Sanford S E, Josephson G K, Rehmtulla A J, Tilker A M
Can Vet J. 1990 Jun;31(6):443-7.
Actinobacillus suis was isolated from tissues of 39 pigs, 2 porcine lungs, and 1 uterine swab submitted for diagnostic evaluation from 24 farms in southwestern Ontario between 1985 and 1988. These isolates represented a gradually increasing incidence of herd outbreaks caused by A. suis in southwestern Ontario. The outbreaks were typified by sudden death in suckling or recently weaned pigs; 87% of the affected pigs examined at the laboratory were between two and 28 days old. Petechial to ecchymotic hemorrhages in the thoracic and abdominal organs accompanied by serofibrinous exudates in both cavities were the most common gross lesions. The lesions were characterized histologically by bacterial thromboembolism and necrosis randomly scattered in thoracic and abdominal organs. Occasionally, bacterial thromboemboli were surrounded by centrifugally radiating, eosinophilic, club-like colonies. Diffuse necrohemorrhagic myocarditis that was more severe in the atria, and diffuse subacute meningoencephalitis, were less frequent but distinctive lesions. Multiple litters were affected in most herd outbreaks, and mortality often approached 50% in affected litters. Although the A. suis organism was susceptible to nearly every antibiotic against which it was tested, the suddenness of herd outbreaks precluded attempts at treatment.
1985年至1988年间，从安大略省西南部24个农场送来进行诊断评估的39头猪的组织、2个猪肺和1份子宫拭子中分离出猪放线杆菌。这些分离株表明安大略省西南部由猪放线杆菌引起的猪群疫情发病率在逐渐上升。疫情的典型特征是哺乳仔猪或刚断奶仔猪突然死亡；在实验室检查的受影响猪中，87%的猪年龄在2至28日龄之间。胸腹部器官出现点状至瘀斑状出血，同时伴有胸腔和腹腔的浆液纤维素性渗出物，是最常见的大体病变。组织学上，病变的特征是细菌血栓栓塞和坏死随机散布于胸腹部器官。偶尔，细菌血栓栓子周围会有呈离心状辐射的嗜酸性棒状菌落。弥漫性坏死性出血性心肌炎在心房更为严重，以及弥漫性亚急性脑膜脑炎，虽不太常见但具有特征性。在大多数猪群疫情中，多窝仔猪都会受到影响，受影响窝的死亡率通常接近50%。尽管猪放线杆菌对几乎所有测试过的抗生素都敏感，但猪群疫情的突发性使得治疗尝试无法进行。
