Laboratory of Aquatic Pathobiology, Environmental and Marine Biology, Department of Biosciences, Åbo Akademi University, Turku/Åbo, Finland.
J Fish Dis. 2011 Apr;34(4):255-64. doi: 10.1111/j.1365-2761.2010.01232.x. Epub 2011 Feb 7.
A Pseudomonas sp. isolate MSB1 efficiently inhibited the growth of Flavobacterium psychrophilum of different serotypes on agar medium. A significant difference in the inhibition was observed between isolates of the less virulent Fp(T) serotype compared to the Fd and Th serotypes. In broth coculture experiments, a low number of cells of MSB1 inhibited and outcompeted the F. psychrophilum cells. Also cell-free culture supernatant of MSB1 clearly repressed the growth of F. psychrophilum. A chromoazurol S assay suggested that MSB1 produced efficient siderophores, which most probably were responsible for the iron deficiency in the supernatant. The limited growth of F. psychrophilum in the supernatant was found to be partly because of the lack of available iron, but the results also indicated that some other mechanisms were probably involved in the observed inhibition. A potential use of MSB1 as a probiotic in rainbow trout aquaculture, especially in early life stages of the fish, is suggested, but future in vivo experiments needs to be carried out to verify this suggestion. This study also indicates a low iron acquisition efficiency of F. psychrophilum, compared to other examined bacterial fish pathogens.
一株假单胞菌 MSB1 能有效抑制不同血清型嗜冷性杀鲑气单胞菌在琼脂培养基上的生长。与 Fd 和 Th 血清型相比，低毒力 Fp(T)血清型的分离株之间观察到的抑制差异显著。在液体共培养实验中，MSB1 的少量细胞能抑制并竞争嗜冷性杀鲑气单胞菌细胞。此外，MSB1 的无细胞培养上清液也能明显抑制嗜冷性杀鲑气单胞菌的生长。铬天青 S 测定表明，MSB1 产生了高效的铁载体，这很可能是导致上清液中铁缺乏的原因。嗜冷性杀鲑气单胞菌在上清液中生长受限，部分原因是铁供应不足，但结果也表明，观察到的抑制可能涉及其他一些机制。建议将 MSB1 作为一种益生菌用于虹鳟鱼养殖，特别是在鱼类的早期生活阶段，但需要进行未来的体内实验来验证这一建议。本研究还表明，与其他检查过的鱼类病原菌相比，嗜冷性杀鲑气单胞菌对铁的获取效率较低。
