Bello-Ortí Bernardo, Howell Kate J, Tucker Alexander W, Maskell Duncan J, Aragon Virginia
Centre de Recerca en Sanitat Animal (CReSA), Institut de Recerca i Tecnologia Agroalimentàries (IRTA), Campus de la Universitat Autònoma de Barcelona, Bellaterra, 08193, Cerdanyola del Vallès, Spain.
Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
Vet Res. 2015 Sep 23;46(1):102. doi: 10.1186/s13567-015-0225-9.
Haemophilus parasuis is a common inhabitant of the upper respiratory tract of pigs, and the causative agent of Glässer's disease. This disease is characterized by polyserositis and arthritis, produced by the severe inflammation caused by the systemic spread of the bacterium. After an initial colonization of the upper respiratory tract, H. parasuis enters the lung during the early stages of pig infection. In order to study gene expression at this location, we sequenced the ex vivo and in vivo H. parasuis Nagasaki transcriptome in the lung using a metatranscriptomic approach. Comparison of gene expression under these conditions with that found in conventional plate culture showed generally reduced expression of genes associated with anabolic and catabolic pathways, coupled with up-regulation of membrane-related genes involved in carbon acquisition, iron binding and pathogenesis. Some of the up-regulated membrane genes, including ABC transporters, virulence-associated autotransporters (vtaAs) and several hypothetical proteins, were only present in virulent H. parasuis strains, highlighting their significance as markers of disease potential. Finally, the analysis also revealed the presence of numerous antisense transcripts with possible roles in gene regulation. In summary, this data sheds some light on the scarcely studied in vivo transcriptome of H. parasuis, revealing nutritional virulence as an adaptive strategy for host survival, besides induction of classical virulence factors.
副猪嗜血杆菌是猪上呼吸道的常见定植菌，也是格拉泽氏病的病原体。该疾病的特征是多浆膜炎和关节炎，由细菌全身扩散引起的严重炎症所致。在初次定植于上呼吸道后，副猪嗜血杆菌在猪感染的早期阶段进入肺部。为了研究该部位的基因表达，我们采用宏转录组学方法对副猪嗜血杆菌长崎株在肺中的体外和体内转录组进行了测序。将这些条件下的基因表达与传统平板培养中的基因表达进行比较，结果显示，与合成代谢和分解代谢途径相关的基因表达普遍降低，同时参与碳获取、铁结合和致病过程的膜相关基因上调。一些上调的膜基因，包括ABC转运蛋白、毒力相关自转运蛋白（vtaAs）和几种假定蛋白，仅存在于有毒力的副猪嗜血杆菌菌株中，突出了它们作为疾病潜在标志物的重要性。最后，分析还揭示了大量反义转录本的存在，它们可能在基因调控中发挥作用。总之，这些数据为副猪嗜血杆菌鲜为人知的体内转录组提供了一些线索，揭示了营养毒力是宿主生存的一种适应性策略，此外还诱导了经典毒力因子。
