RESUMO
Endotoxin is recognized as one of the virulence factors of the Bordetella avium bird pathogen, and characterization of its structure and corresponding genomic features are important for an understanding of its role in pathogenicity and for an improved general knowledge of Bordetella spp virulence factors. The structure of the biologically active part of B. avium LPS, lipid A, is described and compared to those of another bird pathogen, opportunistic in humans, Bordetella hinzii, and to that of Bordetella trematum, a human pathogen. Sequence analyses showed that the three strains have homologues of acyl-chain modifying enzymes PagL, PagP and LpxO, of the 1-phosphatase LpxE, in addition to LgmA, LgmB and LgmC, which are required for the glucosamine modification. MALDI mass spectrometry identified a high amount of glucosamine substituting the phosphate groups of B. avium lipid A; this modification was absent from B. hinzii and B. trematum. The acylation patterns of the three lipid As were similar, but they differed from those of Bordetella pertussis and Bordetella parapertussis. They were also found to be close to the lipid A structure of Bordetella bronchiseptica, a mammalian pathogen, only differing from the latter by the degree of hydroxylation of the branched fatty acid.
Assuntos
Bordetella avium/química , Bordetella/química , Lipídeo A/química , Sequência de Aminoácidos , Bordetella/genética , Bordetella avium/genética , Endotoxinas/farmacologia , Ácidos Graxos/química , Genoma Bacteriano/genética , Glucosamina/química , Humanos , Hidrólise , Lipídeo A/genética , Lipopolissacarídeos/farmacologia , Dados de Sequência Molecular , Fosfatos/químicaRESUMO
To study the immunogenicity of Bordetella avium OMP, ultrasonic dispersion, TritonX-100 technique were used to extract Bordetella avium OMP. Its content was determined by Bradford method and it was detected by SDS-PAGE. Then OMP immunizing antigen was prepared and 1-day chicken was vaccinated by hypodermic inoculation, with the immunizing does of 0.3mL (OMP90microg), 0.5mL (OMP150microg), 0.8mL (OMP240microg), respectively. Results showed that content of Bordetella avium OMP is 300 g/mL, the best immunizing does is 0.5mL each one and Chickens can be protected against Bordetella avium at fetal dose if antibody titer is over 1:2(8). We can see from the antibody level detected by indirect ELISA that antibody can last long enough to help chickens pass susceptible period, so OMP has good immunogenicity. Results of this study lay good foundation for the development of monoclonal antibody to OMP, rapid diagnosis kit and subunit vaccine.
