O1和O139群霍乱弧菌超级整合子VchintIA基因的变异

Genetic diversity of VchintIA gene in super integron of O1 and O139 Vibrio cholerae isolates

目的研究不同血清群(型)霍乱弧菌超级整合子整合酶基因(VchintIA)的变异及其与霍乱弧菌分类的关系。方法使用聚合酶链反应(PCR)和序列测定的方法对VchintIA基因进行扩增和序列分析。结果在实验菌株中,O1El Tor和O139群霍乱弧菌产毒株以及毒素共调菌毛(toxin co-regulated pilus,tcp)基因簇阳性的O1群非产毒株的VchintIA序列完全一致,tcp基因簇阴性的O1群非产毒株的VchintIA序列在核苷酸水平上与产毒株不同,但是在氨基酸水平上相同。O139非产毒株的VchintIA序列在核苷酸和氨基酸水平上均与产毒株的VchintIA不同。结论 O1和O139霍乱弧菌超级整合子VchintIA存在核苷酸和氨基酸水平上的变异,O139非产毒株中VchintIA的变异与其整合子内部的结构可能相关。

Objective To understand the diversity of VchintIA gene of O1 and O139 V.cholerae and the relationship between the diversity of VchintIA and different lineages of V.cholerae.Methods Polymerase chain reaction,sequencing and bioinformatics analysis were conducted in this study.Results The VchintIA gene amplification was conducted for all tested strains.The sequences of VchintIA gene were identical in toxigenic O1 El Tor,toxgenic O139 and tcp-gene-cluster positive nontoxigenic O1 El Tor strains.The VchintIA gene in tcp-gene-cluster negative nontoxigenic O1 El Tor strains only showed variation at nucleotide level,however,nontoxigenic O139 strains showed the variation in both nucleotide acid level and amino acid level.Conclusion The diversity of VchintIA at both nucleotide acid le4vel and amino acid level were observed in O1 and O139 V.cholerae strains.This variation in the VchintIA of nontoxigenic O139 strains may play certain role in the structural variation of super integron in these strains.