Piscirickettsia salmonis is a facultative intracellular bacterium that generates piscirickettsiosis affecting salmonids in Chile. The bacterium has the adaptability to survive in the marine environment under multiple stressful conditions. In this sense, this work focused on the analysis of a gene battery associated with biofilm formation under different culture conditions and on the adaptability of this biofilm to different media. The results indicated that the strains LF-89, IBM-034 and IBM-040 were strong biofilm producers, evidencing adaptability to the media by increasing the amount of biofilm through successive growths. Transcript levels of six genes described in various bacteria and P. salmonis, considered to have metabolic functions, and playing a relevant role in biofilm formation, were analyzed to evaluate bacterial functionality in the biofilm. The genes mazE-mazF, implicated in biofilm and stress, were markedly overexpressed in the biofilm condition in the three strains. For its part, gene gltA, an indicator of metabolic activity and related to virulence inhibition in Salmonella typhimurium, also seems to restrain the pathogenesis process in P. salmonis by inhibiting the expression of the virulence-associated genes liso and tcf. Finally, the expression of the glnA gene suggests the use of glutamine as an essential element for the growth of the biofilm.

中文翻译：

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鲑鱼立克次氏体菌株中与生物膜形成相关的代谢和毒力基因的转录分析

鲑鱼立克次氏体是一种兼性的细胞内细菌，会产生影响智利鲑鱼的猴立克体病。该细菌具有在多种压力条件下在海洋环境中生存的适应能力。从这个意义上讲，这项工作的重点是在不同培养条件下与生物膜形成相关的基因电池的分析，以及该生物膜对不同培养基的适应性。结果表明，菌株LF-89，IBM-034和IBM-040是强大的生物膜生产者，通过连续生长增加生物膜的数量，证明了对培养基的适应性。各种细菌和鲑鱼假单胞菌中描述的六个基因的转录水平被认为具有代谢功能，并在生物膜形成中起着重要作用，进行了分析，以评估生物膜中的细菌功能。涉及生物膜和压力的基因mazE-mazF基因在这三个菌株的生物膜条件下明显过表达。就其本身而言，基因gltA是鼠伤寒沙门氏菌中代谢活性的指标，并且与毒力抑制有关，它似乎也通过抑制毒力相关基因liso和tcf的表达来抑制鲑鱼的致病过程。最后，glnA的表达 该基因提示使用谷氨酰胺作为生物膜生长的必需元素。