Establishment of rat model for Pneumocystis carinii infection and cloning of the surface glycoprotein A gene of Pneumocystis carinii.

OBJECTIVE

To establish a rat model for Pneumocystis carinii infection and to clone surface glycoprotein A (GpA) gene of Pneumocystis carini.

METHODS

Immunosuppression was induced in 5 rats with an immunosuppresion regimen consisting mainly of dexamethasone in a course of 2 weeks, after which pulmonary homogenates of rats infected with Pneumocystis carinii were fed to the immunosuppressed rats. Immunosuppression was maintained for approximately 4 weeks after the feeding to induce Pneumocystis pneumonia in the rats. GpA gene was subsequently amplified from the rats with pneumonia as confirmed by microscope and PCR detection, and was subcloned into T-vector for the transformation of Escherichia coli JM109 strain.

RESULTS

Pneumocystis carinii was detected by microscope and PCR detection in rats with immunosuppression. The length of PCR product was 319 bp as shown by agarose electrophoresis.

CONCLUSION

The rat model of Pneumocystis carinii infection can be established by immunosuppression with dexamethasone and a single oral administration of the pathogen.