LuxS modulates motility and secretion of extracellular protease in fish pathogen Vibrio harveyi
LuxS modulates motility and secretion of extracellular protease in fish pathogen Vibrio harveyi
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LuxS 调节鱼类病原体哈维氏弧菌的运动和细胞外蛋白酶的分泌
DOI：
10.1139/cjm-2021-0311
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发表时间：
2022
影响因子：
2.8
通讯作者：
You-Lu Su
中科院分区：
文献类型：
--
作者：
Ya-Qiu Zhang;Yi-Qin Deng;Juan Feng;Jian-Mei Hu;Hao-Xiang Chen;Zhi-Xun Guo;You-Lu Su
哈维氏弧菌可引起多种海洋脊椎动物和无脊椎动物的感染和疾病，对水产养殖业有害。LuxS群体感应系统调节多种病原菌中毒力因子的表达。本研究通过构建luxS基因的框内缺失序列，揭示了LuxS基因在哈维氏弧菌生理和毒力中的作用。统计分析表明，野生型（WT）和luxS突变体之间的生长能力，生物膜形成，抗生素敏感性，腹腔注射的毒力，以及哈维氏弧菌定殖的脾脏和肝脏的珍珠龙胆石斑鱼的能力没有显着差异。然而，luxS的缺失降低了胞外蛋白酶的分泌，同时增加了游泳和群集能力。同时，一个luxS缺失突变体表现出生产过剩的侧鞭毛，和一个完整的luxS补充这一缺陷。由于运动性依赖于鞭毛，因此选择了16个哈维氏弧菌鞭毛生物发生相关基因进行进一步分析。基于定量实时逆转录-PCR（qRT-PCR），与哈维氏弧菌345：pMMB 207（ΔluxS+）菌株相比，这些基因的表达水平在ΔluxS：pMMB 207（ΔluxS+）菌株中显著上调，包括极鞭毛基因flaB、flhA、flhF、flhB、flhF、fliS和flrA以及侧鞭毛基因flgA、flgB、fliE、fliF、lafA、lafK和motY。pMMB 207（WT+）和C-ΔluxS菌株在早期、中期指数生长期和稳定生长期的生长情况。我们的研究结果表明，LuxS起着重要的作用，在控制运动，鞭毛的生物合成，并在哈维氏弧菌胞外蛋白酶分泌。
Vibrio harveyi can cause infections and diseases in a variety of marine vertebrates and invertebrates, which are harmful to the aquaculture industry. The LuxS quorum-sensing system regulates the expression of virulence factors in a wide variety of pathogenic bacteria. In this study, an in-frame deletion of the luxS gene was constructed to reveal the role of LuxS in the physiology and virulence of V. harveyi. Statistical analysis showed no significant differences in the growth ability, biofilm formation, antibiotic susceptibility, virulence by intraperitoneal injection, and ability of V. harveyi to colonize the spleen and liver of the pearl gentian grouper between the wild-type (WT) and luxS mutant. However, deletion of luxS decreased the secretion of extracellular protease, while increasing swimming and swarming abilities. Simultaneously, a luxS-deleted mutant showed overproduction of lateral flagella, and an intact luxS complemented this defect. Since motility is flagella dependent, 16 V. harveyi flagella biogenesis related genes were selected for further analysis. Based on quantitative real-time reverse transcription-PCR (qRT-PCR), the expression levels of these genes, including the polar flagella genes flaB, flhA, flhF, flhB, flhF, fliS, and flrA and the lateral flagella genes flgA, flgB, fliE, fliF, lafA, lafK, and motY, were significantly upregulated in the ΔluxS: pMMB207 (ΔluxS+) strain as compared with the V. harveyi 345: pMMB207 (WT+) and C-ΔluxS strains during the early, mid-exponential, and stationary growth phases. Our results indicate that LuxS plays an important role in controlling motility, flagella biogenesis, and extracellular protease secretion in V. harveyi.