Comparison of galE gene of Campylobacter jejuni strains associated Guillain-Barré syndrome
Objective To investigate the Camtrylobacterjejuni's risk factors which were associated with the development of Guillain-Barre syndrome( GBS), the galE gene of C. jejuni strains were sequenced and the sequencing results were compared with other C. jejuni strains. Methods Selecting three GBS-asso-ciated C.jejuni strains isolated from stools of GBS patients who had been diagnosed as AMAN pattern by clin-ical and electrophysiological test from Hebei province, China. After sequencing galE gene, the results were spliced and assembled into a complete sequence by the terminals overlapped each other. The sequences of galE gene were compared with the corresponding sequences in GenBank to find the mutation and constructed the phylogenetic tree. Results The variation frequency of galE sequences of GBS-associated C. jejuni were higher than that of non-GBS-associated C. jejuni. The phylogenetic analysis demonstrated that each of the three C. jejuni strains was separately genetically closed to three strains which sequences have published in GenBank. The alignment with the related sequence of NCTC11168 shows that there are 4 same mutations in the galE gene of the three C. jejuni strains. The phylogenic tree reflected the regional feature of C. jejuni. Conclusion The probability of sequence variation of galE of GBS-associated C.jejuni is significantly higher than non-GBS-associated C. jejuni strains, the relation between the variation and GBS-pathogenesis remains to be further confirmed. The mutations found in the three C. jejuni strains established the foundation for ex-ploring the biologically characteristic of GBS-associated C. jejuni strains. 
 
Key words: 
Guillain-Barre syndrome;  Campylobacter jejuni;  galE gene;  Sequence analysis