Brockmeier S L, Palmer M V, Bolin S R
Respiratory Diseases of Livestock Research Unit, National Animal Disease Center, USDA, Ames, IA 50010, USA.
Am J Vet Res. 2000 Aug;61(8):892-9. doi: 10.2460/ajvr.2000.61.892.
To examine effects of co-infection with porcine reproductive and respiratory syndrome virus (PRRSV) and Bordetella bronchiseptica in pigs.
Forty 3-week-old pigs. Procedure-30 pigs (10 pigs/group) were inoculated with PRRSV, B bronchiseptica, or both. Ten noninoculated pigs were control animals.
Clinical signs, febrile response, and decreased weight gain were most severe in the group inoculated with both organisms. The PRRSV was isolated from all pigs in both groups inoculated with virus. All pigs in both groups that received PRRSV had gross and microscopic lesions consistent with interstitial pneumonia. Bordetella bronchiseptica was cultured from all pigs in both groups inoculated with that bacterium. Colonization of anatomic sites by B bronchiseptica was comparable between both groups. Pigs in the group that received only B bronchiseptica lacked gross or microscopic lung lesions, and B bronchiseptica was not isolated from lung tissue. In the group inoculated with B bronchiseptica and PRRSV, 3 of 5 pigs 10 days after inoculation and 5 of 5 pigs 21 days after inoculation had gross and microscopic lesions consistent with bacterial bronchopneumonia, and B bronchiseptica was isolated from the lungs of 7 of those 10 pigs.
Clinical disease was exacerbated in co-infected pigs, including an increased febrile response, decreased weight gain, and B bronchiseptica-induced pneumonia. Bordetella bronchiseptica and PRRSV may circulate in a herd and cause subclinical infections. Therefore, co-infection with these organisms may cause clinical respiratory tract disease and leave pigs more susceptible to subsequent infection with opportunistic bacteria.
研究猪繁殖与呼吸综合征病毒（PRRSV）和支气管败血波氏杆菌共感染对猪的影响。
40头3周龄仔猪。实验步骤——30头猪（每组10头）分别接种PRRSV、支气管败血波氏杆菌或两种病原体。10头未接种的猪作为对照动物。
同时接种两种病原体的组临床症状、发热反应和体重增加减少最为严重。在接种病毒的两组所有猪中均分离出PRRSV。接种PRRSV的两组所有猪均有与间质性肺炎一致的大体和显微镜下病变。在接种该细菌的两组所有猪中均培养出支气管败血波氏杆菌。两组支气管败血波氏杆菌在解剖部位的定植情况相当。仅接种支气管败血波氏杆菌的组猪没有大体或显微镜下的肺部病变，且在肺组织中未分离出支气管败血波氏杆菌。在接种支气管败血波氏杆菌和PRRSV的组中，接种后10天5头猪中有3头、接种后21天5头猪中有5头有与细菌性支气管肺炎一致的大体和显微镜下病变，且在这10头猪中的7头猪的肺中分离出支气管败血波氏杆菌。
共感染猪的临床疾病加重，包括发热反应增加、体重增加减少以及支气管败血波氏杆菌引起的肺炎。支气管败血波氏杆菌和PRRSV可能在猪群中传播并引起亚临床感染。因此,这些病原体的共感染可能导致临床呼吸道疾病，并使猪更容易受到随后机会性细菌的感染。
