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目的了解吉兰-巴雷综合征(GBS)相关空肠弯曲菌(C.jejuni)waaF基因核酸及氨基酸序列特征,分析其遗传进化关系。方法选取3株致GBS C.jejuni菌株,提取其基因组测序。应用生物信息学软件,以NCTC11168序列为参照进行比对,分析waaF基因碱基及相应氨基酸突变、二级结构变化,计算遗传距离。结果 3株致GBS C.jejuni waaF基因均由960个碱基构成,相同碱基突变位点有5个,1081462位zhanxingT→A,lulei、qiaoyuntaoT→G导致相同氨基酸改变:185位D→E,该位点导致α螺旋结构的改变。3株致GBS C.jejuni waaF基因遗传距离较小。结论 GBS相关C.jejuni菌株waaF基因序列存在相同碱基及氨基酸突变及二级结构变化,这可能与C.jejuni致GBS能力的改变相关。河北地区致GBS的C.jejuni在进化上存在聚类现象。
Objective To understand the nucleic acid and amino acid sequence of C.jejuni waaF gene in Guillain-Barre syndrome (GBS) and to analyze its genetic evolution. Methods Three strains of GBS C. jejuni were selected and their genomes were sequenced. Using bioinformatics software, NCTC11168 sequence as a reference for comparison, analysis of waaF gene base and the corresponding amino acid mutations, secondary structure changes, calculate the genetic distance. Results All three strains of GBS C.jejuni waaF gene consisted of 960 bases with five identical base mutation sites. The zhanxingT → A, lulei and qiaoyuntaoT → G at position 1081462 resulted in the same amino acid change: 185 → D, This site leads to a change in the alpha helical structure. Three strains of GBS C.jejuni waaF caused a smaller genetic distance. Conclusion The mutation of the same base and amino acid in the sequence of waaF in GBS-associated C. jejuni strain and the secondary structure change may be related to the change of GBS-induced GBS competence in C. jejuni. C.jejuni to GBS in Hebei Province has clustering evolutionarily.