Aim: To study the polymorphism of flagellin A genotype and its significance in Helicobacter pylori (H. pylori).
Methods: As the template, genome DNA was purified from six clinical isolates of H. pylori from outpatients, and the corresponding flagellin A fragments were amplified by polymerase chain reaction. All these products were sequenced. These sequences were compared with each other, and analyzed by software of FASTA program.
Results: Specific PCR products were amplified from all of these H. pylori isolates and no length divergence was found among them. Compared with each other, the highest ungapped identity is 99.10%, while the lowest is 94.65%. Using FASTA program, the alignments between query and library sequences derived from different H. pylori strains were higher than 90%.
Conclusion: The nucleotide sequence of flagellin A in H. pylori is highly conservative with incident divergence. This information may be useful for gene diagnosis and further study on flagellar antigen phenotype.