摘要
为了解川渝部分地区鸭源大肠埃希菌Ⅰ型菌毛产生情况及分子特征,采用MSHA/MRHA试验、PCR扩增Ⅰ型菌毛基因(FimA、FimH)进行菌毛类型鉴定;通过分析FimA氨基酸序列的亲水性、抗原性、表面可及性来预测抗原位点。MSHA/MRHA试验结果显示,MSHA检测阳性率为44.3%;PCR检测FimA阳性率为63.41%,FimH阳性率为100%。氨基酸序列比对结果显示:FimA氨基酸序列与比对株大肠埃希菌(ECOR61)相比,存在19个差异位点;FimH氨基酸序列与比对株(ECOR45)相比,仅少数菌株出现1~2个氨基酸位点差异,表明该片段高度保守。对FimA氨基酸序列进行抗原位点预测,结果显示,多数菌株抗原表位共同区域分布在84~88、142~146、149~150位氨基酸之间,除上述位点外,部分菌株在101~105、130~134位氨基酸出现抗原表位。
To study the generation and molecular characteristics of Escherichia coli type Ⅰ fimbriae from ducks in parts of Sichuan-Chongqing region,the type Ⅰ fimbriae was identified by MSHA/MRHA test,and their FimA and FimH genes were identified by PCR amplification; The hydrophilicity,antigenicity,and surface probability of FimA amino acid sequences were analyzed by DNAStar to predict antigenic sites. The MSHA/MRHA test results showed that the positive rate of MSHA was 44. 3% . PCR results indicated that the positive rate of FimA and FimH were 63. 41% and 100% ,respectively. Amino acid sequences of FimA and FimH were deduced and contrasted respectively with comparative Escherichia coli strain ECOR61 and ECOR45. Amino acid sequence alignment showed that there were 19 different positions in FimA amino acid sequences. However,there were 1-2 different positions inFimH amino acid sequences,it was believed that FimH amino acid sequences were highly conserved. The antigenic sites of FimA amino acid sequences were predicted. The results indicated that antigenic epitopes of most strains were distributed in 84-88,142-146 and 149-150 amino acids. In addition,some other strains' antigenic epitopes appeared at 101-105 and 130-134 amino acids.
出处
《浙江农业学报》
CSCD
北大核心
2017年第12期1994-1999,共6页
Acta Agriculturae Zhejiangensis
基金
重庆市社会事业与民生保障科技创新专项(CSTC2015SHMSZX80020)
重庆市前沿与应用基础研究(cstc2016jcyA0235)
中央高校基本科研业务费(XDJK2017D083)
关键词
大肠埃希菌
Ⅰ型菌毛
氨基酸
序列比对
抗原表位
Escherichia coli
typeⅠfimbriae
amino acid
sequence alignment
antigenic epitope
