Silva Wanderson M, Dorella Fernanda A, Soares Siomar C, Souza Gustavo H M F, Castro Thiago L P, Seyffert Núbia, Figueiredo Henrique, Miyoshi Anderson, Le Loir Yves, Silva Artur, Azevedo Vasco
Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
INRA, UMR1253 STLO, 35042, Rennes, France.
BMC Microbiol. 2017 Mar 22;17(1):55. doi: 10.1186/s12866-017-0925-6.
Corynebacterium pseudotuberculosis biovar ovis, a facultative intracellular pathogen, is the etiologic agent of caseous lymphadenitis in small ruminants. During the infection process, C. pseudotuberculosis changes its gene expression to resist different types of stresses and to evade the immune system of the host. However, factors contributing to the infectious process of this pathogen are still poorly documented. To better understand the C. pseudotuberculosis infection process and to identify potential factors which could be involved in its virulence, experimental infection was carried out in a murine model using the strain 1002_ovis and followed by a comparative proteomic analysis of the strain before and after passage.
The experimental infection assays revealed that strain 1002_ovis exhibits low virulence potential. However, the strain recovered from the spleen of infected mice and used in a new infection challenge showed a dramatic change in its virulence potential. Label-free proteomic analysis of the culture supernatants of strain 1002_ovis before and after passage in mice revealed that 118 proteins were differentially expressed. The proteome exclusive to the recovered strain contained important virulence factors such as CP40 proteinase and phospholipase D exotoxin, the major virulence factor of C. pseudotuberculosis. Also, the proteome from recovered condition revealed different classes of proteins involved in detoxification processes, pathogenesis and export pathways, indicating the presence of distinct mechanisms that could contribute in the infectious process of this pathogen.
This study shows that C. pseudotuberculosis modifies its proteomic profile in the laboratory versus infection conditions and adapts to the host context during the infection process. The screening proteomic performed us enable identify known virulence factors, as well as potential proteins that could be related to virulence this pathogen. These results enhance our understanding of the factors that might influence in the virulence of C. pseudotuberculosis.
绵羊伪结核棒状杆菌生物变种ovis是一种兼性细胞内病原体，是小反刍动物干酪性淋巴结炎的病原体。在感染过程中，伪结核棒状杆菌会改变其基因表达以抵抗不同类型的应激并逃避宿主的免疫系统。然而，促成这种病原体感染过程的因素仍鲜有记载。为了更好地了解伪结核棒状杆菌的感染过程并确定可能涉及其毒力的潜在因素，使用1002_ovis菌株在小鼠模型中进行了实验性感染，随后对传代前后的菌株进行了比较蛋白质组学分析。
实验性感染试验表明，1002_ovis菌株的毒力潜力较低。然而，从感染小鼠脾脏中回收并用于新的感染挑战的菌株，其毒力潜力发生了显著变化。对1002_ovis菌株在小鼠体内传代前后的培养上清液进行的无标记蛋白质组分析表明，有118种蛋白质差异表达。回收菌株特有的蛋白质组包含重要的毒力因子，如CP40蛋白酶和磷脂酶D外毒素，这是伪结核棒状杆菌的主要毒力因子。此外，回收状态下的蛋白质组揭示了参与解毒过程、发病机制和输出途径的不同类别的蛋白质，表明存在可能促成这种病原体感染过程的独特机制。
本研究表明，伪结核棒状杆菌在实验室条件与感染条件下会改变其蛋白质组谱，并在感染过程中适应宿主环境。我们进行的筛选蛋白质组学能够识别已知的毒力因子以及可能与该病原体毒力相关的潜在蛋白质。这些结果增强了我们对可能影响伪结核棒状杆菌毒力的因素的理解。
