Title Functional analysis of ascP in Aeromonas veronii TH0426 reveals a key role in the regulation of virulence
Author Yongchao Guan, Meng Zhang, Yingda Wang, Zhongzhuo Liu, Zelin Zhao, Hong Wang, Dingjie An, Aidong Qian, Yuanhuan Kang, Wuwen Sun*, and Xiaofeng Shan*
Address College of Veterinary Medicine, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, P. R. China
Bibliography Journal of Microbiology, 60(12),1153-1161, 2022,
DOI 10.1007/s12275-022-2373-8
Key Words Aeromonas veronii, ascP gene, T3SS, virulence
Abstract Aeromonas veronii is a pathogen which can induce diseases in humans, animals and aquatic organisms, but its pathogenic mechanism and virulence factors are still elusive. In this study, we successfully constructed a mutant strain (ΔascP) by homologous recombination. The results showed that the deletion of the ascP gene significantly down-regulated the expression of associated effector proteins in A. veronii compared to its wild type. The adhesive and invasive abilities of ΔascP to EPC cells were 0.82-fold lower in contrast to the wild strain. The toxicity of ΔascP to cells was decreased by about 2.91-fold (1 h) and 1.74-fold (2 h). Furthermore, the LD50 of the mutant strain of crucian carp was reduced by 19.94-fold, and the virulence was considerably attenuated. In contrast to the wild strain, the ΔascP content in the liver and spleen was considerably lower. The titers of serum cytokines (IL-8, TNF-α, and IL-1β) in crucian carp after the infection of the ΔascP strain were considerably lower in contrast to the wild strain. Hence, the ascP gene is essential for the etiopathogenesis of A. veronii TH0426.