Differentiation between Campylabacter hyoilei and Campylobacter coli usinggenotypic and phenotypic analyses

Genotypic and phenotypic methods were applied to investigate differences be tween the closely related species Campylobacter hyoilei and Campylobacter c oli. A unique DNA sequence from C. hyoilei was used to design a specific PC R assay that amplified a DNA product of 383 bp for all C. hyoilei strains, but not other Campylobacter species, including C. coli, The PCR assay could detect 100 fg pure C. hyoilei DNA, 2 x 10(2) c.f.u, ml(-1) using cultured cells and 8.3 x 10(3) c.f.u. 0.1 g(-1) in faeces, The C. hyoilei sequence u tilized for specific detection and identification of this species showed si milarities to sequences from bacteriophages Mu, P2 and 186, suggesting lyso gination of the ancestral C, hyoilei genome. Activities of a set of 15 enzy mes that participate in a variety of cellular functions, including biosynth esis, catabolism, energy generation, maintenance of redox balance and phosp hate utilization, were tested using sets of strains of C. hyoilei and C. co li. Comparison of mean rates of enzyme activities revealed significant diff erences between species in the values determined for seven of these activit ies. Both the genetic and phenotypic data indicate that C. hyoilei is a uni que Campylobacter species.