The development of TRIC organisms in cell cultures during multiple infection

Abstract

SUMMARYThe relationship between multiplicity of infection and the yield of organisms and of polysaccharide was studied in BHK 21 cells infected with TRIC organisms. Although an increase in the multiplicity of infection resulted in an increase in the absolute number of organisms per culture, there was a decrease in relation to the number of infecting organisms. The amount of polysaccharide produced was independent of multiplicity of infection; it was not limited by the concentration of glucose in the medium. Polysaccharide leaked from cells and was slowly broken down in the culture medium.

The Development of a TRIC Agent (Chlamydia trachomatis) and its Associated Polysaccharide in Suspended Cell Cultures

“…the yield from one hundred 250 ml Falcon Plastics flasks). The yield and ratio of infective to total elementary bodies were similar to those from infected monolayer cells (Evans, 1972). Provided that most of the infected cells remained whole the yield of elementary bodies/ ml of culture was greatest about 60 h after infection.…”

“…As in TRIC infections of monolayer cultures (Reeve & Taverne, 1967;Evans, 1972), polysaccharide production in suspended cells accompanied the development of elementary bodies. Although the maximum polysaccharide concentration/culture was reached 50 to 60 h after infection of suspended cells, the average polysaccharide content of inclusions continued to increase for at least 30 h after this (Fig.…”

“…This apparent anomaly resulted from disruption of some inclusions and the subsequent enzymatic degradation of polysaccharide during the incubation. Reeve & Taverne (1967) and Evans (1972) showed that the average polysaccharide content of inclusions in B H K~ I monolayer cells decreased rapidly after attaining its maximum 48 h after infection; the decrease was attributed to leakage from the cells and not to their rupture. In suspended cells the amount of polysaccharide released from disrupted inclusions could account for that found in the medium.…”

Some Properties of the Polysaccharide from Cell Cultures Infected with TRIC Agent (Chlamydia trachomatis)

“…Recent findings suggest that chlamydiae produce an enzyme (or enzymes) that directs polysaccharide synthesis, although the host cell controls the amount of polymer formed in the inclusion (Jenkin & Fan, 1971 ;Evans, 1972).…”

“…The polysaccharide associated with TRIC-infected BHK cells is degraded enzymically by cell homogenates at neutral or slightly acid pH (Evans, 1972;Garrett & Harrison, 1973). To avoid this, cells infected 48 h earlier were therefore harvested by centrifugation at 600 g for 10 min and extracted with 5 % (w/v) trichloroacetic acid (TCA) for I h at o "C; preliminary experiments showed that TCA extracted all the polysaccharide from infected cells.…”