Physiology and pathogenicity of cpdB deleted mutant of avian pathogenic Escherichia coli

Publication date: Available online 17 November 2016 Source:Research in Veterinary Science Author(s): Huifang Liu, Liping Chen, Wei Si, Chunlai Wang, Fangna Zhu, Guangxing Li, Siguo Liu 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 109 CFU/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...
Source: Research in Veterinary Science - Category: Veterinary Research Source Type: research