Mycoplasmal Pneumonia Of Swine Research Articles

Immune Responses to the Attenuated Mycoplasma hyopneumoniae 168 Strain Vaccine by Intrapulmonic Immunization in Piglets

To investigate the immune responses to the attenuated Mycoplasma hyopneumoniae 168 strain vaccine, 8-15 d old piglets were immunized with M. hyopneumoniae 168 strain vaccine by intrapulmonic route. And the specific IgG antibody in serum, lymphoproliferation, IFNγ, and specific secretory IgA (SIgA) antibody in bronchoalveolar lavage fluid were detected on 30 and 60 d post-immunization (DPI), respectively. On 60 DPI, all the pigs except for those in health control group were challenged with a field M. hyopneumoniae strain JS. Necropsy was performed on 30 d post-challenge (DPC). The results showed that IFNγ and specific SIgA were stimulated on surface of respiratory tract after immunization. And peripheral blood mononuclear cells could also be proliferated about 1.81 and 2.12 fold on 30 and 60 DPI when stimulated by M. hyopneumoniae protein in vitro. However, no serum IgG antibody against M. hyopneumoniae was detected during the whole immune phage. After challenge, vaccinated pigs were observed with only very slight histological lesion in individual lobes. None of vaccinated pigs showed any clinical signs. While the unvaccinated pigs from challenge control group showed varying degrees of clinical sign and severe macroscopical lesion of mycoplasmal pneumonia of swine (MPS). The result suggested that the attenuated M. hyopneumoniae 168 strain vaccine inoculated by intrapulmonic route could activate the systemic cellular immunity, the local mucosal immunity and IFNγ secretion in respiratory tract to against M. hyopneumoniae infection in piglets.

Oral vaccination against mycoplasmal pneumonia of swine using a live Erysipelothrix rhusiopathiae vaccine strain as a vector

Erysipelothrix rhusiopathiae Koganei 65-0.15 strain, the live swine erysipelas vaccine for subcutaneous injection, has been shown to colonize the tonsils of pigs after oral inoculation. We thus evaluated the possible use of the strain as a vector for oral vaccination against mycoplasmal pneumonia of swine. Recombinant E. rhusiopathiae strains expressing the C-terminal domain of the P97 adhesin of Mycoplasma hyopneumoniae were constructed and examined for vaccine efficacy in mice and pigs. Mice subcutaneously inoculated with the recombinant strains were protected from challenge exposure to a virulent E. rhusiopathiae. Administration of milk replacer containing recombinant E. rhusiopathiae expressing the M. hyopneumoniae protein protected pigs from death after exposure to E. rhusiopathiae and significantly reduced the severity of pneumonic lung lesions caused by infection with M. hyopneumoniae.

Vaccine efficacy of the attenuated Erysipelothrix rhusiopathiae YS-19 expressing a recombinant protein of Mycoplasma hyopneumoniae P97 adhesin against mycoplasmal pneumonia of swine

The attenuated Erysipelothrix rhusiopathiae YS-19 strain was constructed for the purpose of delivering the C-terminal portion of the Mycoplasma hyopneumoniae P97 adhesin to the mucosal surface of the respiratory tract of pigs. In this study, the efficacy of the YS-19 vaccine against mycoplasmal pneumonia of swine was evaluated. Animal experiments revealed that intranasal immunization of pigs with the YS-19 strain significantly reduced the severity of pneumonic lung lesions caused by M. hyopneumoniae infection. In YS-19-immunized pigs, P97-specific serum antibodies were not detected. However, when stimulated with the P97 protein, peripheral blood mononuclear cells from the YS-19-immunized pigs had a significantly higher stimulation index ( P<0.05) than that of cells from control pigs at 7 days post-challenge.

と畜検査データに基づく養豚農家における豚マイコプラズマ肺炎の防除対策

と畜検査データに基づく養豚農家における豚マイコプラズマ肺炎の防除対策

Failure of lungworm-larvae-infected earthworms to transmit mycoplasmal pneumonia to swine

Two herds of swine, believed to be free from mycoplasmal pneumonia of swine (MPS) based upon negative Mycoplasma hyopneumoniae microtiter complement fixation test (CFT) results, subsequently exhibited clinical signs of MPS. Lungworms ( Metastrongylus spp.) were common to both herds. The possibility that lungworms could serve as a reservoir for M. hyopneumoniae was investigated. Lungworm-larvae-infected earthworms, collected from each of the farms, were fed to swine free of lungworms and MPS. This procedure resulted in lungworm infection in the recipient pigs, but failed to produce pneumonic lesions or CFT antibody titers against MPS.

Response of swine to Mycoplasma hyopneumoniae infection.

Mycoplasmal pneumonia of swine offers a useful and economically significant model to study many aspects of chronic mycoplasmal pneumonia. Although the available information is very meager about areas of this disease, there are some very interesting aspects to this model. Infection with Mycoplasma hyopneumoniae is common in swine. From 35% to 60% of so-called normal market swine have gross lesions typical of this disease. Such surveys conducted at packing plants do not answer the question of whether a very high percentage of certain herds and a very low percentage of others are infected, or if from 35% to 60% of almost every swine herd is infected. Limited field observations indicate that the