title: Physiology and pathogenicity of cpdB deleted mutant of avian pathogenic Escherichia coli.
abstract: Avian colibacillosis is one of the most common infectious diseases caused partially or entirely by avian pathogenic Escherichia coli (APEC) in birds. In addition to spontaneous infection, APEC can also cause secondary infections that result in greater severity of illness and greater losses to the poultry industry. In order to assess the role of 2', 3'-cyclic phosphodiesterase (cpdB) in APEC on disease physiology and pathogenicity, an avian pathogenic Escherichia coli-34 (APEC-34) cpdB mutant was obtained using the Red system. The cpdB mutant grew at a slower rate than the natural strain APEC-34. Scanning electron microscopy (SEM) indicated that the bacteria of the cpdB mutant were significantly longer than the bacteria observed in the natural strain (P<0.01), and that the width of the cpdB mutant was significantly smaller than its natural counterpart (P<0.01). In order to evaluate the role of cpdB in APEC in the colonization of internal organs (lung, liver and spleen) in poultry, seven-day-old SPF chicks were infected with 109CFU/chick of the cpdB mutant or the natural strain. No colonizations of cpdB mutants were observed in the internal organs 10days following the infection, though numerous natural strains were observed at 20days following infection. Additionally, the relative expression of division protein ftsZ, outer membrane protein A ompA, ferric uptake regulator fur and tryptophanase tnaA genes in the mutant strain were all significantly lower than in the natural strain (P<0.05 or P<0.01). These results suggested that cpdB is involved in the long-term colonization of APEC in the internal organs of the test subjects. The deletion of the cpdB gene also significantly affected the APEC growth and morphology.
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Disease of Harbin Veterinary Research Institute, Chinese Academy of Agricultural Science, Harbin, China; Tianjin Key Laboratory of Molecular Drug Research, Tianjin International Joint Academy of Biomedicine, Tianjin, China; Northeast Agricultural University, Harbin, China.
authors.forename: Huifang
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Disease of Harbin Veterinary Research Institute, Chinese Academy of Agricultural Science, Harbin, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Disease of Harbin Veterinary Research Institute, Chinese Academy of Agricultural Science, Harbin, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Si
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Disease of Harbin Veterinary Research Institute, Chinese Academy of Agricultural Science, Harbin, China.
authors.forename: Chunlai
authors.initials: C
authors.lastname: Wang
authors.affiliation: Tianjin Key Laboratory of Molecular Drug Research, Tianjin International Joint Academy of Biomedicine, Tianjin, China.
authors.forename: Fangna
authors.initials: F
authors.lastname: Zhu
authors.affiliation: Northeast Agricultural University, Harbin, China. Electronic address: ligx@neau.edu.cn.
authors.forename: Guangxing
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Disease of Harbin Veterinary Research Institute, Chinese Academy of Agricultural Science, Harbin, China. Electronic address: siguo_liu@hvri.ac.cn.
authors.forename: Siguo
authors.initials: S
authors.lastname: Liu
mesh_terms: D000818:Animals; D002645:Chickens / Q000382:microbiology*; D004926:Escherichia coli / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D009708:Nucleotidases / Q000235:genetics / Q000378:metabolism*; D011201:Poultry Diseases / Q000382:microbiology*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics
chemical_list: D029968:Escherichia coli Proteins; D037521:Virulence Factors; D009708:Nucleotidases; C040470:3'-nucleotidase
keywords: Avian pathogenic Escherichia coli (APEC); Deletion; Pathogenicity; Physiology; cpdB gene