Involved in the biosynthesis of the siderophore staphyloferrin A. Catalyzes the ATP-dependent condensation of D-ornithine and citrate to form a citryl-D-ornithine intermediate. ATP + citrate + D-ornithine = AMP + diphosphate + H(+) + N(5)-[(S)-citryl]-D-ornithine Siderophore biosynthesis. Belongs to the IucA/IucC family.