Rogers R J, Eaves L E, Blackall P J, Truman K F
Department of Primary Industries, Animal Research Institute, Yeerongpilly, Queensland.
Aust Vet J. 1990 Jan;67(1):9-12. doi: 10.1111/j.1751-0813.1990.tb07382.x.
The pathogenicity of 2 isolates of each of serovars 7, 3, 1 and 2 of Actinobacillus pleuropneumoniae was tested by intranasal inoculation into 60, 6-week-old large white pigs. Four dose rates varying from 0.27 to 560 x 10(6) organisms per pig with 10-fold serial dilutions were used. Surviving pigs were necropsied 7 days after inoculation. The proportion of pigs dying and developing gross lesions following infection was significantly greater for pigs given serotype 1 than for each of the other 3 serotypes, which did not differ significantly from each other. Twelve of 16 pigs given either of the 2 isolates of serovar 1 died after acute illness and 1 of 44 pigs given either of the 2 isolates each of serovars 7, 3 and 2 died. Pigs given serovar 1 showed high temperatures, severe respiratory distress, frothy haemorrhagic nasal discharge and weight loss. Lung lesions were produced in all 16 pigs given serovar 1, in 7 of 14 pigs given serovar 7, 7 of 14 pigs receiving serovar 3 and in 5 of 16 pigs given serovar 2. The lethal infections were characterised by a severe acute fibrinohaemorrhagic necrotising pleuropneumonia, whereas non-lethal cases had lung lesions ranging from necrotising purulent pleuropneumonia to abscessation. Significant differences between isolates in proportions of tissues culture positive for A. pleuropneumoniae for serovars 7 and 2, but not for serovars 3 and 1 suggested that isolates may vary in virulence within serovars, but more detailed studies are needed to clarify this point.
通过向60头6周龄的大白猪鼻腔内接种，对胸膜肺炎放线杆菌血清型7、3、1和2的各2株分离株的致病性进行了测试。使用了四种剂量率，每头猪的菌量从0.27至560×10⁶个，按10倍系列稀释。接种后7天对存活的猪进行剖检。感染后死亡和出现肉眼可见病变的猪的比例，血清型1的猪显著高于其他3种血清型，后3种血清型之间无显著差异。接种血清型1的2株分离株之一的16头猪中有12头在急性发病后死亡，接种血清型7、3和2的2株分离株之一的44头猪中有1头死亡。接种血清型1的猪出现高热、严重呼吸窘迫、泡沫状出血性鼻液和体重减轻。接种血清型1的所有16头猪都出现了肺部病变，接种血清型7的14头猪中有7头、接种血清型3的14头猪中有7头以及接种血清型2的16头猪中有5头出现了肺部病变。致死性感染的特征是严重的急性纤维蛋白出血性坏死性胸膜肺炎，而非致死性病例的肺部病变范围从坏死性化脓性胸膜肺炎到脓肿形成。血清型7和2的分离株在胸膜肺炎放线杆菌组织培养阳性比例上存在显著差异，但血清型3和1没有，这表明同一血清型内的分离株毒力可能不同，但需要更详细的研究来阐明这一点。
