›› 2017, Vol. 29 ›› Issue (12): 1994-1999.DOI: 10.3969/j.issn.1004-1524.2017.12.06

• Animal Science • Previous Articles     Next Articles

Identification of type Ⅰ fimbriae of Escherichia coli isolated from ducks and genetic characteristics of their FimA and FimH genes

HUANG Shulun1, ZHENG Kaiwen1, HU Yang1, LI Zhangcheng1, CHENG Fangjun1, 2, *, SONG Zhenhui1, 2, ZHOU Zuoyong1, 2, LIU Guolin1, LIN Chunfa1, LIN Yongrun1, ZHANG Tingting1   

  1. 1.College of Animal Science, Southwest University, Chongqing 402460, China;
    2. Veterinary Science Engineering Research Center of Chongqing, Chongqing 402460, China
  • Received:2017-05-15 Online:2017-12-20 Published:2018-01-08

Abstract: To study the generation and molecular characteristics of Escherichia coli typeⅠfimbriae from ducks in parts of Sichuan-Chongqing region, the typeⅠfimbriae 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 in FimH 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.

Key words: Escherichia coli, typeⅠ, fimbriae, amino acid, sequence alignment, antigenic epitope

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