Unexpected Transcriptome pompTʹ Contributes to the Increased Pathogenicity of a pompT Mutant of Avian Pathogenic Escherichia coli

Publication date: Available online 16 November 2018Source: Veterinary MicrobiologyAuthor(s): Juanhua Liu, Xiaohui Mu, Xiaobo Wang, Haixia Huan, Qingqing Gao, Juan Chen, Peizhuang Qiao, Luyao Jiang, Song Gao, Xiufan LiuAbstractThe lambda red recombination system makes it suitable for screening virulence gene utility in avian pathogenic Escherichia coli (APEC) on account of its wide applicability, simplicity and high efficiency. In APEC E058 (O2 serogroup), there are two copies of the outer membrane protease (ompT) gene, compT encoding cOmpT that is located on the chromosome and pompT encoding pOmpT that is located on a ColV plasmid. However, the relationship between pathogenesis and pompT expression in APEC E058 has yet to be elucidated. Here, we successfully constructed two pompT gene mutants: E058ΔpompT containing a chloramphenicol (cat) resistance gene and E058ΔpompTʹ without the cat gene. By RT-PCR and sequencing analysis, an unexpected transcriptome pompTʹ was detected in mutant strain E058ΔpompTʹ after deletion of the cat gene induced by the lambda red recombination system. Surprisingly, the pathogenicity of mutant E058ΔpompT was significantly attenuated compared to its parental strain in the chicken infection model and HD11 cell model then the pompT gene was knocked out, while the pathogenicity of the other mutant strain E058ΔpompTʹ had no difference. Furthermore, the presence of unexpected transcriptome ompTʹ influenced the bactericidal activity of SPF chicke...
Source: Veterinary Microbiology - Category: Veterinary Research Source Type: research