| Popis: |
Degenerate PCR primers were designed in silico based on two urease structural genes, namely ureA and ureB, for urease-positive thermophilic Campylobacter (UPTC) organisms. Resultant PCR amplification employing these primers generated an amplicon of approximately 2kb, which was cloned and sequenced, in UPTC organisms (n=12), isolated from various parts of Europe and Japan. Overall, sequence similarities were shown to be 96.7 to 99.9% and following sequence alignment analysis, the approximate 1.96kb regions from the 12 isolates were deduced to consist of parts of ureA (about 570 bps) and ureB (about 1390 bps) which contain an overlapping region between the ureA and ureB gene loci. Although a total of 144 heterogeneous sites of all substitutions were located throughout this region, the substitution ratio was higher in the ureA region (1/〓 10 bases) than in the ureB region (1/〓 15 bases). A resulting dendrogram was constructed, which was based on the nucleotide sequence data of 12 UPTC isolates examined and demonstrated that the UPTC organisms were genetically variable. UPTC organisms formed a major cluster with Helicobacter organisms, separate from the other urease-producing bacteria examined, suggesting a shared ancestry between UPTC organisms and Helicobacter. |
