[Induction of experimental pneumocystosis, detection and primary isolation of Pneumocystis carinii].

The described model of experimental pneumocystosis is based on the induction of natural latent infection of P. carinii in Wistar strain laboratory rats. As to pharmacological inducing agents immunosuppresive preparations such as Hydrocortisone sol. inj. (Spofa), Cyclosporin A (Merck) and Dexamethasone (Spofa) were used whereby the latter was effective in up 50%. As to non-pharmacological inducing agents, the authors used in combination with the tested inducers a low protein diet (less than 8% protein in the diet); for suppression of associated bacterial contamination tetracycline was added to drinking water. From the infected lungs by two different methods two types of antigens were prepared 1) PCL antigen (Pneumocystis carinii lavage antigen) isolated by rinsing of the lungs and 2) PCWD antigen (P. carinii whole digest antigen) isolated by digestion of the lungs with collagenase and trypsin. Cysts of P. carinii were detected by staining according to Giemsa (staining of internal structures of nuclear cysts) and by modified staining with toluidine blue O (staining of the cyst wall). For isolation of the antigen and for detection of cysts a combination of the two described methods seems to be best.