Department of Pathobiology and Population Sciences, Royal Veterinary College, North Mymms, Hertfordshire, UK.
Department of Pathobiology and Population Sciences, Royal Veterinary College, North Mymms, Hertfordshire, UK.
J Comp Pathol. 2022 Jul;195:12-18. doi: 10.1016/j.jcpa.2022.04.004. Epub 2022 May 30.
In-vivo models of Actinobacillus pleuropneumoniae (App) infection in pigs are required for the development of vaccines and investigations of pathogenicity. Existing models cause severe respiratory disease with pulmonary oedema, dyspnoea and severe thoracic pain, and careful monitoring and early intervention with euthanasia is, therefore, needed to avoid unnecessary suffering in experimental animals. As a potential replacement for the existing respiratory infection model, an in-vivo protocol was evaluated using intradermal or subcutaneous injection of different App strains and Apx toxins into the abdominal skin of pigs. High concentrations of serovar 1 and serovar 10 App induced diffuse visible dermal oedema and inflammation. Injection of Apx toxins alone did not adequately produce macroscopic lesions, although an influx of inflammatory cells was seen on histopathology. ApxI-producing strains of App induced more inflammation than ApxII- and ApxIII-producing strains. Induction of skin lesions by injection of App or Apx toxins was not sufficiently repeatable or discrete for a robust experimental model that could be used for assessment of novel interventions.
为了开发疫苗和研究致病性，需要在猪体内建立胸膜肺炎放线杆菌（App）感染的模型。现有的模型会导致严重的呼吸道疾病，伴有肺水肿、呼吸困难和严重的胸痛，因此需要进行仔细的监测并尽早进行安乐死，以避免实验动物遭受不必要的痛苦。作为现有呼吸道感染模型的潜在替代品，本研究评估了一种通过皮内或皮下注射不同 App 菌株和 Apx 毒素到猪腹部皮肤的体内方案。高浓度的血清型 1 和血清型 10 App 引起弥漫性可见的皮肤水肿和炎症。单独注射 Apx 毒素不能充分产生肉眼可见的病变，尽管组织病理学检查显示炎症细胞浸润。产生 ApxI 的 App 菌株比产生 ApxII 和 ApxIII 的菌株引起更多的炎症。通过注射 App 或 Apx 毒素诱导皮肤病变的重复性和离散性不足以建立一个稳健的实验模型，该模型可用于评估新的干预措施。
