Laboratorio de Diagnostico y Terapia, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
Laboratorio de Diagnostico y Terapia, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Valdivia, Chile; Center for Aquaculture Research (INCAR), Concepción, Chile.
Microb Pathog. 2023 Jan;174:105932. doi: 10.1016/j.micpath.2022.105932. Epub 2022 Dec 5.
Renibacterium salmoninarum is one of the oldest known fish bacterial pathogens. This Gram-positive bacterium is the causative agent of Bacterial Kidney Disease (BKD), a chronic infection that primarily infects salmonids at low temperatures. Externally, infected fish may show exophthalmos, skin blisters, ulcerations, and hemorrhages at the base of the fins and along the lateral line. Internally, the kidney, heart, spleen, and liver may show signs of inflammation. The best characterized virulence factor of R. salmoninarum is p57, a 57 kDa protein located on the bacterial cell surface and secreted into surrounding fish tissue. The p57 protein in fish is the main mediator in suppressing the immune system, reducing antibody production, and intervening in cytokine activity. In this review, we will discuss aspects such as single nucleotide polymorphisms (SNPs) that modify the DNA sequence, variants in the number of copies of MSA genes, physical-chemical properties of the signal peptides, and the limited iron conditions that can modify p57 expression and increase the virulence of R. salmoninarum.
鲑居肠球菌是已知最早的鱼类细菌性病原体之一。这种革兰氏阳性菌是细菌性肾病（BKD）的病原体，BKD 是一种慢性感染，主要在低温下感染鲑鱼。在外部，受感染的鱼可能会出现眼球突出、皮肤水疱、溃疡和鳍基部及侧线沿线出血。在内部，肾脏、心脏、脾脏和肝脏可能会出现炎症迹象。鲑居肠球菌最具特征性的毒力因子是 p57，这是一种位于细菌细胞表面并分泌到周围鱼组织中的 57 kDa 蛋白。鱼类中的 p57 蛋白是主要的免疫抑制介质，可减少抗体产生并干预细胞因子活性。在这篇综述中，我们将讨论一些方面，如改变 DNA 序列的单核苷酸多态性（SNPs）、MSA 基因拷贝数的变异、信号肽的物理化学性质以及有限的铁条件，这些条件可以改变 p57 的表达并增加鲑居肠球菌的毒力。
