Kobisch M, Blanchard B, Le Potier M F
Centre National d'Etudes Vétérinaires et Alimentaires, Laboratoire Central de Recherches Avicole, Ploufragan, France.
Vet Res. 1993;24(1):67-77.
Forty-eight hysterectomy produced piglets reared in a pathogen-free environment were housed in 4 separate units. Three groups were intratracheally challenged with M hyopneumoniae at 2 wk, or at 16 wk, or at 2 and 16 wk of age. The fourth group was uninfected and received broth medium. Coughing started 2 weeks after the first infection but the booster infection did not induce any coughing. Macroscopic lesions, typical of mycoplasmal pneumonia, were noted 1 wk post-infection. After 7-9 wk, piglets showed recovering lesions. In the group that was twice infected, only 1 pig had extensive pneumonia after the second infection. The remaining pigs only had recovering lesions (RL) (resulting from the first challenge). Histopathology and scanning electron microscopy confirmed the macroscopic observations. Antibodies were detected by ELISA and immunoblotting at 3-4 wk post-infection, peaking after 11-12 wk and then gradually decreasing. However, the antibody response increased after the second infection. These findings showed a noticeable recovery following infection with M hyopneumoniae and a clear resistance to pneumonia following the booster infection.
四十八只在无病原体环境中饲养的经子宫切除的仔猪被安置在4个独立的单元中。三组仔猪分别在2周龄、16周龄或2周龄和16周龄时经气管接种猪肺炎支原体。第四组未感染，接受肉汤培养基。首次感染后2周开始出现咳嗽，但再次感染未引发任何咳嗽。感染后1周观察到支原体肺炎典型的宏观病变。7 - 9周后，仔猪出现恢复性病变。在两次感染的组中，第二次感染后只有1头猪患有广泛性肺炎。其余猪只有恢复性病变（由首次攻击引起）。组织病理学和扫描电子显微镜证实了宏观观察结果。感染后3 - 4周通过ELISA和免疫印迹检测到抗体，在11 - 12周后达到峰值，然后逐渐下降。然而，第二次感染后抗体反应增强。这些发现表明感染猪肺炎支原体后有明显的恢复，再次感染后对肺炎有明显的抵抗力。
