Structure and Replication of the Trachoma Agent in Cell Cultures, as shown by Electron Microscopy

Armstrong, John A.; Valentine, R. C.; Fildes, Celia

doi:10.1099/00221287-30-1-59

Cited by 22 publications

(9 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thin sections of the infected host cells contained many forms apparently fixed in the act of binary fission (5-7, 44, 47, 55-57, 66-68, 77, 78, 100). In addition to these dividing forms, many workers also saw structureless matrices in the cytoplasm of host cells infected with the agents of meningopneumonitis and trachoma in which new agent cells were ap parently being organized by some virus-like reproductive process (7,23,58,77,79,100,115) . However, more recent work (6,56) demonstrated that these matrices were artifacts resulting from the disruption of the fragile large de velopmental forms during fixation and embedding of the infected cell for thin-sectioning.…”

Section: Developmental Cyclementioning

confidence: 97%

The Relation of the Psittacosis Group (Chlamydiae) to Bacteria and Viruses

Moulder¹

1966

Annu. Rev. Microbiol.

115

View full text Add to dashboard Cite

Section: Developmental Cyclementioning

confidence: 97%

The Relation of the Psittacosis Group (Chlamydiae) to Bacteria and Viruses

Moulder¹

1966

Annu. Rev. Microbiol.

115

View full text Add to dashboard Cite

“…2 ,~ elementary bodies when multiplying by binary fission. On the other hand, electron micrographs of thin sections of cells infected with high multiplicities of psittacosis organisms (Tajima, Nomura & Kubota, 1957) and trachoma organisms (Armstrong et al 1963) indicate that an early stage of development is the formation of comparatively large bodies or plaques. In the first 24 hr.…”

Section: Discussionmentioning

confidence: 99%

Cell-wall Constituents of Rickettsiae and Psittacosis-Lymphogranuloma Organisms

Perkins¹,

Allison

1963

Journal of General Microbiology

View full text Add to dashboard Cite

SUMMARYThe taxonomic position of organisms belonging to the rickettsiae and psittacosis-lymphogranuloma groups is controversial. Although, like viruses, all pathogenic forms of these organisms are obligate intracellular parasites, in other respects they resemble bacteria. Since a cell wall, deriving its rigidity from mucopeptide, which contains the amino sugar muramic acid as a key constituent, has so far only been found in bacteria and the closely related blue-green algae, the presence of muramic acid in an organism may be used as a taxonomic criterion. The mucopeptides of bacterial cell walls are also often sensitive to lysozyme, so that dissolution by this enzyme serves as an indication of the presence of mucopeptide. Organisms of the rickettsiae and psittacosis-lymphogranuloma groups have been examined for the presence of muramic acid. Critical chemical tests have shown that this substance is present in organisms of both groups. Cell walls of Rickettsia burnetii were dissolved by lysozyme. In the light of these and other results the taxonomic position of these groups of organisms is discussed.

show abstract

“…D, for the Chlamydia suspension at different teuiperatures was KT calculated from formula D = j for spherical particles in Brownian motion {Einstein, ftTTTja 1906), where « = Boltzmann's constant (1-38 x lO-i"); T = the absolute temperature; II = the viscosity of the suspending fluid (poise) and a = the radius of the particles (cm). The value of a was taken as 0-151 x 10~^ cm, from the electron microscopy measurements of trachoma elementary bodies by Armstrong, Valentine and Fildes (1963), who suggested that tliese Chlamydia elementary bodies were truly spherical structures,…”

Section: Diffusion Constant Of Susperu^ionmentioning

confidence: 99%

CONDITIONS FOR GROWTH OF AN OVINE CHLAMYDIA (BEDSONIA) IN CELL CULTURE

Harrison

1972

Immunol Cell Biol

View full text Add to dashboard Cite

When HEp2 cell cultures were inoculated with an ovine Chlamydia very-few inclusions were fonned when the pH of the nietliiim fell to below pH 7*0. Failure to form inclusions was not due to inactivation of organisms by add conditions during the adsorption period, but was apparently due to events subsequent to adsorption whereby inclusion development under acid conditions was inhibited. Although the ovine ChlamtjcHa was inactivated more rapidly at 37° than at 30°, nevertheless adsorption and penetration of organisms into IIEp2 cultures was more efficient at 37° than at 30". The rate of adsorption of organisms was dependent on volume, and the smaller the volume in which a particular do.se of organism.s was su.spended, the greater the number of inclasions formed. From the theory of Brownian motion it was possible to predict that the rate of adsorption on to surfaces by Chlamydia should be slower than that of viruses, because the size of Chlamydia limits tlieir diffusion. It was possible to calculate that no more than 40!£ of this Chlamydia suspension, in cell culture medium, might adsorb from a depth of 0-1 cm on to a surface in 18 hours at 37°. Under tliese conditions, experimentally, only 24S of the total Chlamydia particles in the suspension resulted in inclusions. Inclusion counts were Iiigher in HEp2 cells than in Vero cells. The inclasion counts in HEp2 cell cultures which had not been treated with DEAE-Dextran were increased by addition of 0-5% (v/v) foetal calf serum or bovine serum, or by 0-6-0-8X (w/v) bovine albumin fraction V to the medium in which the organisms were suspended. The counts decreased with higher concentrations of serum or albumin. In DEAE-Dextran-treated cultures inclusion counts were greatly depressed by the presence of bovine albumin fraction V or serum in the medium (except for a slight ri.st' in count with 0-5 (v/v) serum).

show abstract

Structure and Replication of the Trachoma Agent in Cell Cultures, as shown by Electron Microscopy

Cited by 22 publications

References 27 publications

The Relation of the Psittacosis Group (Chlamydiae) to Bacteria and Viruses

The Relation of the Psittacosis Group (Chlamydiae) to Bacteria and Viruses

Cell-wall Constituents of Rickettsiae and Psittacosis-Lymphogranuloma Organisms

CONDITIONS FOR GROWTH OF AN OVINE CHLAMYDIA (BEDSONIA) IN CELL CULTURE

Contact Info

Product

Resources

About