Comparison of Partial 16S rRNA Sequences of Different Helicobacter pylori Strains, Helicobacter mustelae and a Gastric Campylobacter-like Organism (GCLO)

Partial 16S rRNA sequences of seven Helicobacter pylori strains from three different continents were compared. High homogeneity (99.5%–100%) of 16S rRNA between H. pylori strains was demonstrated, when a 397 nucleotides long stretch of RNA was compared. The obtained consensus sequence was practically identical with one of the two published sequences, 99.4% similarity ( Romaniuk et al., J. Bact. 169, 2137–2141 (1987)), whereas with the other published sequence the identity was lower, 95.8% similarity ( Thompson et al., Int. J. System. Bact. 38, 190–200 (1988)). Comparison of the consensus H. pylori sequence with the sequence of Helicobacter mustelae, the spiral organism isolated from ferrets, revealed 93.8% similarity. H. mustelae was also compared with published sequences of Wollinella succinogenes, and Campylobacter jejuni. The percentual sequence similarities were 96.0 and 83.7, respectively. A gastric campylobacter-like organism (GCLO, NCTC 11847), isolated from the gastric antrum has been demonstrated to resemble C. jejuni biochemically. By 16S rRNA sequences we demonstrate that the GCLO is in fact a C. jejuni strain.