Clinical and Vaccine Immunology, January 2011, vol. 18, n. 1
Haemophilus parasuis is the agent responsible for causing Glasser’s disease, which is characterized by
fibrinous polyserositis, polyarthritis, and meningitis in pigs. In this study, we have characterized native outer
membrane proteins with affinity to porcine transferrin (NPAPT) from H. parasuis serovar 5, Nagasaki strain.
This pool of proteins was used as antigen to developed two vaccine formulations: one was adjuvanted with a
mineral oil (Montanide IMS 2215 VG PR), while the other was potentiated with a bacterial neuraminidase
from Clostridium perfringens. The potential protective effect conferred by these two vaccines was compared to
that afforded by two other vaccines, consisting of recombinant transferrin-binding protein (rTbp) A or B
fragments from H. parasuis, Nagasaki strain, and by a commercially available inactivated vaccine. Five groups
of colostrum-deprived piglets immunized with the vaccines described above, one group per each vaccine, and
a group of nonvaccinated control animals were challenged intratracheally with a lethal dose (3 108 CFU) of
H. parasuis, Nagasaki strain. The two vaccines containing rTbps yielded similar results with minimal protection
against death, clinical signs, gross and microscopic lesions, and H. parasuis invasion. In contrast, the two
vaccines composed of NPAPT antigen and commercial bacterin resulted in a strong protection against
challenge (without deaths and clinical signs), mild histopathological changes, and no recovery of H. parasuis,
thus suggesting their effectiveness in preventing Glasser’s disease outbreaks caused by serovar 5
