Baltes Nina, Buettner Falk F R, Gerlach Gerald-F
Institute for Microbiology, Department of Infectious Diseases, University of Veterinary Medicine Hannover, Foundation, 30173 Hannover, Germany.
Vet Microbiol. 2007 Jul 20;123(1-3):110-21. doi: 10.1016/j.vetmic.2007.03.026. Epub 2007 Mar 30.
Actinobacillus pleuropneumoniae, an important respiratory pathogen in swine, is able to persist in host tissues for extended periods of time. In the study presented here, selective capture of transcribed sequences (SCOTS) analysis was used to identify genes expressed by A. pleuropneumoniae in the chronic stage of the disease (21 days post infection). After isolation and reverse transcription of RNA from infected lungs as well as from culture-grown A. pleuropneumoniae, transcribed A. pleuropneumoniae sequences were captured from infected lung tissue and subjected to a subtractive hybridization procedure of lung-derived against culture-derived A. pleuropneumoniae cDNA. Twenty-nine of the thirty-six genes that were identified as in vivo-expressed are involved in transport or metabolic processes. We identified a surface-associated putative 104 kDa subtilisin-like autotransporter serine protease, designated AasP, which has not been described in A. pleuropneumoniae to date. The gene was shown to be present in all 15 A. pleuropneumoniae serotypes. It is transcribed in porcine lung tissue on days 7 and 21 post infection. Under anaerobic conditions in vitro, its expression depends on the global anaerobic regulator HlyX. To our knowledge, this is the first report of an autotransporter protein being regulated by a global anaerobic regulator.
猪胸膜肺炎放线杆菌是猪重要的呼吸道病原体，能够在宿主组织中长期存活。在本研究中，采用转录序列选择性捕获（SCOTS）分析来鉴定猪胸膜肺炎放线杆菌在疾病慢性期（感染后21天）表达的基因。从感染的肺组织以及培养的猪胸膜肺炎放线杆菌中分离RNA并进行逆转录后，从感染的肺组织中捕获猪胸膜肺炎放线杆菌的转录序列，并对肺源猪胸膜肺炎放线杆菌cDNA与培养源猪胸膜肺炎放线杆菌cDNA进行消减杂交。鉴定出的36个体内表达基因中有29个参与转运或代谢过程。我们鉴定出一种表面相关的假定104 kDa枯草杆菌蛋白酶样自转运丝氨酸蛋白酶，命名为AasP，迄今为止在猪胸膜肺炎放线杆菌中尚未见报道。该基因在所有15种猪胸膜肺炎放线杆菌血清型中均存在。在感染后第7天和第21天在猪肺组织中转录。在体外厌氧条件下，其表达依赖于全局厌氧调节因子HlyX。据我们所知，这是关于自转运蛋白受全局厌氧调节因子调控的首次报道。
