides difficile. Our results demonstrate that cannabidiol has excellent activity against biofilms, little propensity to induce resistance, and topical in vivo efficacy. Multiple mode-of-action studies point to membrane disruption as cannabidiol’s primary mechanism. More importantly, we now report for the first time that cannabidiol can selectively kill a subset of Gram-negative bacteria that includes the ‘urgent threat’ pathogen Neisseria gonorrhoeae. Structure-activity relationship studies demonstrate the potential to advance cannabidiol analogs as a much-needed new class of antibiotics.

scholarly journals Shadowing the Actions of a Predator: Backlit Fluorescent Microscopy Reveals Synchronous Nonbinary Septation of Predatory Bdellovibrio inside Prey and Exit through Discrete Bdelloplast Pores

2010 ◽  
Vol 192 (24) ◽  
pp. 6329-6335 ◽  
Author(s):  
A. K. Fenton ◽  
M. Kanna ◽  
R. D. Woods ◽  
S.-I. Aizawa ◽  
R. E. Sockett
Keyword(s):  
Cell Division ◽  
Outer Membrane ◽  
Fluorescent Microscopy ◽  
Gram Negative Bacteria ◽  
Bacterial Cell Division ◽  
Prey Cell ◽  
Gram Negative ◽  
A Genome ◽  
Predatory Bacteria ◽  
First Time

ABSTRACT The Bdellovibrio are miniature “living antibiotic” predatory bacteria which invade, reseal, and digest other larger Gram-negative bacteria, including pathogens. Nutrients for the replication of Bdellovibrio bacteria come entirely from the digestion of the single invaded bacterium, now called a bdelloplast, which is bound by the original prey outer membrane. Bdellovibrio bacteria are efficient digesters of prey cells, yielding on average 4 to 6 progeny from digestion of a single prey cell of a genome size similar to that of the Bdellovibrio cell itself. The developmental intrabacterial cycle of Bdellovibrio is largely unknown and has never been visualized “live.” Using the latest motorized xy stage with a very defined z-axis control and engineered periplasmically fluorescent prey allows, for the first time, accurate return and visualization without prey bleaching of developing Bdellovibrio cells using solely the inner resources of a prey cell over several hours. We show that Bdellovibrio bacteria do not follow the familiar pattern of bacterial cell division by binary fission. Instead, they septate synchronously to produce both odd and even numbers of progeny, even when two separate Bdellovibrio cells have invaded and develop within a single prey bacterium, producing two different amounts of progeny. Evolution of this novel septation pattern, allowing odd progeny yields, allows optimal use of the finite prey cell resources to produce maximal replicated, predatory bacteria. When replication is complete, Bdellovibrio cells exit the exhausted prey and are seen leaving via discrete pores rather than by breakdown of the entire outer membrane of the prey.

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