@article{ref1,
title="[Creation of a null mutation in the STX[2] gene of Escherichia coli o[157]: H[7]]",
journal="J. Vet. Res.",
year="2007",
author="R., Firouzi",
volume="61",
number="4",
pages="357-361",
abstract="To construct a specific mutation in E.coli O157:H7. Allelic exchange approach for producing stx[2]-negative mutant. 1-Obtaining PCR product from stx[2] gene.2-Cloning this product to T-vector.3-Inseting a gentamicin resistance cassette.4-Transfering the stx[2] gene with GMR cassette to suicide vector.5-Mating donor [SM10 [+pRE107 - stx[2]: GM] and recipient [Str[R]EC960904].6-Selection of single-cross-overs.7-Counter-selection of double cross-overs. Selecting Gm[R]/Str[R] and Amps colonies.8-Confirmation of mutant by PCR and cytotoxigenicity assay on vero cells. In this study, after mating between the donor [SM10[+pRE107 -Stx[2]: GM] and the recipient cells [Str R-EC960904 wild type], colonies were resistant to gentamycin and streptomycin but sensitive to ampicillin. The result of PCR showed that the mutant was the stx[2] negative strain. However, the mutant strain was unable to lyse the vero cells compare to wild type strain. Hutant strain was produced by a suitable suicide vector<p /><p>Language: fa</p>",
language="fa",
issn="2008-2525",
doi="",
url="http://dx.doi.org/"
}