Abstract:

The aim of this study was to study structure and ST type of the cmp gene of C. jejuni from Yaks, pigs and chicken. The complete coding frame of cmp gene from 60 C. jejuni isolates (15 from Yaks, 22 from pigs and 23 from chicken) was cloned and analyzed. Neighbor-joining phylogenetic tree was constructed and ST types were determined according to the ST typing standard reported by literature in which one nucleotide variation in a nucleotide sequence was considered a different ST. The results indicated that there were 13 different sequence length types among 60 cmp genes cloned. A total of 7-10 Loop links, 15-20 antigen epitopic sites were predicted in these sequences. The majority of variable nucleotides and putative amino acid positions concentrated in 6 high variable areas, which located at the Loop links that exposed on the surface of C. jejuni. Forty-six ST types were identified in the 60 cloned sequences, moreover, the two strains (one from Yak and the other one from pig) recombined with the C. coli. There is strong phylogenetic variation within the C. jejuni cmp genes, and it is revealed that ST types of C. jejuni cmp gene are associated with host resources and geographic origin of the isolates.