Che Jinyuan, Liu Binghong, Fang Qitong, Hu Shaojie, Wang Lei, Bao Baolong
Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China.
Microorganisms. 2025 Feb 10;13(2):386. doi: 10.3390/microorganisms13020386.
The gene, encoding a lipid A phosphatease, is crucial for lipopolysaccharide (LPS) synthesis in Gram-negative bacteria and plays a critical role in their virulence. This study investigated the role of in , a significant marine pathogen causing gastroenteritis in humans and infections in aquatic animals. We constructed an deletion mutant (Δ) and a complementary strain (CΔ) using homologous recombination. The growth, outer membrane permeability, stress and antibiotic sensitivity, biofilm formation, swarming motility, and virulence of the wild-type (WT), Δ, and CΔ strains were assessed. Additionally, the pathogenicity of Δ was evaluated using shrimp models. The results showed that the gene was successfully deleted and complemented, and its deletion did not impair bacterial growth. However, the Δ strain exhibited an increased outer membrane permeability, reduced resistance to stresses and antibiotics, defective biofilm formation, and a reduced swarming motility. In a co-culture, the Δ strain showed attenuated virulence. In shrimp infected with the Δ strain, the cumulative mortality rate was 22%, significantly lower than the 62% observed in the WT strain. Moreover, the expression levels of immune-related genes in the shrimp hepatopancreas were significantly lower in the Δ group, indicating a significant reduction in infection capability and pathogenicity. These findings indicate that the gene is critical for the virulence of and suggest that is a potential target for therapeutic interventions and vaccine development against infections.
该基因编码一种脂多糖磷酸酶，对革兰氏阴性菌的脂多糖（LPS）合成至关重要，并在其毒力中发挥关键作用。本研究调查了在一种导致人类肠胃炎和水生动物感染的重要海洋病原体中的作用。我们利用同源重组构建了一个缺失突变体（Δ）和一个互补菌株（CΔ）。评估了野生型（WT）、Δ和CΔ菌株的生长、外膜通透性、应激和抗生素敏感性、生物膜形成、群体运动性及毒力。此外，使用虾模型评估了Δ的致病性。结果表明该基因成功缺失并得到互补，其缺失并未损害细菌生长。然而，Δ菌株表现出外膜通透性增加、对应激和抗生素的抗性降低、生物膜形成缺陷以及群体运动性降低。在共培养中，Δ菌株显示出毒力减弱。在感染Δ菌株的虾中，累积死亡率为22%，显著低于野生型菌株观察到的62%。此外，Δ组虾肝胰腺中免疫相关基因的表达水平显著降低，表明感染能力和致病性显著降低。这些发现表明该基因对的毒力至关重要，并表明是针对感染的治疗干预和疫苗开发的潜在靶点。
