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The baboon model of Bordetella pertussis infection is the newest and most clinically accurate model of the human disease to date. However, among the 15 experimentally infected baboons in this study, a subset of baboons did not exhibit the expected high bacterial colonization levels or increase in white blood cell count. Moreover, cultures of nasopharyngeal wash samples from several baboons suggested B. bronchiseptica coinfection. Analysis of serum antibodies recognizing filamentous hemagglutinin, pertussis toxin and B. pertussis lipo-oligosaccharide indicated that several baboons had likely been previously exposed to Bordetella species and that prior exposure correlated with partial protection from B. pertussis infection. Notably, all animals with a baseline Fha titer of 5 IU/ml or below exhibited symptoms typical of the model, suggesting this value can be used as inclusion criteria for animals prior to study enrollment. While B. pertussis infection is endemic to human populations and B. bronchiseptica is common in wild small mammals, this study illustrates that baboons can readily harbor both organisms. Awareness of Bordetella species that share antigens capable of generating protective immune responses and tracking of prior exposure to those species is required for successful use of the baboon model of pertussis.

Porcine reproductive and respiratory syndrome virus (PRRSV) is an economically important disease around the globe. Protection against this virus remains problematic. Here, we evaluated antibody (IgG & IgA) inducibility of a heterologous PRRSV glycoprotein 5 (GP5) expressed in a live attenuated Bordetella bronchisepticaaroA mutant strain (BBS-GP5). Mice and pigs were primed with recombinant GP5 (rGP5) subcutaneously followed by boosting with live BBS-GP5. As a result, anti-GP5 IgG was induced in both mice (P<0.001) and pigs (P<0.1). Pigs were challenged with live PRRSV (VR2332). Viral RNA was found to be significantly (P<0.01) removed in the vaccinated pig group. Overall, BBS-GP5 is a good candidate as a live attenuated vaccine against PRRSV infection.

Maesil (Prunus mume) has long been used as a traditional drug and healthy food in East Asian countries. It possesses a number of beneficial biological activities including potential antimicrobial effects against pathogens. Probiotics also have antibacterial effects. Moreover, some probiotics have an important role in regulating the immune system. The present study evaluated the immune enhancing effects of fermented Maesil with probiotics (Saccharomyces cerevisiae, Bacillus subtilis and Lactobacillus acidophilus) in mice, especially against Bordetella bronchiseptica, as an initial step towards the development of feed supplements for the promotion of immune activity and prevention of disease, especially in pigs. Continuous ingestion of fermented Maesil with probiotics markedly increased the macrophage ratio in peripheral blood and the T lymphocyte ratio in the spleen. In addition, antibody production against formalin-killed B. bronchiseptica significantly increased in the mice fed fermented Maesil compared with the control group. The number of leukocytes was significantly higher in the bronchio-alveolar lavage obtained from the fermented Maesil-fed animals compared to it in the control group at day 3 (maximal peak time) after experimental B. bronchiseptica infection. Moreover, at 7 day post-infection, relative messenger RNA expression levels of tumor necrosis factor- α and interferon-γ were significantly increased in splenocytes of mice fed fermented Maesil compared with those in the control group. Taken together, these findings suggest that feed containing fermented Maesil with probiotics enhances immune activity in mice, especially against B. bronchiseptica, via the potent stimulation of non-specific immune responses.

Lipopolysaccharides (LPSs) were purified from Actinobacillus pleuropneumoniae serotype 2, Bordetella bronchiseptica and Haemophilus parasuis serotype 5, which were used for vaccine production in Japan, by the phenol-water procedure. In SDS-PAGE analysis, A. pleuropneumoniae LPS, as well as Escherichia coli LPS, demonstrated a typical ladder profile of a smooth-type LPS. On the other hand, B. bronchiseptica and H. parasuis LPSs lacked the ladder profiles. It was found that the biological activity of these LPSs was comparable to those of E. coli LPS in terms of activation of the clotting enzyme of Limulus amoebocyte lysate, mitogenic activity of mouse spleen cells, stimulation of TNF-alpha and nitric oxide production, but IL-6 production could hardly be observed in any LPS.

The dynamics of toxigenic Bordetella bronchiseptica and Pasteurella multocida infection and the B. bronchiseptica specific antibody content of the blood and nasal secretion were studied in three Hungarian and three Dutch pig herds. In both countries, the studies involved young sows that had farrowed once or twice (YS), old sows that had farrowed more than four times (OS), and their piglets. The results indicate that Dutch sows are characterized by a lower prevalence of B. bronchiseptica and P. multocida infection than Hungarian sows. In Dutch sows and in their piglets, the rate of P. multocida infection was higher than that of B. bronchiseptica infection. The opposite was found for the Hungarian sows and their piglets. B. bronchiseptica infection commenced at 3 and 4 weeks of age in piglets of young and old Dutch sows, respectively, followed by the emergence of P. multocida infection at 5 (YS) and 6 weeks of age (OS). In Hungarian piglets, B. bronchiseptica infection was first demonstrable at 1 (YS) and 3 (OS) while P. multocida infection at 3 (YS) and 5 (OS) weeks of age. The serological tests demonstrated higher B. bronchiseptica specific antibody levels in the Dutch sows and piglets as compared to the Hungarian ones. According to the ELISA results, the levels of IgA and IgG in the serum and those of sIgA, IgA and IgG in the nasal secretion of Dutch sows were significantly (p < 0.001) higher in the Dutch than in the Hungarian piglets up to 3 and 4 weeks of age, respectively.

Although no clinical signs of atrophic rhinitis (AR) were recognized in 2- and 5-week-old pigs, approximately 60% of 2- to 6-month-old pigs showed clinical signs of AR in an affected pig farm. None of the pigs had normal turbinate at slaughter. Bordetella bronchiseptica was not isolated from any of the pigs before onset and incipient stage of the outbreak (2-week to 2-month-old). Pasteurella multocida of capsular type D was not isolated from any of those pigs. However, toxigenic P. multocida of capsular type A was isolated from a number of the pigs immediately before onset and incipient stage of the outbreak. Thirty-six-day-old primary specific-pathogen-free pigs were inoculated intranasally with a toxigenic type A P. multocida isolated from a 5-week-old pig. Severe nasal turbinate atrophy was observed in those pigs which were necropsied at 3 weeks post-inoculation. This is the first report on outbreak of severe nasal turbinate atrophy induced by toxigenic type A P. multocida in Japan.

The cell-free antigen (CFA), with highly hemagglutination activity, obtained from the culture supernatant of Bordetella bronchiseptica was compounded with oil adjuvant to make a component vaccine (CFAV). In the immunization trial in mice, the offsprings whose mothers were immunized with CFAV escaped from death when challenged intrapleurally with virulent strain of B. bronchiseptica. The protective indices (difference of LD50 dose of the challenge strain between immunized and control groups) of the offsprings from CFAV-immunized mothers were over 3.0 in common logarithm value. Moreover, about 90% of the offsprings from CFAV-immunized mothers were negative in nasal turbinate atrophy, while over 80% of them from non-immunized mothers showed obvious turbinate atrophy when challenged intranasally with virulent strain. On the one hand, remarkable differences in the number of bacteria recovered from nostrils were observed between both test groups. It was concluded that CFAV is a very effective vaccine against B. bronchiseptica infection in animals.