Construction and Pathogenicity of Aeromonas hydrophila AhyR Gene Deletion Strain
CHEN Tingting1, XU Jiale2, XU Yilan1, HE Ying1, LU Bingxia1, ZHOU Yingning1, XU Xinting1, QUAN Chenyu1, ZHAO Shuo1, CHEN Zhongwei1
1. Key Laboratory of China(Guangxi)-ASEAN Cross-border Animal Disease Prevention and Control, Ministry of Agriculture and Rural Affairs, Guangxi Key Laboratory of Veterinary Biotechnology, Guangxi Zhuang Autonomous Region Veterinary Research Institute,Nanning 530001, China; 2. College of Animal Science and Technology, Guangxi University, Nanning 530001, China
Abstract：To investigate the effect of AhyR gene in the pathogenicity and biological properties of Aeromonas hydrophila, the AhyR gene deletion strain ΔAhyR and the complement strain AhyR+ were constructed by homologous recombination and combinatorial transfer methods. The growth characteristics, biofilm formation ability, swimming ability, hemolysis and pathogenicity to crayfish were determined in the AhyR gene deletion strain ΔAhyR and the complement strain AhyR+. The results showed that there were not significantly different growth curves and biofilm formation ability in the deletion strain ΔAhyR and the complement strain AhyR+ from those of the parental strain WT (P>0.05).However, ΔAhyR showed a significant increase in swimming ability and hemolytic ability (P<0.05), enhanced virulence, an approximately 10-fold decrease in LD50, and more severe hepatopancreatic damage to red swamp crayfish Procambarus clarkii. Histologic examination revealed hepatocyte necrosis, dilated lumen of the hepatic tubules, and loss of astrological structures in the red swamp crayfish challenged with ΔAhyR, indicating that AhyR gene deletion enhanced the virulence of A. hydrophila and did not affect the growth performance. The findings provided theoretical basis with the in-depth study of the pathogenic mechanism of AhyR gene in A. hydrophila.
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2025, Vol. 44 
