title: [Construction of enterohemorrhagic Escherichia coli O157:H7 strains with espF gene deletion and complementation].
abstract: OBJECTIVE
  To construct enterohemorrhagic Escherichia coli (EHEC) O157:H7 strains with delection espF gene and its nucleotide fragment and with espF gene complementation.
  
  
  METHODS
  A pair of homologous arm primers was designed to amplify the gene fragment of kanamycin resistance, which was transformed into EHEC O157:H7 EDL933w strain via the PKD46 plasmid by electroporation. The replacement of the espF gene by kanamycin resistance gene through the PKD46-mediated red recombination system was confirmed by PCR and sequencing. The entire coding region of espF along with its nucleotide fragment was amplified by PCR and cloned into pBAD33 plasmid, which was transformed into a mutant strain to construct the strain with espF complementation. RT-PCR was used to verify the transcription of espF and its nucleotide fragment in the complemented mutant strain.
  
  
  CONCLUSIONS
  We established EHEC O157:H7 EDL933w strains with espF gene deletion and with espF gene complementation. Both espF and its nucleotide fragment were transcribed in the complemented mutant strain. The two strains provide a basis for further study of the regulatory mechanism of espF.
authors.affiliation: Biosafety Level-3 Laboratory, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Hua
authors.forename: Qi
authors.initials: Q
authors.lastname: Sun
authors.forename: Xiangyu
authors.initials: X
authors.lastname: Wang
authors.forename: Yanli
authors.initials: Y
authors.lastname: DU
authors.forename: Na
authors.initials: N
authors.lastname: Shao
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Chengsong
authors.initials: C
authors.lastname: Wan
mesh_terms: D002352:Carrier Proteins / Q000235:genetics*; D017931:DNA Primers; D019453:Escherichia coli O157 / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics*; D017353:Gene Deletion; D047908:Intracellular Signaling Peptides and Proteins; D010957:Plasmids; D016133:Polymerase Chain Reaction
chemical_list: D002352:Carrier Proteins; D017931:DNA Primers; D029968:Escherichia coli Proteins; C489109:EspFU protein, E coli; D047908:Intracellular Signaling Peptides and Proteins