Construction of a Salmonella typhimurium STΔybiH strain and its biological characteristics
(2.College of Medicine, Xinxiang University, Xinxiang, Henan, China 453003)
【Abstract】[Background] Salmonella typhimurium is a major zoonotic pathogen that causes a variety of food-borne diseases. The biological function of ybiH gene in S. typhimurium has not been determined. [Objective] In order to define the pathogenicity contribution of ybiH to S. typhimurium, we constructed and characterized the ybiH deletion and complementation strains of S. typhimurium. [Methods] In this paper, the mutant STΔybiH of S. typhimurium CVCC541 standard strain (ST) was constructed using λ-Red homologous recombination system. At the same time, its complementation strain STΔybiH/pybiH was constructed. We then analyzed the growth characteristics, motility, biochemical properties, and virulence of the strains. [Results] The results showed that the growth of STΔybiH was slightly faster than that of ST and STΔybiH/pybiH, while there was no significant difference in motility or biochemical properties. The deletion of ybiH significantly increased the adhesion and invasion of S. typhimurium to IEC-6 cells and RAW 264.7 cells. The results of qRT-PCR showed that the expression of InvH gene was significantly up-regulated in STΔybiH. The deletion of ybiH increased the invasiveness of S. typhimurium. In addition, the intracellular growth rates of ST and STΔybiH did not differ significantly, indicating that the deletion of ybiH had little effect on the survival of S. typhimurium in RAW 264.7 cells. [Conclusion] The ybiH gene mediates the adhesion and invasiveness of S. typhimurium, which provides a theoretical basis for elucidating the function of ybiH gene.
【Keywords】 Salmonella typhimurium; Mutant strain; ybiH gene; Biological characteristics;
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