Yang Bintong, Zhang Dongxing, Wu Tonglei, Zhang Zhiqiang, Raza Sayed Haidar Abbas, Schreurs Nicola, Zhang Lei, Yang Guilian, Wang Chunfeng, Qian Aidong, Kang Yuanhuan, Shan Xiaofeng
College of Animal Science and Technology, Jilin Provincial Engineering Research Center of Animal Probiotics, Key Laboratory of Animal Production and Product Quality Safety of Ministry of Education, Jilin Agricultural University, Changchun, China.
College of Animal Science and Technology, Key Laboratory of Preventive Veterinary Medicine, Hebei Normal University of Science and Technology, Changli, China.
J Fish Dis. 2019 Mar;42(3):379-389. doi: 10.1111/jfd.12941. Epub 2019 Jan 7.
Aeromonas veronii is one of the main pathogens causing freshwater fish sepsis and ulcer syndrome. More and more cases have shown that it has become an important zoonotic and aquatic agent. In this study, a A. veronii TH0426 mutant strain (ΔlamB) with an in-frame deletion removed nucleotides 10-1,296 of the lamB gene was firstly constructed to investigate its functions. The results showed that the LD value of the mutant ΔlamB to zebrafish and mice was 13.7-fold and 5.6-fold higher than those of the wild-type strain, respectively. The toxicity of wild-type strain to EPC cells was 2.1-fold and threefold higher than those of ∆lamB when infected for 1 and 2 hr. Furthermore, the ability of biofilm formation and the adhesion and invasion to EPC cells of ∆lamB significantly decreased for 5.6-fold and 1.8-fold separately. In addition, motility detection result indicated that ∆lamB lost the swimming ability. The results of flagellar staining and TEM demonstrated that the flagella of ∆lamB were shed. In general, the deletion of lamB gene caused a significant decrease in the virulence and adhesion of A. veronii TH0426, and it can be known that the lamB gene of A. veronii plays a crucial role in the pathogenesis.
维氏气单胞菌是引起淡水鱼败血症和溃疡综合征的主要病原菌之一。越来越多的病例表明，它已成为一种重要的人畜共患病原体和水生致病因子。在本研究中，首先构建了维氏气单胞菌TH0426突变株（ΔlamB），其lamB基因的第10至1296位核苷酸被框内缺失，以研究其功能。结果表明，突变株ΔlamB对斑马鱼和小鼠的LD值分别比野生型菌株高13.7倍和5.6倍。感染1小时和2小时时，野生型菌株对EPC细胞的毒性分别比ΔlamB高2.1倍和3倍。此外，ΔlamB的生物膜形成能力以及对EPC细胞的黏附和侵袭能力分别显著降低了5.6倍和1.8倍。另外，运动性检测结果表明ΔlamB失去了游动能力。鞭毛染色和透射电镜结果表明，ΔlamB的鞭毛脱落。总体而言，lamB基因的缺失导致维氏气单胞菌TH0426的毒力和黏附力显著降低，可以看出维氏气单胞菌的lamB基因在致病过程中起关键作用。
