title: Chlamydia psittaci: growth characteristics and enumeration of serotypes 1 and 2 in cultured cells.
abstract: The growth characteristics of Chlamydia psittaci serotypes 1 and 2 (ovine and bovine origin) were studed in mouse L cells. Formation of inclusions and yield of infectious progeny for serotype 1 were maximal when host cells were treated with cycloheximide and the pH in the cell culture medium was 7.2-7.4. The number of cells that contained inclusions and the infectivity yield for serotype 2 were maximal when the pH was 6.6-7.0. Treatments with diethylaminoethyl dextran and cycloheximide increased inclusion formation in serotype 2 but decreased the yield per infected cell. For both serotypes, centrifugation of the chlamydiae onto monolayers infected 50-1,200 times the number of cells infected with use of stationary adsorption. An enumeration method for L-cell infectious units was developed that gave higher titers than the chicken embryo 50% lethal dose after yolk sac inoculation.
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002498:Centrifugation; D002691:Chlamydophila psittaci / Q000254:growth & development*; D003470:Culture Media; D003513:Cycloheximide / Q000494:pharmacology; D003911:Dextrans / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007739:L Cells / Q000382:microbiology; D051379:Mice; D009956:Psittacosis / Q000175:diagnosis; D012703:Serotyping; D012756:Sheep
chemical_list: D003470:Culture Media; D003911:Dextrans; D003513:Cycloheximide