Effect of aroC on biological characteristics and pathogenicity of Edwardsiella tarda
LIU Rui 1, GAO Daqing2, ZHAO Dan1, WANG Hongqiu1, XIE Xiaofang1, #br# QI Lin1, YI Tiantian1, PAN Zhen1, ZHANG Haifang1, DU Hong1
（1. Precision Medicine Center, the Second Affiliated Hospital of Soochow University, Suzhou Jiangsu 215004; 2. School of Medicine, Southeast University, Nanjing Jiangsu 210009, China)
Abstract： Objective： To explore the role of aroC in the pathogenic process of Edwardsiella tarda （Et）. Methods: The ΔaroC and CΔaroC of Et were constructed by homologous recombination of suicide plasmid. The effects of aroC on the biological function of Et were analyzed by biofilm formation, motility test, cell adhesion, zebrafish pathogenicity and bacterial colonization. Results: The deletion of aroC gene did not affect the growth rate of Et. Compared with the wild type and the CΔaroC, the biofilm formation, motility, adhesion and extracellular indole production ability of ΔaroC strain decreased significantly (P<0.05 or <0.01). The results of qRT-PCR showed that the transcriptional levels of flagellum synthesis genes fliA and fliC in ΔaroC decreased significantly (P＜0.01), but there was no significant change in the transcriptional levels of flgK, flgL and fliS genes (P＞0.05). Compared with the wild type, symptoms were significantly reduced and higher survival rate were observed in zebrafish infected with ΔaroC, and the colonization number of ΔaroC in intestine and liver of mice was decreased greatly (P<0.05 or <0.01). Conclusion: The aroC can affect the motility, biofilm formation and adhesion, and then regulate the pathogenicity of Et.
［Key words］aroC gene; Edwardsiella tarda; biological characteristics; pathogenicity
