Isolation of a restriction-less mutant and development of a shuttle vector for the genetic analysis of Campylobacter hyointestinalis.

A cosmid shuttle cloning vector, pCHI15, was constructed which could be mobilized from Escherichia coli K-12 to a putative restriction-less mutant of Campylobacter hyointestinalis, C. fetus subsp. fetus, and C. fetus subsp. venerealis at a frequency of 10(-4) transconjugants per donor. A previously described C. coli shuttle vector, pILL550, could not be mobilized into the C. hyointestinalis restriction-less mutant, implying that the C. coli replicon was not functional in a C. hyointestinalis host. The type strains of C. jejuni, C. coli, C. fetus subsp. fetus, and C. hyointestinalis were analysed for their ability to be transformed by plasmid DNA which had been modified by other Campylobacter species. Each Campylobacter species was found to be most efficiently transformed by plasmid DNA that had been previously passaged in the same species. pCHI15 could be mobilized from C. coli into C. fetus subsp. fetus and the putative restriction-less mutant of C. hyointestinalis at a frequency of 3.0 x 10(-4) and 2.5 x 10(-3) transconjugants per donor, respectively.