Sun Boguang, Zhang Min
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071 China.
College of Marine Science and Engineering, Qingdao Agricultural University, 700 Changcheng Road, Qingdao, 266109 China.
Springerplus. 2016 Jan 28;5:92. doi: 10.1186/s40064-016-1733-4. eCollection 2016.
LuxS/AI-2 quorum sensing is involved in the virulence of many bacterial pathogens, including the fish pathogen Edwardsiella tarda. In a previous study, we identified a small peptide, 5906, which inhibits E. tarda LuxS activity by binding specifically to LuxS in a manner that probably prevents the formation of functional LuxS homodimer. In the present study, using Japanese flounder as the experimental animal, we analyzed the antibacterial effect of 5906 produced by DH5α/p5906 (an Escherichia coli strain that produces 5906) and pID5906 (a mammalian plasmid that functional in flounder constitutively expresses 5906) against different bacterial fish pathogens. We found that fish administered with both DH5α/p5906 and pID5906 exhibited reduced bacterial recovery following E. tarda challenge. We also examined the effect of 5906 on the infection caused by another two fish pathogen, Aeromonas hydrophila and Vibrio harveyi. The results indicated that 5906 produced by DH5α/p5906 inhibited the AI-2 activity of A. hydrophila and V. harveyi, and that fish administered with DH5α/p5906 showed enhanced resistance against challenges with both bacteria. These results suggest that 5906 or its analogues/derivatives may be exploited for the development of broad-spectrum antibacterial agents applied in the prevention and control of fish bacterial diseases.
LuxS/AI-2群体感应参与了包括鱼类病原菌迟缓爱德华氏菌在内的许多细菌病原体的毒力。在先前的一项研究中，我们鉴定出一种小肽5906，它通过以可能阻止功能性LuxS同型二聚体形成的方式特异性结合LuxS来抑制迟缓爱德华氏菌的LuxS活性。在本研究中，我们以牙鲆作为实验动物，分析了由DH5α/p5906（一种产生5906的大肠杆菌菌株）和pID5906（一种在牙鲆中起作用并组成型表达5906的哺乳动物质粒）产生的5906对不同鱼类细菌病原体的抗菌效果。我们发现，用DH5α/p5906和pID5906处理的鱼在迟缓爱德华氏菌攻毒后细菌回收率降低。我们还研究了5906对另外两种鱼类病原体嗜水气单胞菌和哈维氏弧菌引起的感染的影响。结果表明，DH5α/p5906产生的5906抑制了嗜水气单胞菌和哈维氏弧菌的AI-2活性，并且用DH5α/p5906处理的鱼对这两种细菌的攻毒均表现出增强的抗性。这些结果表明，可能可以利用5906或其类似物/衍生物来开发用于预防和控制鱼类细菌疾病的广谱抗菌剂。
