ABSTRACT
DNA fragments coding for the ribosomal RNA and the surface array proteins of Campylobacter fetus have been cloned from a genomic library constructed in Escherichia coli. They were used in the molecular characterization of C. fetus (subsp. fetus; subsp. venerealis) strains by restriction fragment length polymorphism (RFLP) method. Ribotyping results showed that all strains of the two subspecies can be classified under one ribogroup implying very close relatedness. The sapA gene DNA marker, however, discriminated all the strains regardless of the subspecies when chromosomal DNA was restricted with HindIII, HaeIII, XbaI or EcoRV. These results illustrate that the sapA probe is potentially useful in fingerprinting C. fetus strains and in determining the relationships of strains for epidemiological purposes.