Nielsen J P, Foged N T, Sørensen V, Barfod K, Bording A, Petersen S K
National Veterinary Laboratory, Animal Biotechnology Research Centre, Copenhagen, Denmark.
Can J Vet Res. 1991 Apr;55(2):128-38.
Vaccination against progressive atrophic rhinitis using a purified recombinant derivative of the Pasteurella multocida toxin (PMT), was carried out. Ten pregnant gilts were vaccinated twice with the nontoxic derivative (dO) which apart from a lack of 121 amino acids had an amino acid sequence identical to PMT, while seven gilts were vaccinated with a purified, formaldehyde treated, native PMT and ten gilts served as non-vaccinated controls. The resulting piglets were inoculated intranasally with Bordetella bronchiseptica and toxigenic P. multocida. Among piglets from the nonvaccinated gilts all except one developed clinical atrophic rhinitis and 90% developed severe turbinate atrophy while only a few pigs in the vaccinated groups developed clinical or pathological signs of disease. Gilt colostra from the two vaccinated groups had similar mean anti-PMT titers and the mean titers in the offspring's sera from these groups were nearly identical throughout the study. No pigs born from unvaccinated gilts were seropositive until 8 wk of age (7 wk post-challenge) but 23% became seropositive at slaughter. The infection rate with toxigenic P. multocida in piglets and the total number of P. multocida colonies cultured from nasal swabs were significantly reduced at 5 wk and 8 wk of age in the vaccinated groups, when compared to controls. There was a significantly improved weight gain (greater than 9%) from birth to slaughter in offspring from vaccinated gilts. No significant differences in feed conversion rate or % lean meat were observed among the groups. The study showed the excellent immunoprotective properties of the nontoxic derivative of the PMT molecule.
使用多杀性巴氏杆菌毒素（PMT）的纯化重组衍生物对进行性萎缩性鼻炎进行了疫苗接种。十头怀孕的后备母猪用无毒衍生物（dO）进行了两次疫苗接种，该衍生物除了缺少121个氨基酸外，其氨基酸序列与PMT相同，而七头后备母猪用纯化的、经甲醛处理的天然PMT进行了疫苗接种，十头后备母猪作为未接种疫苗的对照。将产生的仔猪经鼻接种支气管败血波氏杆菌和产毒素多杀性巴氏杆菌。在未接种疫苗的后备母猪所产的仔猪中，除一头外，所有仔猪均出现临床萎缩性鼻炎，90%出现严重鼻甲萎缩，而接种疫苗组中只有少数猪出现疾病的临床或病理体征。两个接种疫苗组的后备母猪初乳平均抗PMT滴度相似，在整个研究过程中，这些组后代血清中的平均滴度几乎相同。未接种疫苗的后备母猪所产的仔猪直到8周龄（攻毒后7周）均无血清阳性，但在屠宰时有23%变为血清阳性。与对照组相比，接种疫苗组仔猪中产毒素多杀性巴氏杆菌的感染率以及从鼻拭子培养的多杀性巴氏杆菌菌落总数在5周龄和8周龄时显著降低。接种疫苗的后备母猪所产后代从出生到屠宰的体重增加显著改善（超过9%）。各组之间在饲料转化率或瘦肉率方面未观察到显著差异。该研究表明了PMT分子无毒衍生物具有优异的免疫保护特性。
