Jeannotte Marie-Eve, Abul-Milh Maan, Dubreuil J Daniel, Jacques Mario
Groupe de Recherche sur les Maladies Infectieuses du Porc, Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, St. Hyacinthe, Québec, Canada J2S 7C6.
Infect Immun. 2003 Aug;71(8):4657-63. doi: 10.1128/IAI.71.8.4657-4663.2003.
The gram-negative bacterium Actinobacillus pleuropneumoniae is the causative agent of porcine fibrinohemorrhagic necrotizing pleuropneumonia, a disease that causes important economic losses to the swine industry worldwide. In general, the initial step of bacterial colonization is attachment to host cells. The purpose of the present study was to evaluate the binding of A. pleuropneumoniae serotype 1 to phospholipids, which are the major constituents of biological membranes. Phospholipids serve as receptors for several bacteria, including respiratory pathogens. To study this effect, we used thin-layer chromatography overlay binding assays to test commercial phospholipids such as phosphatidic acid, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, and phosphatidylethanolamine (PE). Our results indicate that A. pleuropneumoniae serotype 1 binds to PE but not to the other phospholipids tested. Serotypes 5b and 7, which, along with serotype 1, are the most prevalent serotypes of A. pleuropneumoniae in North America, share the ability to bind PE. Inhibition of binding with a monoclonal antibody against A. pleuropneumoniae serotype 1 O antigen and the use of isogenic lipopolysaccharide (LPS) mutants of A. pleuropneumoniae serotype 1 showed that the O antigen seems to be implicated in the binding to PE, at least for A. pleuropneumoniae serotype 1. A. pleuropneumoniae was also shown to bind to a phospholipid extracted from swine lungs by using the method of Folch. Chemical staining with molybdenum blue and ninhydrin, migration with neutral, acidic, and basic solvent systems, and mass spectrometry analysis all indicated that this lipid is PE. This study is, to the best of our knowledge, the first description of A. pleuropneumoniae binding to phospholipids. Our data also suggest that LPS O antigens could be involved in binding to PE.
革兰氏阴性菌胸膜肺炎放线杆菌是猪纤维蛋白出血性坏死性胸膜肺炎的病原体，这种疾病给全球养猪业造成了重大经济损失。一般来说，细菌定植的第一步是附着于宿主细胞。本研究的目的是评估1型胸膜肺炎放线杆菌与磷脂（生物膜的主要成分）的结合情况。磷脂可作为包括呼吸道病原体在内的多种细菌的受体。为研究这种作用，我们使用薄层色谱覆盖结合试验来检测商业磷脂，如磷脂酸、磷脂酰胆碱、磷脂酰丝氨酸、磷脂酰肌醇、磷脂酰甘油和磷脂酰乙醇胺（PE）。我们的结果表明，1型胸膜肺炎放线杆菌与PE结合，但不与其他测试的磷脂结合。5b型和7型血清型，与1型血清型一样，是北美胸膜肺炎放线杆菌最常见的血清型，它们都具有结合PE的能力。用抗1型胸膜肺炎放线杆菌O抗原的单克隆抗体抑制结合以及使用1型胸膜肺炎放线杆菌的同基因脂多糖（LPS）突变体表明，O抗原似乎与PE的结合有关，至少对于1型胸膜肺炎放线杆菌是这样。通过Folch法从猪肺中提取的一种磷脂也被证明能与胸膜肺炎放线杆菌结合。用钼酸蓝和茚三酮进行化学染色、在中性、酸性和碱性溶剂系统中进行迁移以及质谱分析均表明这种脂质是PE。据我们所知，本研究是对胸膜肺炎放线杆菌与磷脂结合的首次描述。我们的数据还表明LPS O抗原可能参与与PE的结合。
