[Serotyping of "Chlamydia psittaci" by microimmunofluorescence test (author's transl)].

Antisera from inbred mice (C57BL and C3H) improve the specificity of the microimmunofluorescence test. We used this method in the serotyping of 6 strains of Chlamydia psittaci of differing origin. Inspite of relatively marked cross-reactions it was possible to distinguish 3 groups: - the first group consisted of 2 strains of avian origin and the LGV strain 33L, - the second group consisted of 2 strains responsible for enzootic abortion in ewes, - in the third group, only 1 strain was found and this belonged to meningo-pneumonitis group. The results suggests than C. psittaci has a complex antigenic structure than does C. trachomatis.