IDENTIFICATION OF A MULTIGENE FAMILY CODING FOR THE 90 KDA PROTEINS OF THE OVINE ABORTION SUBTYPE OF CHLAMYDIA-PSITTACI

While attempting to identify genes and their corresponding antigens th at could be used to improve the current methods of diagnosing Chlamydi a psittaci infection which causes enzootic abortion in ewes, two candi date clones were isolated from a lambda gt11 genomic DNA expression li brary of ovine abortion subtype (strain S26/3) C. psittaci. These clon es contained fragments of a gene coding for a group of three chlamydia l proteins of approximately 90 kDa which appeared as major immunogens by immunoblotting experiments, indicating their potential as diagnosti c or possibly protective antigens. Southern blotting of S26/3 genomic DNA using the two clones as probes identified a family of three or fou r genes. These represent the first example of protein gene duplication reported in Chlamydia.