Immunization with Streptococcus suis bacterin plus recombinant Sao protein in sows conveys passive immunity to their piglets

Abstract

Background Streptococcus suis (S. suis) causes arthritis, meningitis, septicemia, and sudden death in pigs and is also an zoonotic agent for humans. The present study demonstrated that immunization with recombinant Sao-L (surface antigen one-L, rSao-L) protein from a strain of S. suis serotype 2 in pigs was able to increase cross-serotype protection against S. suis serotype 1 and 2 challenge. Since weaning piglets are more susceptible to S. suis infections due to the stresses associated with weaning, prepartum immunization in sows may convey passive immunity to piglets and provide protection.ResultsPregnant sows were immunized with a vaccine containing inactivated S. suis serotype 2 plus rSao as the antigens. Blood samples were collected from their piglets after birth for analysis of antigen-specific antibody titers and levels of various cytokines. Results demonstrated that the titers of S. suis and rSao-specific antibodies were significantly (p < 0.05) higher in the vaccinated piglets in comparison with that of piglets in the control group. The serum levels of interferon (IFN)-γ, interleukin (IL)-4, IL-6, and IL-12 were significantly (p < 0.05) increased in piglets born from vaccinated sows when compared to piglets from unvaccinated sows. In addition, piglets were challenged by heterologous and homologous S. suis. All piglets from unvaccinated sows developed severe symptoms of bacteremia, fever, anorexia, depression, and arthritis. On the other hand, piglets from vaccinated sows had significantly (p < 0.05) reduced clinical symptoms and lesion score (by 75 and 81%).ConclusionsOur results revealed that immunizing pregnant sows with the vaccine containing inactivated S. suis bacterin plus rSao as the antigens is able to enhance passive immunity against heterologous and homologous S. suis challenge in their piglets.

Immunogenicity study of a Streptococcus suis autogenous vaccine in preparturient sows and evaluation of passive maternal immunity in piglets

“…Finally, sow immunization with S. suis serotype 2 bacterin plus recombinant “surface antigen one” (Sao) protein resulted in increased levels of specific antibodies, against the whole bacteria and Sao, in piglets. Interestingly, the serum titer against whole bacteria, but not Sao, was remarkably reduced in piglets at 6 week-old [ 18 ].…”

“…Bacterin hyperimmunization is an old, still successful, approach to induce high levels of antibodies that was reported in the 90s [ 12 ]. The aforementioned experimental sow vaccination studies either used water-in-oil-in water (w/o/w) adjuvant [ 18 ], Emulsigen® [ 5 ] or an oil-in-water emulsion [ 17 ]. These divergent formulations, including the addition of a recombinant protein in the study by Hsueh et al [ 18 ], might explain differences in antibody levels, antibody quality (see below), duration of maternal immunity in piglets and, when evaluated, protective capacity.…”

Isolation and identification of Streptococcus suis from sick pigs in Bali, Indonesia

“…The fragment of GDH or recN might be used to map infections in Indonesia. Vaccines can be developed using inactivated strain [33] to reduce economic losses and the risk of human infection, including among domestic and international travelers.…”

Protective Effect of Recombinant Proteins of Cronobacter Sakazakii During Pregnancy on the Offspring

“…Compared with the control group, the progeny of the protein-immunized groups had higher levels of cytokines (Figures 8A,B). The cytokines in the progeny serum may be mainly derived from the absorption of maternal cytokines in the colostrum (Hsueh et al, 2016). Passive transfer of cytokines and antibodies further affects the cytokine secretion capacity of neonatal spleen cells (Elahi et al, 2017).…”