鸭源致病性大肠杆菌Ⅰ型菌毛pilA基因序列测定及生物信息学分析

据GenBank中人源大肠杆菌pilA基因序列,由Oligo 6.0设计一对引物,以提取的鸭源致病性大肠杆菌基因组为模板,进行PCR扩增,获得了5株鸭源致病性大肠杆菌的pilA基因,序列测定和生物信息学分析表明:鸭源致病性大肠杆菌pilA基因核苷酸序列长度为549 bp,编码182aa,与人源、鸡源及猪源大肠杆菌pilA基因之间核苷酸同源性为87.3%~100.0%,氨基酸同源性为87.5%~100.0%。对不同宿主来源大肠杆菌pilA基因所编码蛋白的二级结构、亲水性、抗原性、抗原表位进行预测分析比较,结果显示Ⅰ型菌毛间具有一定的结构相似性,并存在一定的共同抗原位点;系统进化分析表明,各菌株之间的pilA基因遗传相关性与其宿主来源及血清型之间没有严格的相关性。

Sequencing and Bioinformation Analysis of Type Ⅰ Pili PilA Gene of Pathogenic Escherichia coli Isolated from Ducks

According to the published pilA gene sequence of Escherichia coli from human,by using the software of Oligo 6.0,a pair of primers were designed and synthesized.By using the genomic DNA of pathogenic Escherichia coli isolated from duck as templates for polymerase chain reaction(PCR),and 5 strains of duck pathogenic E.coli pilA gene are gained.The sequence and bioinformatics analysis indicate that,the specific amplicons are 549 bp in length and encode 182 amino acid.By comparison,the homology of Nucleotide and amino acid are 87.3%～100.0% and 87.5%～100.0% respectively between the duck pilA gene and other isolates from chicken,pigs and human.The analysis of secondary structure,hydrophilicity,antigenicity and epitope of typeⅠ pili from different isolates shows that they have some structure similarities between each other and they also have some common antigens.The phylogenetic tree shows that the pilA gene relationship between the genetic correlation of different strains and host isolates is not so close,nor is the serotype.