【摘要】 人工感染猪霉形体肺炎自然病愈猪40头,用微粒凝集反应,定期测定血清中凝集素消长情况。测得病愈后601～661天,仍可检出凝集抗体。分别用病愈猪肺悬液接种健猪,能部分感染致病。用“活体分离法”和“病肺块接种法”分离培养出的病原菌,经血清学鉴定,证实为猪肺炎霉形体,并能对健猪致病。实验证明:人工感染病愈猪中部分猪只的带菌期至少在601天以上,仍有传染性。因此,病愈母猪不适宜作种猪繁殖用。更多还原

【Abstract】 To detect carriers of Mycoplasma hyopneumoniae, an experiment consisting of 40 pigs including 22 locally bred er-hua-lian-middle drawn face pigs and 18 Yerkshire x er-hua-lian hybrids was carried out. All of the pigs bought from a farm free from mycoplasmal pneumonia were instillated nasally with the homogenized lungs of pigs infected with mycoplasmal pneumonia. Most of them showed lesions in the lungs when the chests were examined by X-ray about two weeks post-infection.The pigs recovered within 2-3 months. After both clinical signs and lung lesions of all pigs had completely disappeared, the pigs were examined periodically with microagglutination tests, isolations of M .hyopneumoniae by nasal swabs and finally with autopsies.One-hundred-and-thirty-six to 661 days after recovery all the 40 pigs showed positive reactions to micro-agglutination tests, except one(#83, recovered 661 days later ) with " ± " sign. From 2 er-hua-lian pigs M. hyopneumoniae was isolated by nasal swabs 418-421 days after recovery,and also from the lungs with minimal lesions 641-643 days after recovery in autopsies. The isolates were serologically identified as M.hyopneumoniae,and could induce pneumoniae by nasal instillations. From the lungs of 3 pigs of Yorkshire x er-hua-lian, M. hyopneumoniae was isolated by nasal swab cultures 614-661 days after recovery and upon autopsy performed 664-661 days after recovery. The lung suspensions from these 3 pigs could induce mycoplasmal pneumonia in 5 out of 6 pigs by nasal instillations, and from the lungs of them M .hyopneumoniae were also recovered.The results demonstrated that the sows once infected with mycoplasmal pneumonia, even after long periods of convalescence ( 661 days as recorded in this experiment ) , can not be used for breeding a mycoplasmal pneumonia free herd.更多还原