title: [Construction and characterization of enterohemorrhagic Escherichia coli O157:H7 ppk- deleted strain].
abstract: OBJECTIVE
  To construct enterohemorrhagic Escherichia coli (EHEC) O157: H7 ppk gene deletion strains and study its biological characteristics.
  
  
  METHODS
  The gene fragment of kanamycin resistance was amplified using a pair of homologous arm primers whose 5' and 3' ends were homologous with ppk gene and kanamycin resistance gene, respectively. EHEC O157: H7 EDL933w competent strains were prepared and transformed via electroporation with the amplification products. The ppk gene was replaced by kanamycin resistance gene using pKD46-mediated Red recombination system. The recombinant strain was confirmed by PCR and sequencing, and its morphology, growth ability and adhesion were assessed using Gram staining, OD600 value and Giemsa staining.
  
  
  CONCLUSIONS
  We established a ppk-deleted EHEC O157:H7 EDL933w strain with kanamycin resistance and compared the biological characteristics of the wild-type and mutant strains, which may facilitate further study of the regulatory mechanism of ppk gene.
authors: Biosafety Level-3 Laboratory, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China.E-mail: 1072235962@qq.com.
authors: Peng
authors: P
authors: Han
authors: Qi
authors: Q
authors: Sun
authors: Suhui
authors: S
authors: Zhao
authors: Qiwei
authors: Q
authors: Zhang
authors: Chengsong
authors: C
authors: Wan
mesh_terms: D017931:DNA Primers; D019453:Escherichia coli O157 / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics*; D017353:Gene Deletion; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics*; D016133:Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D029968:Escherichia coli Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); C475691:polyphosphate kinase, E coli