The pathogen Vibrio vulnificus has been associated with the majority of clinical cases of septicemia and deaths attributed to shellfish consumption. However, reports on biocontrol agents against this pathogen are scarce. In this study, the strain A5 of Bacillus amyloliquefaciens (A5) was evaluated against V. vulnificus. The sensitivity of V. vulnificus to A5 was first assessed in vitro using selected solid media as well as autoclaved oysters (Crassostrea gigas). Then, the ability of A5 to colonize live oysters was evaluated, and the biocontrol efficacy was investigated in vivo using oysters inoculated with V. vulnificus before or after inoculation with A5. The survival of the pathogen in oysters was evaluated after 2, 3, 4, and 6 days of exposure to A5 in all the experiments. In vitro, A5 showed inhibition halos of 18 mm against V. vulnificus. In autoclaved oysters, A5 caused a significant reduction in the levels of V. vulnificus on day 2 at 5.14 log CFU/g, but the pathogen’s counts were restored after day 3. In vivo, A5 was able to survive in live oysters and prevented the colonization of V. vulnificus only when the biocontrol agent was inoculated before the pathogen. Results show the potential of A5 to prevent V. vulnificus uptake by oysters when administered prior to the pathogen.

中文翻译：

---

一株解淀粉芽孢杆菌可以防止巨牡蛎中创伤弧菌的定植

病原体创伤弧菌与大多数因食用贝类导致的败血症和死亡临床病例有关。然而，关于针对这种病原体的生物防治剂的报道很少。在这项研究中，解淀粉芽孢杆菌 (A5) 的 A5 菌株针对创伤弧菌进行了评估。V. vulnificus 对 A5 的敏感性首先在体外使用选定的固体培养基以及高压灭菌的牡蛎（Crassostrea gigas）进行评估。然后，评估了 A5 定殖活牡蛎的能力，并在接种 A5 之前或之后使用接种了创伤弧菌的牡蛎在体内研究了生防效果。在所有实验中，在暴露于 A5 2、3、4 和 6 天后评估牡蛎中病原体的存活率。在体外，A5 对创伤弧菌显示出 18 毫米的抑制光晕。在高压灭菌的牡蛎中，A5 在第 2 天以 5.14 log CFU/g 显着降低创伤弧菌的水平，但病原体的数量在第 3 天后恢复。在体内，A5 能够在活牡蛎中存活并防止只有在病原体之前接种生物防治剂时，创伤弧菌才能定植。结果表明，在病原体感染之前施用 A5 时，A5 有可能阻止牡蛎摄取创伤弧菌。