文献类型： 外文期刊

作者： Zhang, Y. ¹ ; Deng, Y. ¹ ; Feng, J. ¹ ; Hu, J. ¹ ; Chen, H. ¹ ; Guo, Z. ¹ ; Gao, R. ³ ; Su, Y. ¹ ;

作者机构： 1.Chinese Acad Fishery Sci, South China Sea Fisheries Res Inst, Key Lab South China Sea Fishery Resources Exploit, Minist Agr & Rural Affairs, Guangzhou, Peoples R China

2.Shanghai Ocean Univ, Coll Fisheries & Life Sci, Shanghai, Peoples R China

3.Zhaoqing Dahuanong Biol Med Co Ltd, Zhaoqing, Guangdong, Peoples R China

4.Zhongkai Univ Agr & Engn, Coll Anim Sci & Technol, Innovat Inst Anim Hlth Breeding, Guangzhou, Peoples R China

关键词： biofilm formation; gene knockout; phenotypic characterization; toxR; Vibrio harveyi

期刊名称：LETTERS IN APPLIED MICROBIOLOGY （ 影响因子：2.813； 五年影响因子：3.086 ）

ISSN： 0266-8254

年卷期： 2022 年 74 卷 2 期

页码：

收录情况： SCI

摘要： Vibrio harveyi is a common aquaculture pathogen causing diseases in a variety of aquatic animals. toxR, a conserved virulence-associated gene in vibrios, is identified in V. harveyi 345, a pathogenic strain isolated from diseased fish. In this study, to gain insight into function of ToxR in V. harveyi, an in-frame deletion of the toxR gene was constructed to reveal the role of ToxR in the physiology and virulence of V. harveyi. The statistical analysis showed no significant differences in the growth ability, motility, extracellular protease secretion, antibiotic susceptibility, virulence by intraperitoneal injection and the ability of V. harveyi to colonize the spleen and liver tissues of the pearl gentian grouper between the wild-type (WT) and the toxR mutant. However, the deletion of toxR increased the biofilm formation. The structure of the V. harveyi biofilm was further analysed by using scanning electron microscopy (SEM) and confocal laser scanning microscopy, and the results showed that deletion of toxR increased the number and density of V. harveyi biofilm. Since biofilm production is flagella, exopolysaccharide (EPS) and lipopolysaccharide dependent, 16 of V. harveyi biofilm-related genes were selected for further analysis. Based on quantitative real-time reverse transcription-PCR, the expression levels of these genes, including genes flrB, motY and mshA, flaE, flrA and gmhD, were significantly up-regulated in the Delta toxR(+) strain as compared with the WT+ and C-Delta toxR strains during the early and mid-exponential, while epsG, flaA, flaE, flgD, flgE, flrB, flrC, lpxB, motY, mshA and scrG genes were inhibited because of deletion of the toxR gene in the stationary growth phase. Our results indicate that ToxR plays an important role in controlling the biofilm in V. harveyi.